Saimaa University of Applied Sciences Technology, Lappeenranta

Saimaa University of Applied Sciences Technology, Lappeenranta
Saimaa University of Applied Sciences
Technology, Lappeenranta
Double Degree Programme in Civil and Construction Engineering
Viunov Valerii
COMPARISON OF SCAFFOLDING SYSTEMS
IN FINLAND AND IN RUSSIA
Bachelor’s Thesis 2011
ABSTRACT
Valerii Viunov
Comparison of Scaffolding Systems in Finland and in Russia,
66 pages, 5 appendices
Saimaa University of Applied Sciences, Lappeenranta
Technology, Double Degree Programme in Civil and Construction Engineering
Bachelor’s Thesis 2011
Tutors: Petri Vauhkonen, Kirsi Taivalantti, Pekka Roitto
The purpose of this work was to study the present situation with scaffolding in
Finland and in Russia in order to reveal differences between the systems
themselves, to compare the regulations applied to scaffolding in both countries,
and of course, to consider the competitiveness of European systems in Russia.
The best Russian scaffolding products were chosen and compared with
German scaffolding, which is in common use in Finland.
Some information provided in this study is unique since the huge part of images
and materials was obtained during the direct conversation with manufacturer’s
representatives.
Russian legislation system, being constantly subjected to changes, is not
novice-friendly. It took plenty of time to distinguish, which of the documents are
in their power and have to be followed. During the process of studying them it
was important to check all the time that they do not contradict each other.
Necessary documents that must be prepared and taken care of during the
process of scaffolding assemblage and use were defined, being sometimes a
confusing task for even the professionals in the field.
Comparison clearly showed that Russian scaffolding systems have not reached
the European level yet and this mostly comes from the demand. Building
companies are usually interested in the cheapest offers possible.
Although the prices of foreign scaffolding systems are much higher, the
advantages of higher-quality products are slowly becoming to be realized. The
expansion of high-quality systems will definitely push Russian manufacturers to
improve their products. And this study showed that the development is already
noticeable. Some manufacturers are trying to improve their systems, bringing
innovative ideas to design of their joints or to production process.
And from the work safety point of view it is definitely the step forward, because
scaffolding itself ever stays to be a business of a very high risk.
Keywords: scaffolding, modular system, mobile scaffolding, fabricated frame,
tube-and-coupler, handover certificate, work safety.
CONTENTS
1 INTRODUCTION ............................................................................................ 5
2 FUNDAMENTALS OF MODERN DAY SCAFFOLDING ................................. 6
3 BASIC SCAFFOLDING TERMS ................................................................... 11
4 MAIN TYPES OF SCAFFOLDING SYSTEMS.............................................. 13
4.1 Modular scaffolding .............................................................................. 13
4.1.1 Introduction to modular scaffolding ...................................................... 13
4.1.2 Cup-Lock modular scaffolding system.................................................. 14
4.1.3 Ring-Lock modular scaffolding system ................................................. 15
4.2 Tube-and-Coupler scaffolding .............................................................. 18
4.3 Fabricated frame scaffolding ................................................................ 20
4.4 Mobile scaffolding ................................................................................ 22
5 MAIN RUSSIAN MANUFACTURERS OF MODULAR SCAFFOLDING
SYSTEMS .................................................................................................... 24
5.1 RINSTROY Ltd. .................................................................................... 24
5.2 MDN-Prom Ltd. .................................................................................... 27
5.3 Monolit Stroy Komplekt Ltd. (MSK) ...................................................... 30
5.4 SIMAN+ Ltd. ......................................................................................... 31
6 COMPARATIVE ANALYSIS OF RUSSIAN RING-LOCK SCAFFOLDING
SYSTEMS .................................................................................................... 35
7 COMPARISON OF RUSSIAN SCAFFOLDING SYSTEMS WITH THE ONES
COMMONLY USED IN FINLAND ................................................................. 39
8 RUSSIAN REGULATORY DEMANDS FOR SCAFFOLDING ...................... 43
8.1 Introduction to Russian standardization system ................................... 43
8.2 Documents to carry about when performing assembly of scaffolding .. 46
8.3 Demands applied to scaffolding ........................................................... 48
9 COMPARISON OF RUSSIAN AND FINNISH SAFETY REQUIREMENTS
FOR SCAFFOLDING.................................................................................... 54
10 WORK SAFETY IN PRACTICE ................................................................. 58
11 SUMMARY ................................................................................................ 61
12 FIGURES ................................................................................................... 63
13 TABLES ..................................................................................................... 65
14 REFERENCES .......................................................................................... 66
APPENDICES
Appendix 1 Russian scaffolding assembly and use poster
Appendix 2 Scaffolding handover certificate
Appendix 3 Journal of acceptance and visual examination of scaffolding
Appendix 4 Work site safety walk-around report
Appendix 5 Job titles on Russian building sites
1 INTRODUCTION
Scaffolding is a temporary structure used to support people and material in the
construction or repair of buildings and other large objects. Commonly being
high-raised means that work safety becomes the main thing to take care about.
Manufacturers all over the world are challenged to create the systems, which
are versatile, safe, long-lasting and fast to assemble. They are trying to find the
balance between the price and the quality. The most popular European
scaffolding manufacturers are located in Germany. Their systems are widely
used in Finland since they proved to be safe and meet the strictest demands of
complicated construction projects.
If we take Russia, the situation is different. The country has her own
manufacturers of scaffolding systems and foreign ones are very seldom can be
spotted on Russian building sites. Although, during the last few years, some
European companies started their business in Russia and brought new
scaffolding systems to the country’s huge market.
The present study is devoted to finding the advantages and disadvantages of
Russian-made scaffolding and comparing it with European analogues. To
perform it, the modular scaffolding was chosen as being nowadays the most
advanced system on the world market.
In addition to scaffolding material itself, the comparison was made between
Finnish and Russian legislation that deals with scaffolding and work safety at
heights, being the valuable information for ones who plan starting business in
Russia. Great attention was paid to description of present situation with Russian
regulation system as well as to explanation of different normative documents
and certificates.
5
2 FUNDAMENTALS OF MODERN DAY SCAFFOLDING
Scaffolding has been used ever since man began making buildings more than
one storey high and needed to find a practical way of working at height.
Although the materials and designs have changed over the centuries, the
purpose of scaffolding remains the same – to provide a safe, temporary
platform from which all types of construction, repair and maintenance work can
be carried out.
There are different types of scaffolding, but usually they are all made up of the
same basic components: tubes and boards. What actually varies much is the
way of connecting the tubes together. In so-called tube-and-clamp system tubes
are attached to each other by special couplers. Fabricated frame system
provides the ready-made frames, which only need to be braced to ensure the
rigidness of the whole system. The most up-to-date modular systems feature
special joints that simplify the assembly process. They also provide the
rigidness of the joints in addition to high versatility of the whole system. Modular
scaffolding can reach great heights, retracing the complex shape of structure.
Below is the Figure 1 showing the renovation of Landwasser Viaduct in
Switzerland, during which the modular scaffolding was used.
Figure 1 Modular scaffolding - renovation of the Landwasser Viaduct in
Switzerland
6
Scaffolding mainly consists of tubes. Tubes for scaffolding nowadays are either
steel or aluminium. If steel they are usually painted or galvanized. Figure 2
illustrates the variety of materials, commonly used for scaffolding structures.
Painted steel
Aluminium
Steel
Hot-dip galvanized steel
Figure 2 Scheme of scaffolding materials and their treatment
Galvanization originally refers to any of several electrochemical processes
named after the Italian scientist Luigi Galvani. These processes are used to add
a thin layer of another metal to a ferrous substrate, in order to prevent rusting.
Though, the term has been widened in common usage to include applying a
protective zinc layer to a piece of metal, using a process called Hot-dip
galvanizing, which does not employ electrochemical deposition. It is done by
passing the metal through a molten bath of zinc at temperatures around 460 °C.
This is a usual way to treat scaffolding tubes. The practical difference is that hot
dip zinc galvanizing produces a much thicker, durable coating, whereas genuine
galvanizing produces a very thin coating. The thin coating produced by is much
more quickly consumed, after which corrosion turns to the steel itself. This
makes genuine galvanizing unsuitable for outdoor applications like scaffolding.
Visually it is possible to determine which process has been used: genuine
galvanizing produces a nice, shiny surface, whereas hot dip zinc coating
produces a matte, grey surface. But usually, when talking about scaffolding and
mentioning the galvanized finish it is meant that its tubes are hot-dip galvanized.
7
Galvanized tubes are more expensive than painted ones, but they last much
longer. Figure 3 shows two cases of scratching the protective coating. In the
first case it is zinc coating and in the second the metal surface is painted.
Zinc coating
Paint
Blister
Sacrificial action
Rust
Figure 3 Scratch consequences on zinc-coated and painted metal pieces
The reason for the extensive use of hot-dip galvanizing is the two-fold protective
nature of the coating. As a barrier coating it provides a tough, metallurgicallybonded zinc coating that completely covers the steel surface and seals the steel
from the corrosion action of the environment. Additionally, the sacrificial action
of zinc protects the steel even when damage occurs in the coating (Levy 2000,
p.213). Zinc is more active metal, which have a greater tendency to lose
electrons than less active steel. When zinc and steel are connected in the
presence of the electrolyte (rain water), the zinc is slowly consumed, while the
steel is protected. Zinc offers enough protection in small exposed areas such as
scratches or drill holes. It is a great way to prolong the life of the element.
An item which is only painted will rust if scratched. The exposed steel corrodes
and forms a rust pocket. Because rust has greater volume than steel, the
pocket swells. This lifts a paint film from the metal surface to form a blister. Both
the corrosion pocket with rust and the blister continue to grow.
One more important thing to mention is that it is quite complicated process to
paint the tube from the inside. That is why for scaffolding only outer surface is
painted. But with hot-dip galvanizing things are different. When the tube is
passed through the molten bath of zinc the coating is applied to every surface –
8
outer and inner as well. That is the one more advantage of galvanized
scaffolding tubes.
Another scaffolding material that should be mentioned is Bamboo. It has been
used throughout history and survived over generations. In Asia today people
still practice the traditional bamboo scaffolding. Workers build frames which are
durable enough to support the weight of themselves, their equipment and
materials while they work. It is a common sight in Asia to see these bamboo
structures spanning the entire height of buildings and office blocks (Find
Scaffolding website, 2011). On Figure 4 there are two photos taken in Hong
Kong showing how high and complicated can be the bamboo scaffolding.
Figure 4 Bamboo high-rise scaffolding in Hong Kong, China
As bamboo is a light, portable material it is easy to move from site to site. This
light weight and surprising durability means that no machinery is needed to
assemble the scaffold and put it in place. The main thing about bamboo
scaffolding is that safety and effectiveness of the bamboo scaffolds depends
primarily on skill of workers. The knowledge is passed down to younger workers
through an apprenticeship system and on-the-job learning.
Scaffolding is usually subjected to a wide range of loading during assemblage,
use and dismantling. It should support its own dead load, live loads from
construction materials, workers and tools, dynamic loads from material
placement and wind loads.
9
When failures occur, large areas of scaffolding can suddenly collapse. Scaffolds
can collapse because of poor construction or misuse leading to them being
loaded beyond their safe capacity to support the load. Scaffolding stability
depends on carefully following the manufacturer’s instructions and national
regulations. And also rough weather conditions can damage the scaffolding
quite severe. Figure 5 shows the scaffolding failure in San Francisco caused by
unforeseen heavy winds.
Figure 5 Scaffolding failure in San Francisco caused by stormy winds
Dismantling is the most difficult and hazardous operation in scaffolding
business. The work should be planned carefully so that the scaffolding remains
stable, workers are prevented from falling from the scaffold and others are
protected from the risk of falling materials. Dismantling can place large loads on
the scaffold unless the work is planned to keep the amount of material stored on
the scaffolding to a minimum. Sometimes it should be additionally strengthened
and stabilized by providing extra elements (Health and Safety Authority of
Ireland 2008, p. 78).
Scaffolding has a variety of applications. It offers a safer and more comfortable
work arrangement compared to leaning over edges, stretching overhead and
working from ladders. Properly assembled and maintained, scaffolding provides
workers safe access to work locations, stable working platforms, and temporary
storage for tools and materials for performing immediate tasks (N.C.
Department of Labor. Occupational Safety and Health Division 2008, p. 1).
10
3 BASIC SCAFFOLDING TERMS
The key elements of the scaffolding are standards, ledgers and transoms. The
standards are the vertical tubes that transfer the entire mass of the scaffolding
to the ground where they rest on a base plate to spread the load. Usually
instead of the simple base plate there is an adjustable base jack to level the
scaffolding on uneven surface. Ledgers (Runners) are horizontal members in
the direction of the larger dimension of scaffolding. Transoms (Bearers) are
horizontal members in the direction of smaller dimension. They usually provide
the support for decks and sometimes called bearers. Diagonal braces bring
rigidity to the scaffolding structure. All these main elements are shown on
Figure 6 below.
Transom (Bearer)
Modular joint
Ledger (Runner)
Standard
Diagonal braces
Base jack
Figure 6 Main elements of scaffolding
On the image above the modular Ring-Lock joint is presented. The joints used
to attach the tubes together vary greatly between different types of scaffolding.
They will be described in detail further.
11
Basic scaffold dimensioning terms are explained on Figure 7. No decks, bracing
or joints shown.
Bay Length
Width
Lift
Height
Figure 7 Scaffolding dimensioning terms
Figure 8 shows the protection of a working platform.
Guardrails
Decking level
Toe-board
Guardrail
Height
Figure 8 Guardrails and toe-boards
Toe-boards are needed to prevent tools or other things from falling over the side
and striking someone beneath the scaffolds.
12
4 MAIN TYPES OF SCAFFOLDING SYSTEMS
4.1
Modular scaffolding
4.1.1 Introduction to modular scaffolding
Ideally, a scaffolding system has to be very flexible and fast to assemble. It
must be erected quickly and efficiently.
Modular scaffolding is the most advanced type of scaffolding system. Being the
common choice in Europe for complicated industrial structures and intricate
facades it was chosen as the main subject of study in the present Thesis work.
Modular scaffolding provides enough versatility and reduces the time of
assembly, compared to non-modular systems. High rigidity of joints gives more
load-bearing capacity and height. Modular systems consist of standards with
fixed connection points that accept ledgers, transoms, and diagonals that can
be interconnected at predetermined (modular) levels.
All the main components of modular scaffolding, such as standards, ledgers,
transoms, decks and diagonals, have uniform lengths and widths. The variety of
choices is quite wide and that allows lots of adjustments to be made to suit any
particular project. The versatility is very close to «Tube-and-Clamp» system.
At the same time utilizing standard hand-tools, modular system is fast-up and
fast-down, minimizing labour costs and delays. This can be considered as the
main advantage.
With its high versatility and fast assembly the modular scaffolding is especially
suited for applications in industry, power stations, shipyards and special
structures. But of course, it is also possible to provide façade scaffolding as well
if the fast assembly and good versatility is needed.
13
4.1.2 Cup-Lock modular scaffolding system
The Cup-Lock modular system is a multi-purpose system which features the
connection which allows up to 4 horizontal members to be connected to vertical
member in one single clamping action without using of nuts, bolts or wedges.
The locking device, formed by two cups, makes the Cup-Lock very fast, easy
and versatile scaffolding system.
The typical Cup-Lock modular scaffolding joint principle is shown on Figure 9.
Upper Cup
Steel Blades
Bottom Cup
Figure 9 Cup-Lock joint principle
The Bottom Cup is welded to vertical tube and a movable Upper Cup is free to
move up and down. Cups are made of different materials. Welded Bottom Cups
are usually pressed from high quality steel, while the Upper Cups are made out
of softer, forgeable casting. Horizontals or diagonals are usually made of
48,3mm steel tubes with special forged Steel Blades at the ends. The blades
are placed into the Bottom Cup and locked in place with the Upper Cup, which
is tightened by a hammer blow. This provides the firm grip, making the
connection rigid and ready to endure rough building site handling.
14
4.1.3 Ring-Lock modular scaffolding system
The Ring-Lock Modular System is the most advanced scaffolding system on the
market. It assembles quickly and easily, at the same time providing enough
versatility to any building configuration. The centrepiece of the Ring-Lock
System is the Ring-Lock itself, which is also called Rosette Connector. The
horizontals and diagonals have special Wedge Heads with captive wedges.
The stages of wedge driving are shown on Figure 10.
Figure 10 Wedge driving stages of Ring-Lock modular scaffolding system
Sliding the wedge head over the Ring-Lock and inserting the wedge into the
opening immediately secures the component. There is still sufficient movements
available needed to secure the other end of the ledger. Hammer is the only tool
required for complete assembly. A hammer blow to the wedge transforms the
loose connection into a strong structurally rigid one. As the wedge is driven, it is
locked securely from any movement. Figure 11 shows the assembled joint.
Wedge Head
Wedge
Ring-Lock
Openings
Figure 11 Ring-Lock joint principle
15
The working principle of Ring-Lock System is similar to the Cup-Lock System,
but the difference is the increased rigidity of the connections. The flat design
of the Ring-Lock is also helps to prevent from clogging the joint with dirt of
whatever type.
There are 8 punched-out openings in the Ring-Lock. It is usually so, that 4 of
them are the small ones, which automatically centre the ledgers at right angles.
The other four openings are wider, which permit the alignment of ledgers and
diagonal braces at the required angles. The design of the openings varies
between the Ring-Locks from different manufacturers. It may be so that all the
openings are of the same size. Figure 12 shows possible angle adjustments.
Figure 12 Angle adjustment scheme
It is obvious that the angle can be changed from 45º only if there is no adjacent
element installed. And if the angle is changed than the adjacent narrow opening
is blocked.
The Ring-Locks are commonly provided at the vertical members at a distance of
0,5 m. The ledgers and transoms have modular dimensions and the lengths of
16
diagonals are designed according to bay length and installation height.
Exemplary element variety of the Ring-Lock modular system is shown on Figure
13. The principle is the same for any modular system.
Ring-Locks
Installation height
Transoms
Bay length
Diagonal
Ledgers
Figure 13 Ledgers, transoms and diagonals in different lengths
Thus, the modular systems can be easily adjusted to the most complex layouts.
Also it is necessary to mention the important element called «starter». It is
shown on Figure 14.
Figure 14 Starter element
Starter is fixed on an adjustable base jack. It facilitates the horizontal alignment
and gives the possibility of racking of standards by the only one person.
17
4.2
Tube-and-Coupler scaffolding
«Tube-and-Coupler» (also called «Tube-and-Clamp») is a type of scaffolding
consisted of tubes and couplers.
The main advantage of the tube-and-coupler scaffold is that horizontal tubes
with walking decks can be placed at any height of vertical tubes. At the same
time vertical tubes can be spaced at any distance apart. Maximum distances
are restricted only by engineering constraints.
«Tube-and-Coupler» scaffolding requires a lot of labour input for assembly,
because it is not a modular system. Generally it is used for work on nonrectangular, curved and irregular shaped structures, where unlimited versatility
is needed.
This type of scaffold is very popular in North American nuclear power plants.
Vertical tubes are connected to horizontal with Right Angle Rigid Couplers.
These couplers are shown on Figure 15.
Figure 15 Tubes connected with Right Angle Rigid Couplers
It is obvious that rigid couplers do not allow rotation of elements. They can be
connected only with right angles.
18
Diagonal tubes which are used to stabilize scaffold are connected with Swivel
Couplers. These couplers are shown on Figure 16.
Figure 16 Tubes connected with Swivel Couplers
On the images above the tubes are painted, while the couplers are hot-dip
galvanized. Figure 17 shows common «Tube-and-Coupler» scaffolding. It is
noticeable that transoms, which bear decks, are connected to standards on
higher than longitudinal ledgers. It is done so to ensure that if the coupler that
holds bearing transom fails or slips down it will find a support on the ledger.
Figure 17 «Tube-and-Coupler» scaffolding
«Tube-and-Coupler» is for sure the most versatile scaffolding system on the
market. With movable couplers it is possible to adjust the system to any
conditions, creating different distances between the elements. The problem is
that the rigidity of coupler joints might be insufficient and also the labour input
which is needed for assembly is too high.
19
4.3
Fabricated frame scaffolding
Fabricated
frame
scaffolding
(also
called
Tubular
welded
frame
scaffolding) features manufactured welded frames made in various heights
and widths. The principal scheme is shown on Figure 18.
Fabricated Frames
Braces
Figure 18 Principal scheme of tubular welded frame scaffolding
Frames are supported by cross, horizontal or diagonal braces, or a mixture of
braces, to stabilize vertical members and to insure the rigidness of the whole
scaffolding system. Brace connections must be securely fastened.
Figure 19 below shows the most advanced and quick brace-fastening system,
which is now used by many scaffolding manufacturers.
Figure 19 Modern way of fastening the braces
20
Older frame scaffolding systems featured locking pins, welded to the frames.
Such pins also allow to connect braces and to secure them without using any
special tools. The main principle is shown on Figure 20.
Closed
Open
Figure 20 Locking pin work principle
In any system the braces have a fixed length that automatically squares and
vertically aligns vertical members so that the erected scaffold is always square
and rigid. The scaffold is extended by adding braces and frames until the
desired length is reached. Scaffold height is increased by stacking end frames
on top of each other. The bottoms of the legs of the upper end frames slide into
the tops of the legs of the lower end frames and are joined together with
coupling pins.
Compared with «Tube-and-Clamp» system the fabricated frame scaffolding is
much easier and faster to assemble, but its versatility is many times lower. It is
not easy to repeat a complicated shape with this system.
21
4.4
Mobile scaffolding
Mobile scaffolding is a powered or non-powered portable caster or wheelmounted scaffolding. It can be constructed of any components: tube and
coupler, fabricated frames or modular elements and must conform to design,
construction and loading requirements for those scaffolding systems. The
scaffolds must be braced by cross, horizontal or diagonal braces, or
combination thereof, to prevent buckling or collapse. (N.C. Department of
Labor. Occupational Safety and Health Division 2008, p. 23)
On Figure 21 below it is shown the mobile scaffold, assembled from fabricated
frames and braced by cross braces.
Access gate
Work platform
Cross-bracing
Locking
casters
Access ladder
Figure 21 Fabricated frame mobile scaffolding
22
Caster and wheel stems are pinned or otherwise secured in scaffold legs. While
in a stationary position, casters and wheels must be locked with a positive
wheel and/or wheel and swivel locks, or equivalent means, to prevent
movement.
When manual force is used to move the mobile scaffold, the force should be
applied as close to the base as practicable.
Figure 22 shows the mobile scaffold gantry for the installation of tunnel sheet
membrane and concrete lining steel reinforcement at the Brisbane Airport Link,
Australia's largest road infrastructure project.
Figure 22 Modular mobile scaffold gantry in the tunnel, Australia
Two access gantries were assembled on electric driven steel frame wheel
bogies travelling on rails. Scaffold gantries where decided to be most desirable
as they provide the greatest flexibility for modification with expected tunnel
profile changes. (Layher GmbH & Co. KG. Australian website).
23
5 MAIN RUSSIAN MANUFACTURERS OF MODULAR
SCAFFOLDING SYSTEMS
5.1
RINSTROY Ltd.
RINSTROY Ltd. is a huge manufacturer of building equipment. It produces
scaffolding systems up to 100 metres in height, formwork, ladders, protection
nets, cover materials, concrete mixers and other different equipment.
Scaffolding systems made by RINSTROY are fixed-frame, tube and clamp, and
the most advanced Modular Ring-Lock system.
Modular Ring-Lock system allows usage of scaffolding in the projects of any
complexity level.
Innovative detail, which distinguishes modular scaffolding made by RINSTROY
from the other manufacturers, is that they use plastic deformation in production
of vertical standards (Figure 23).
Figure 23 Plastic deformation of the ending of vertical standard by RINSTROY
24
No welding is used to attach the Ring-Lock/Rosette to the tube. It is shown on
Figure 24 below.
Figure 24 Ring-Lock by RINSTROY, secured on tube by plastic deformation
Such connection provides increased stiffness and stability compared to spigot
fitting assembled by putting the tube of less diameter into the vertical standard,
like described on Figure 25 and 26 below.
Figure 25 Common spigot fitting with an additional inner tube
25
Figure 26 Common spigot fitting with additional screwed inner tube and welded
Ring-Lock
Below is the table of main characteristics of Ring-Lock scaffolding system by
RINSTROY (Table 1).
Table 1 Main characteristics of the scaffolding system by RINSTROY
Tube diameter
48 mm
Maximum height
up to 100 m
Lift height
2,0 m
Scaffolding width
1,0 m
Bay length
Max load applied to the deck,
kg/m2
1,0 m
2,0 m
2,5 m
3,0 m
350
300
250
200
There is the only choice of scaffolding width mentioned because of the wooden
decks which are 1,17x0,95m and lay upon the longitudinal ledgers. No other
types of decks available from RINSTROY. Load-bearing capacity is taken from
the manufacturers manuals and like it is told there it depends on the bay length
(distance between the standards along the facade).
Vertical distance between the Ring-Locks is normally 1m, but 0,5m can be
made by special order. All the elements are painted in company’s black and
orange colours.
26
5.2
MDN-Prom Ltd.
MDN-Prom Ltd. produces all types of scaffolding systems, which are in common
use on Russian construction sites: fixed frame, tube and clamp and ring-lock
scaffolds. Production factories are located in two cities – Serpuhov and Unecha.
The most advanced systems are Modular Ring-Lock Scaffolding LSK-60 and
LSK-100, suitable for all the works up to 60m and 100m in height. Difference
between these two types is in the wall thickness of tubular vertical standards,
which is 2mm for LSK-60 and 3mm for LSK-100.
Vertical standards are done in a common way – Ring-Lock is secured by
welding (Figure 27). No plastic deformation is used here, like they do it in
RINSTROY. Spigot fitting provides connection of vertical standards (Figure 28).
Figure 27 Vertical standards with welded Ring-Locks by MDN-Prom
Figure 28 Spigot connection of standard
27
Previously, MDN-Prom was manufacturing the joint that allowed attaching only
four elements simultaneously. The sizes of wedge heads were way too big to
put diagonals next to ledgers. Left image on Figure 29 clearly shows this.
Figure 29 Development of Ring-Lock joint by MDN-Prom
Last year the company redesigned the wedge heads making them smaller (right
image on Figure 29), so that now all the 8 elements can be connected to the
Ring-Lock at the same time. This small improvement considerably increases the
versatility of the whole system. Below is the table of characteristics of Ring-Lock
Scaffolding by MDN-Prom 9 (Table 2).
Table 2 Main characteristics of the scaffolding system by MDN-Prom
LSK-60
LSK-100
Tube diameter, mm
48 mm
Tube wall thickness, mm
2 mm
3 mm
Maximum height, m
60 m
100 m
Lift height, m
2,0 m ; 3,0 m
Bay length, m
1,0 m ; 1,2 m ; 1,5 m ; 2,0 m ; 3,0 m
Scaffolding width, m
Max load applied to the wooden
decks, kg/m2
1,0 m
1,2 m
1,5 m
2,0 m
3,0 m
270
225
180
135
90
Max load applied to the metal
decks with strengthened
ledgers, kg/m2
500
28
Like RINSTROY, MDN-Prom normally equips its scaffolding with wooden
decks. However, they can offer longer, than common square 1x1m decks. The
load-bearing capacity in this case decreases while increasing the width,
because the wooden decks are meant for resting upon the longitudinal ledgers.
It is shown on Figure 30 below.
Figure 30 Wooden decks laying upon the longitudinal ledgers
To increase the maximum load supported it is possible to use special horizontal
elements, trusses-like, with long metal decks. They are shown on Figure 31.
Figure 31 Strengthened horizontal element and long metal deck
By doing so the load-bearing capacity of LSK scaffolding reaches its maximum
of 500 kg/m2. Thus the scaffolding system becomes suitable for doing
brickwork.
All the scaffolding elements by MDN-Prom are painted.
29
5.3
Monolit Stroy Komplekt Ltd. (MSK)
Monolit Stroy Komplekt Ltd. (MSK) specializes in manufacturing steel
constructions. Huge part of their produce belongs to scaffolding. Systems they
offer are «tube and clamp» and modular Ring-Lock system.
MSK divides their Ring-Lock system into two types – professional and light
weighted. Professional consists of the tubes 60 mm in diameter and can reach
up to 100 m in height, while light weighted features common 48 mm thick tubes.
Ring-Lock is secured on the standard by welding. The Ring-Lock itself provides
the possibility of immediate connection of 8 horizontal elements: ledgers,
transoms and cross bracers. The joint is shown on Figure 32 below.
Figure 32 Ring-Lock joint by MSK
Table 3 Main characteristics of the scaffolding system by MSK
Tube diameter
60 mm
48 mm
Maximum height
up to 100 m
up to 80 m
Lift height
2,0 m
2,0 m
Scaffolding width
1,0 m
1,0 m
3,0
3,0
200
200
Bay length
Max load applied to the deck, kg/m
2
All the tubes are painted red using powder method.
30
5.4
SIMAN+ Ltd.
SIMAN+ Ltd. was established in 2003. The main specialization of the company
is production of different scaffolding types.
Systems, which are being produced by SIMAN+, are common Fabricated
Frame Scaffolding and Modular Ring-Lock System. The Ring-Lock in the
modular system was quite similar to other companies, featuring the same kinds
of openings in rosette, allowing to attach up to 8 elements simultaneously.
Normally their scaffolding is equipped with simple squared wooden decking
(which restricts the width to be no more than 1m) like previously mentioned
manufacturers. But as well as with MDN-Prom it is possible to order from
SIMAN+ the metal decks along with strengthened horizontal elements to reach
the maximum load bearing capacity of 600 kg/m2. It is the highest among all the
manufacturers described.
Table 4 Main characteristics of the scaffolding system by SIMAN+
Tube diameter, mm
48
Maximum height, m
80
Lift height, m
2,0
Bay length, m
1,0
2,0
Max load applied to the deck, kg/m2
200
Max load applied to the metal decks
when using strengthened ledgers,
kg/m2
600
3,0
In the year of 2005 SIMAN+ invented its own type of joint that allows connection
of elements to vertical standard at any angle. This joint was designed to be
used when making scaffolding for buildings and structures of complicated or
spherical shapes. The main principle of this joint is explained on Figure 33
below.
31
Grip
Cone
Pin
Hole
Cup
Figure 33 Patented joint by SIMAN+
The joint consists of Bearing ring or Cup, Grip and the Cone. Bearing Ring
looks like a cup with thickened walls and plate-like bottom that is secured on the
vertical standard. Bearing ring is shown on Figure 34.
Figure 34 Bearing ring / Cup
It is noticeable that the bearing ring has a small cutting out in its inner circle. A
pin on the cone is being inserted into it, which prevents rotation.
Special grips are the necessary parts of each horizontal or diagonal. Inner
surface of the grip retraces the surface of the cup wall while the outer surface
retraces the cone. The grips are fully casted. One is shown on Figure 35.
32
Figure 35 Grip
During the assembly process the grips are put onto the bearing ring and then
jammed by the cone with hammer blows applied. Cone itself is located on the
vertical and freely moves up and down. In its bottom part it has a locking pin,
which goes into the hole in the cup (Figure 36) and, like it was told above,
secures the cone from rotation. The pin is 2 centimetres long. It is enough to
ensure that the cone is not moving.
Figure 36 Cone with a locking pin
Hammer blowing begins after inserting the locking pin into the hole in the cup.
The cone then goes deeper and jams the grips. The joint becomes rigid.
This joint has no analogues in Russia. It is the patented system, which belongs
to SIMAN+. It can bear more load than the common Ring-Lock and is very
flexible, but it is not much used and being produced only by special orders. The
33
reason for this is that in most cases the versatility of the Ring-Lock joint is
enough. And with the cup and the cone instead of rosette the joint becomes
heavier than the simple Ring-Lock. It is its main weak point
SIMAN+ produces one more joint, which is called the «Star» (Figure 37). New
connection features 8 narrow openings to attach the elements. It replaced the
disc-like rosette that had been manufactured earlier.
Figure 37 «Star» joint by SIMAN+
Manufacturer states that the main reason for replacing 4 narrow and 4 wide
openings with 8 narrow ones is the increased precision of assembly. They think
that the scaffolding becomes more safe if all the elements are attached to the
narrow openings, especially shaped for rigid connection. On Figure 38 below
there are eight grips shown, connected simultaneously to the same star.
Figure 38 Connection of elements to the «Star» joint
34
So in SIMAN+ they decided to sacrifice the possibility of adjusting the angle,
gaining more secure connection of elements. One more advantage of the «star»
is the weight reduction, compared to disc-like Ring-Lock.
Like the other Russian manufacturers in SIMAN+ they apply paint coating to
their elements using the powder method.
6 COMPARATIVE ANALYSIS OF RUSSIAN RING-LOCK
SCAFFOLDING SYSTEMS
Systems described above are the most widely used ones produced in Russia.
The Ring-Lock type scaffolding itself is not so widely used as simpler «Tubeand-Clamp» system or the scaffolding made of fabricated ready-made frames.
The reasons for that are the following. The Ring-Lock type scaffolding gives
sufficient versatility together with high load bearing capacity. But often happens
so that there is no need to bear heavy loads or to provide big heights. In
addition to it, if the shape of facade is very complicated then «Tube-and-Clamp»
system wins, providing the highest versatility available for scaffolding. Also it is
quite usual situation that the shape of façade is so plain and simple that it is
much easier to construct the scaffolding from ready-made frames.
Russian scaffolding comes with paint finish only. There are no manufacturers
who offer hot-dip galvanized elements. Painted scaffolding is cheaper, but less
durable.
All Ring-Lock systems described above possess their own load-bearing
capacities. According to manufacturer’s manuals it varies dependable on bay
length or width. The main figures are listed in the table 5.
35
Table 5 Load-bearing capacities of Russian scaffolding systems
System by
1,0m
1,2m
1,5m
2,0m
2,5m
3,0m
350
-
-
300
250
200
-
-
-
-
-
200
SIMAN+
200
-
-
200
-
200
+ strengthened elements
600
System by
1,0m
1,2m
1,5m
2,0m
2,5m
3,0m
270
225
180
135
-
90
-
-
-
500
-
500
Bay length
RINSTROY
MSK
Width
MDN-Prom
+ strengthened elements
600
600
Width of the scaffolding is very important parameter. Bigger variety of widths
available – more versatile is the scaffolding. It is so, because different kinds of
works require different amount of space.
Table 6 Widths of scaffolding available from Russian manufacturers
System by
Width
1,0m
RINSTROY

MDN-Prom

1,2m
1,5m
2,0m
3,0m








+ truss-like transoms
MSK

SIMAN+

It is obvious from the table that the only two manufacturers, MDN-Prom and
SIMAN+, offer quite good variety of widths for its scaffolding.
Like it was mentioned previously RINSTROY Ltd. manufacturers very modern
Ring-Lock joint and uses plastic deformation to make the spigot fitting needed
for connection of the vertical standards. Also the Ring-Lock itself is not welded
to the tube, but firmly secured using the same method. The company claims
that when using the welding it might happen so that it is done not very precise
and the durability of the joint is decreased.
36
Featuring such an up-to-date system, the RINSTROY scaffolding possesses
very low versatility regarding to the only one choice of width – one metre. The
company manager answers that it is so, because they are using the standard
wooden decks, which are squared and can be only 1m in width. They lay upon
the longitudinal ledgers. That is why the width can be only 1 metre. It is shown
on Figure 39 below. And there is no possibility to make a special order for
another kind of decks.
1m
Squared wooden deck laying upon
the longitudinal ledgers
Figure 39 Scaffolding by Rinstroy. Wooden decking.
The same situation is with the scaffolding systems by MSK. The width can be
only 1 metre like from RINSTROY. MSK, however, is the least versatile system
between all of them, offering the only one choice of bay length – 3 metres.
It is a very common problem with Russian scaffolding systems that they are so
narrow. While possessing the advantage of modular systems to be of any width,
it is not used completely, because of the narrow decking.
37
SIMAN+ featuring innovative patented joints offers the choice of three bay
lengths, and three widths. The width is not limited to one metre, because they
offer not only squared wooden decks, but long metal ones also (Figure 40).
Figure 40 Metal scaffolding deck
Long metal decks lay upon the transversal transoms. In this case the width is
limited only with the length of the transom available.
Biggest variety of elements is available in the scaffolding system LSK by MDNProm. Scaffolding width as well as the bay length can be 1,0 ; 1,2 ; 1,5 ; 2,0 ;
3,0 metres. The decks are squared wooden ones or metal modular decks 2,0
and 3,0 metres in length. Not a long time ago they also updated their Ring-Lock
disc, making it so that all the eight elements are ready to be connected at once.
LSK system by MDN-Prom and system by SIMAN+ can bear the heaviest loads
among the other competitors. The maximum distributed load can be up to 500
kg/m² with LSK and 600 kg/m² with the system by SIMAN+. Manufacturers state
that this load-bearing capacity can be achieved by using the strengthened
horizontal elements along with metal decking.
But LSK scaffolding by MDN-Prom has a weak point in the wedge heads,
compared to ones, produced by other Russian manufacturers. The wedge head
is not made of fully casted steel, but welded from two parts. That makes it
possible for some defects to appear in the welding seam and reduce its
strength. The wedge heads by RINSTROY, SIMAN+ and MSK are fully casted.
The difference is visible on Figure 41.
38
Two parts
Fully casted wedge heads
Figure 41 Wedge head by MDN-Prom (left) and fully casted wedge heads by
RINSTROY, SIMAN+ and MSK (right)
Summarizing the advantages and disadvantages of each scaffolding system I
think that the SIMAN+ is the best manufacturer among the others. The
company pays great attention to development of their scaffolding, introducing
new ideas and having their own view of the ideal joint. Offering the choice
between three bay lengths and three widths makes their system quite flexible
and ready to be used not only for facade works but for more complicated tasks
as well. Moreover, with strengthened horizontal elements and metal decking it is
possible to achieve the maximum load-bearing capacity up to 500 kg/m². The
company is ready to consider any wish of the customer and respond according
to the goals defined.
7 COMPARISON OF RUSSIAN SCAFFOLDING SYSTEMS WITH
THE ONES COMMONLY USED IN FINLAND
There are no Finnish scaffolding manufacturers and the systems used on the
construction sites and industrial objects in Finland are in most cases Germanmade. The most popular are Ring-Lock systems by Alfix, Layher, Peri and
Plettac. All these systems are quite similar by principle of work and materials
used. For the comparison Alfix Module II Plus scaffolding system was chosen.
The main disadvantage of the Russian Ring-Lock scaffolding systems is a poor
variety of elements available. Being modular, there is a need for good catalogue
39
of elements to choose from. This fact leads to very low versatility, compared to
German scaffolds.
For example, the bay lengths available from the MDN-Prom are 1,0 m ; 1,2 m ;
1,5 m ; 2,0 m ; 3,0 m. Five different lengths of tubes. And two strengthened
transoms 2,0 and 3,0 metres in length to carry the higher loads. And it is the
richest choice between all the manufacturers. On the other hand, German Alfix
offers 13 tube lengths from 0,36 to 4,14 metres. Moreover, there are also
reinforced and double-tube ledgers and transoms available. Transoms can be
U-shaped, which is needed to carry different kinds of decks (Alfix Scaffolding
System Modul PLUS II Catalogue). The variety is shown on Figure 42. Figure
43 illustrates special U-shaped transom.
Tube ledger
Tube ledger, reinforced
Double tube ledger
U-transom
U-transom, reinforced
Figure 42 Different types of ledgers and transoms by Alfix
Figure 43 Deck carried by U-shaped transom
40
The Ring-Lock joints themselves are quite similar (Figure 44). European
manufacturers, and Alfix among them, prefer to manufacture it as a disk with 8
openings – 4 of them are the small ones, which centre the ledgers at right
angles. The other 4 openings are wider, which permit to vary the angle. RingLocks by RINSTROY and MSK are done the same. The Ring-Lock disk by
MDN-Prom and the star by SIMAN+, however, feature 8 small openings,
sacrificing the possibility to adjust the angle, but keeping the assembly process
more precise.
Figure 44 Ring-Locks from left to right: Alfix, RINSTROY, MDN-Prom, SIMAN+
It is quite difficult to tell if it is better to keep all the opening small or not.
SIMAN+ had been manufacturing the same Ring-Lock like Alfix or RINSTROY
before they went to the star connection. When they were asked about the
reason for that, it was told that the star is more reliable and at the same time
more lightweight. There is no possibility for elements to get loose or to move
inside the narrow slot. That is the reason they stated.
The diameter of tubes used for scaffolding is the same for Russian
manufacturers and for Alfix, being 48 mm with wall thickness of 3 mm. But the
finish is different. While all the Russian manufacturers paint their tubes,
German-made scaffolding elements are always hot-dip galvanized. It makes
them be more rust-resistant and long-lasting.
The wedge heads by Russian manufacturers and by Alfix are made similarly
from fully casted steel. Only the wedge head by MDN-Prom is quite outdated,
being welded from separate details, like it was told in the previous chapter.
Figure 45 below shows the casted wedge heads by Alfix and SIMAN+.
41
Narrowed to be
inserted into the
tube and welded
Figure 45 Wedge heads by Alfix (left) and SIMAN+ (right)
Another fact about Russian scaffolding is that while possessing good
engineered joints their capacity cannot be used entirely, because of the wooden
decks that are not able to carry loads higher than 200 kg/m2 on average or the
lack of strengthened elements. Only two of four manufacturers described
earlier, which are MDN-Prom and SIMAN+, can provide the load bearing
capacity up to 500 and 600 kg/m 2, respectively, by using metal decking with
strengthened ledgers. German Alfix offers the choice between different decks of
various load bearing capacities with a maximum of 600 kg/m2. Reinforced and
double-tube ledgers and U-transoms are ready to complete the high load
bearing system. One more problem with wooden decks is that they are usually
not compliant with fire-safety demands when the scaffolding is assembled at a
hazardous industrial object such as an oil refinery.
It is obvious that German scaffolding is more advanced compared to Russian,
providing wider variety of elements, better finish and more complete technical
documentation. But manufacturers in Russia are constantly improving their
products. Some companies, like RINSTROY or SIMAN+, develop their own
types of joints. Scaffolds by MDN-Prom and SIMAN+ are quite versatile and can
possess the load-bearing capacity comparable to German systems. And the
price of Russian-made scaffolding is much lower – up to two or three times.
That is the main reason why German systems are not so widely-spread on
Russian construction sites.
42
8 RUSSIAN REGULATORY DEMANDS FOR SCAFFOLDING
8.1
Introduction to Russian standardization system
Russian standardization system underwent significant changes in the end of
2002 year. Federal Law №184 from 27th of December 2002 brought the idea of
documents called literally «Technical Regulations». They were supposed to
replace the existed standardization system that consisted of regulation
documents, called GOST standards (an acronym for GOsudarstvennyy
STandart, which means «state standard») and SNiP (Stroitelnye Normy i
Pravila, which means «construction norms and regulations») . The usage of the
old norms became voluntary. «Technical Regulations» on the other hand are
mandatory, but they set only minimal requirements concerning the safety. It was
planned so that only the safety questions should be regulated.
For example, Technical Regulation «On safety of buildings and structures»
states that the structure must be designed and built so that while human being
stays inside no harmful effect to his health occurs. And it provides no direct
instructions for how to actually do this.
It is impossible to calculate or design according only to «Technical
Regulations». That is why all the «Technical Regulations» have in their
appendices the lists of old regulation documents. Designing according to them,
like it is told, provides the fulfilment of demands, mentioned in «Technical
Regulations». There are two of these lists in «Technical Regulations» for
structures. One is mandatory, and another one is voluntary. Mandatory list
should be considered in any way. Voluntary one is for reference only, but it is
meant to help in fulfilling the demands of «Technical Regulations».
To the construction industry Federal Law №384 from 30th of December 2009
brought already mentioned document called Technical Regulation «On safety
of buildings and structures». It took effect from 1 of July 2010. Like it was told
above it featured two lists of old regulation documents – mandatory and
43
voluntary ones. It was mentioned also that other «Technical Regulations»
cannot contradict the Technical Regulation «On safety of buildings and
structures». Also from the text of Federal Law №384 it follows that the old
regulation documents in the lists from Technical Regulations have to be
updated due to 1st of July 2012.
Not much really changed, but now it is not obligatory to design according to old
SNiPs and GOSTs that are not mentioned in the mandatory list. If the task is
different then it is allowed to do whatever taking into account only the safety
demands of «Technical Regulations».
Concerning the scaffolding systems, Technical Regulation «On safety of
buildings and structures» contains a reference to SNiP 12-03-2001 «Work
safety in construction. Part 1. General requirements. Chapter 7.4.1-7.4.40».
There are some requirements for usage of scaffolding systems that must be
followed.
Two more regulation documents that deal with scaffoldings are: POT R M-0122000 «Intersectoral Work at Height Safety Rules» and RD 34.03.204 «Safety
Rules for Works with Tools and Devices». They contain quite similar information
and it is a little bit wider than in SNiP 12-03-2001.
In the voluntary list of regulation documents from Technical Regulation «On
safety of buildings and structures» there is also one about scaffolds, called
GOST 27321-87 «Demountable tubular scaffold for constructional work». This
document is mostly for manufacturers and it deals only with two types of
scaffolding systems: «tube and coupler» and very old «pinned» type.
Federal Law in Draft №192544-5 called Technical Regulation «On safety of
building materials, products and constructions» is adopted at the first
reading. The final list of constructions that will be subject to this regulation is in
the stage of development and quite short now. Scaffolding systems are not
mentioned yet. Time will show if they appear there or not.
44
One more thing to mention is that while there are GOSTs and SNIPs, which are
not in the mandatory list of Technical Regulation «On safety of buildings and
structures», some of them may still be in power. It can happen in cases when
they are referenced from other normative documents. So it is important to check
this all the time.
POT R M-012-2000 «Intersectoral Work at Height Safety Rules» is generally
very independent document that deals with safety during any works at height in
construction, industry and other fields. Its status cannot be lowered by
Technical Regulation.
Chapter 2.2.2 of POT R M-012-2000 says that scaffolds have to comply with
requirements of two GOSTs: GOST 24258-88 «Different types of scaffolding.
General specifications» and GOST 27321-87 «Demountable tubular scaffold for
constructional work. Specifications».
GOST 27321-87 was mentioned previously as the one from the voluntary list of
Technical Regulation. It contains information only about «tube and coupler» and
«pinned» systems. But the first one - GOST 24258-88 deals with all types of
scaffolding and contains general requirements for any system.
Being referred to in the active document means that the content of these
GOSTs has to be followed. Generally, rules given in GOST 24258-88 are quite
similar to ones in POT R M-012-2000 and they do not contradict each other.
Taking into account that this GOST is quite old it is still active though. In
addition to general requirements it gives valuable information about the
documentation. In its appendices there is a strict form of scaffolding passport
that must be provided by manufacturer. And also there is a form of «Journal of
scaffold accounting». In POT R M-012-2000 it is called «Journal of acceptance
and visual examination of scaffolding», but generally it is the same. Concerning
that POT R M-012-2000 is more up-to-date document, the term «Journal of
acceptance and visual examination of scaffolding» is widely used right now.
The common form of the journal is presented in the Appendix 2.
45
8.2
Documents to carry about when performing assembly of scaffolding
When using the scaffolding, some special documentation has to be prepared,
according to present regulation system. These documents are listed below.
1. Order, which assigns a committee responsible for acceptance of scaffolding.
Copies of the order are kept by the director of works and at the work safety
service.
2. Handover certificate
And adequate handover procedure for transferring control of the scaffold from
the erector to the user is an important part of managing scaffolding safety. Both
the scaffold erector and the user should be satisfied that the scaffold can
provide a safe working platform and can carry the designed loads safely.
Scaffolding that is more than 4 m in height can be used only after it is accepted
by committee, assigned by a person, responsible for work safety in a company
(or general director himself) and after preparing a handover certificate. (SNiP
12-03-2001, § 7.4.14; POT R M-012-2000, § 2.2.40).
If scaffolding is assembled by subcontractor for its own use, then it is accepted
by the committee assigned by the director of this subcontracting company or
their site manager. In this case the committee is headed by the engineering
worker from the same subcontracting company. (RD 34.03.204, § 5.2.20).
If scaffolding is assembled by energy enterprise (energy industry) itself or it is
assembled by subcontracting company (that performs repairs, construction
works or any other) for the needs of energy enterprise then the scaffolding is
accepted by the committee assigned by the order inside the energy enterprise.
It is headed by the engineering worker from the same energy enterprise. There
are also representatives from every subcontracting company, workers from
which will be using this scaffolding. (RD 34.03.204, § 5.2.20).
46
The handover certificate is approved by the head engineer (technical director)
of the company that performs the acceptance. (POT R M-012-2000, § 2.2.39;
RD 34.03.204, § 5.2.20).
When scaffolding is assembled by subcontractor to meet its own needs it is
acceptable if the handover certificate is approved by subcontractor’s site
manager. (POT R M-012-2000, § 2.2.39; RD 34.03.204, § 5.2.20).
The main point here is that the person who approves the handover certificate
cannot be a member of the committee.
During the acceptance of scaffolding it is checked that all the braces and
connections that provide stability are in their places, decks and guard-rails are
not broken, standards are vertical, supporting platforms are stable and there is
a grounding made for metal scaffolding. (SNiP 12-03-2001 § 7.4.14; POT R M012-2000, § 2.2.40; RD 34.03.204, § 5.2.21).
Before the approval of the handover certificate it is forbidden to use the
scaffolding (POT R M-012-2000, § 2.2.39; RD 34.03.204, § 5.2.20). The
common form of the scaffolding handover certificate is presented in the
Appendix 3.
3. Journal of acceptance and visual examination of scaffolding.
Scaffolding that is below 4 m in height can be used right after it is accepted by
superintendent or foreman with the note put into the journal of acceptance and
visual examination of scaffolding (SNiP 12-03-2001 § 7.4.14; POT R M-0122000, § 2.2.40; RD 34.03.204, § 5.2.21). If the scaffolding is more than 4 m in
height then, like it was told above, handover certificate issued by the committee
is required.
In building organisations all the scaffolds have to be visually examined every
day right before use by the brigade leader who is going to use the exact
scaffolding and no less than one time in ten days by work superintendent or
47
foreman. The results of the examination have to be put into the journal of
acceptance and visual examination of scaffolding (POT R M-012-2000, §
2.2.41).
8.3
Demands applied to scaffolding
All the following requirements for scaffolding are applied by three main
regulation documents already mentioned above. The main is the Technical
Regulation «On safety of buildings and structures», which has a reference to
SNiP 12-03-2001 «Work safety in construction. Part 1. General requirements.
Chapter 7.4.1-7.4.40». The other two documents are POT R M-012-2000
«Intersectoral Work at Height Safety Rules» and RD 34.03.204 «Safety Rules
for Works with Tools and Devices».
In this chapter the main safety demands applied to scaffolding are described.
Concerning that these three documents contain quite similar information it was
checked that they do not contradict each other or differ in any details.
It is necessary to say that there are different job titles mentioned in Russian
regulation documents. To make a direct translation of them into English is
almost impossible, because the whole system is different. That is why a special
glossary was made to explain the hierarchy on building site and different
responsibility levels. It can be found in Appendix 5.
Visual inspections of scaffolding have to be done regularly according to the
manufacturer’s manuals and also each time after a recess in usage, exposure
to extreme weather or seismic conditions or other consequences that could
affect structural strength and stability. If the works on the scaffolding were
suspended, then right before the resumption of works the scaffolding is subject
to acceptance once again. New handover certificate has to be made. If some
failures or damages are found then they have to be fixed and after that another
acceptance procedure is conducted.
48
The mass of one element to lift at once by one worker when using manual
assembly of scaffolding must be no more than 25 kg if the assembly happens at
height or no more than 50 kg if the assembly happens on the ground with
following lifting and installation by the crane power.
Wooden decks and wooden guard-rails have to be treated by impregnating fire
retardants. Nails in wooden elements are fully driven in or bended so that they
can cause no harm.
Ground surface on which the scaffolding is installed has to be even. Otherwise,
scaffolding must be equipped with adjustable base jacks to provide the
horizontality of construction.
Scaffolds must not be attached to balconies or other hanging parts of the
facade.
Loads must not be more than those mentioned in the scaffolding’s manual or in
the project. If more loads are needed to be applied then it has to be proved by
calculation of strength and, if necessary, the scaffolding structure must be
reinforced.
In the places of entrance to scaffolding there should be posters, which show the
allowed layout of load placement and maximum values of loads. Also there
should be emergency plans.
Metal scaffolds are produced from straight metal tubes, which have no dents,
cracks or other defects that affect the strength of elements.
Only metal fasteners (couplers, bolts) can be used for scaffolding.
Tubes must not be cracked, have splits, be covered with corrosion or visually
bended. Tube ends must be strictly perpendicular to their axes.
49
Steel scaffolding tubes and alloy ones cannot be mixed together in the same
scaffolding structure.
Loads applied to decking must not exceed values permitted in the passport of
scaffolding or in the project. Crowding in one spot of scaffolding is not allowed.
Decking must have flat and even surface. Gaps between the decks have to be
less than 5 mm.
The scaffolding width to perform the brickwork must be no less than 2 m. For
plastering works – 1,5 m. For painting works – 1,0 m. And there is an additional
demand for decks used when doing plastering and painting. If there are other
activities on the scaffolding under the level of plastering or painting or there is a
walkway underneath, then the gaps between the decks are not allowed.
When putting the decking elements onto the bearing tubes, it should be
checked that they cannot be easily displaced or shifted.
Under each pair of base plates in transversal direction should be put a wooden
plank of one piece with thickness over 5 mm. It is put on the compacted and
even ground surface. To make the plank lay even by using the fragments of
broken planks or other scrap is not allowed.
When constructing the scaffolding of more than 6 m in height there should be
more than two levels of decking: working (top) and guard (bottom) and each
working place on the scaffolding adjoined to the building facade should be
protected from above by one more decking.
To perform the works on several levels simultaneously along the same vertical
line without intermediate guard decking between the levels is not allowed.
The distance between the staircases, used for convenient access to the
scaffolding, must be less than 40 m. If the whole scaffolding structure is less
50
than 40 m in length then it must be equipped with two staircases at the least.
The pitch of staircase must not exceed 60º to the horizontal surface.
If the scaffolding is installed close to the driveways then the gap between the
scaffolding and the vehicles should be more than 0,6 m.
The height of the scaffolding is measured from the ground level, floor or
platform on which it is installed.
Decks and staircases have to be cleaned periodically during the works and after
their completion. In the winter time the snow and ice is needed to be removed
and the sanding to be done.
It is not allowed to work from the random props such as boxes or barrels when
being on the scaffolding.
Both assembling and disassembling of the scaffolding must be conducted in the
exact sequence like it is indicated in the manufacturer’s manuals. Workers
involved into the process must be instructed about the methods and sequence
of assembling and disassembling and about the safety measures. It is forbidden
for persons not involved in the process to access the place of assembling and
disassembling of scaffolding during the process.
It is not allowed to install metal scaffolding closer than 5 m to the wires of district
electricity lines. Otherwise, during the processes of assembling and
disassembling of scaffolding, the electricity power has to be cut off and the
wires earthed. Or the wires themselves have to be sheathed or dismantled.
During works at height the walkways beneath the scaffolding must be closed
and the hazardous area bordered and marked with safety signs. If the
scaffolding intersects the entrances to the building, then they must be equipped
with solid safety canopy to protect people from falling objects. Safety canopy is
tilted in the direction of scaffolding at the 20º angle.
51
If the constant human traffic is needed to be organized close to the scaffolding
then the walkway must be equipped with continuous safety canopy and facade
of the scaffolding is covered with protective mesh. The size of the mesh cell has
to be no more than 5x5 mm.
The gap between the wall of the building or industrial equipment and the
decking of the scaffolding cannot exceed 50 mm when doing brickwork and 150
mm during the other works.
When performing the insulation works the gap between the surface that is being
isolated and the decking must not be more than double thickness of the
insulation plus 50 mm. Gaps more than 50 mm must be covered in every case
when the works are not conducted.
It is not allowed to disassemble the scaffolding partially and leaving them for
conducting works without taking care of additional safety measures.
When using factory-made scaffolding it is necessary to do everything according
to manufacturer’s manuals. In addition to that, elements of different types of
scaffolding cannot be combined. Factory-made scaffolds must be equipped with
fastening elements that provide stiffness to the whole scaffolding structure.
Scaffolding systems be only be used the way they were originally intended.
Organization performs technical supervision to ensure that.
During the lifting of heavy loads onto the scaffolding or moving them along the
decking, it is necessary to avoid harsh hits against structural elements of
scaffolding.
Loads should be distributed as evenly as possible.
During the lifting of loads onto the scaffolding it is necessary to use an
additional rigging rope to prevent harsh hits against structural elements of
scaffolding.
52
Scaffolding must not be used as the storage for materials. There must be only
those materials that are currently used.
Works on the outside scaffolds have to be stopped in case of stormy weather
with a speed of wind of more than 15 m/s, heavy snowfall, fog, icing of ground
surface or other conditions hazardous to health of workers.
During the disassembling of scaffolding constructed alongside the building, all
the doorways of the first floor and balcony exits of every floor are closed within
the area of disassembling.
Scaffolding structures that have their decking at height more than 1,3 m above
the floor or the ground must be equipped with guard-rails. Height of guardrailing must be no less than 1,1 m. Vertical distance between the horizontal
elements of guard-railing – no more than 0,5 m. Height of toe-board – no less
than 0,15 m.
There are also special requirements when using mobile scaffolding. Slope of a
surface on which the mobile scaffolding is being moved in transversal and
longitudinal directions must not exceed the values, mentioned in manufacturer’s
manual for specific scaffolding structure.
Moving of mobile scaffolding is not allowed if the wind speed is more than 10
metres per second. Before moving the scaffolding it must be free of materials
and material containers. No people allowed on moving scaffolding.
Each caster or wheel of mobile scaffolding must have a locking device.
Access gates in the guard-railing of mobile scaffolding must open inwards and
have a locking device that protects them from spontaneous opening.
There is a poster in Appendix 1 that visually describes the most principal
requirements for scaffolding in Russia among above-mentioned in this chapter.
53
9 COMPARISON OF RUSSIAN AND FINNISH SAFETY
REQUIREMENTS FOR SCAFFOLDING
The Finnish and the Russian legislation both state that initially after the
assemblage of scaffolding it must be inspected and accepted for use. Special
attention here is paid to the load-bearing and guarding elements. If the
scaffolding was not used for quite a long period of time or after the heavy rains,
winds and other extreme weather conditions the whole structure has to be
checked very carefully once again.
Later on, during the works it has to be inspected at least once in 10 days in
building organizations according to Russian law. In Finnish law it is told that
during construction works the scaffolding must be checked at least once a
week.
In Finnish law it is said so that the results of inspection have to be recorded
somehow. In Russian regulations there is a standardized form of a journal that
should be filled by a superintendent (Appendix 2) and it is told also that after the
initial inspection the handover certificate has to be made.
There is nothing special mentioned in Russian regulations about how to restrict
the access to the scaffolding that is not finished or has not passed the
inspection because of failures or damages. The note is put by superintendent
into the journal and normally the scaffolding is restricted by the safety tape so
that everybody is informed about the prohibition of access (Figure 46).
Figure 46 Safety tape
54
Safety tape that indicates danger is usually red or red and white striped one.
In Finland there is also no strict rule about how to close the scaffolding from
access if it is not finished or needs to be repaired. It is told that there has to be
just some kind of indicator showing that it is not allowed to enter the scaffolding.
One way which is becoming more and more popular in Finland is scaffolding
tagging system «TELINEKORTTI» (Scaffolding card). It consists of safety tag
inserts and plastic holders which are showed on the Figure 1.1. The insert is
green coloured and being inside the holder it covers up the red-coloured
restrictive marking. On the insert itself there are the text fields provided to be
filled with the information about the last check. So if the insert was put into the
holder the green background is easily noticeable and the access is allowed. The
acceptable level of load is also mentioned there. But if there is no insert inside
the holder then the red restrictive signs are clearly visible. Also the insert itself
can be double-sided. If it is turned green the access is allowed, and if it is red –
not. And instead of being red from one side it can be yellow, showing that the
scaffolding is not finished yet. But the principle is quite the same in each case.
Initially this system of tagging was invented in United Kingdom by Scafftag Ltd
and nowadays is constantly gaining popularity all over the world. Their classic
scaffolding tag is shown on Figure 47.
Figure 47 Scaffolding tagging system
55
The scaffolding tag commonly used in Finland is shown on Figure 48 below. It is
green-sided meaning that the access to scaffolding is not restricted and
containing all information about the last inspection.
Scaffolding and work numbers
Location
Customer
Constructor
Length, Width, Height
Loads allowed: light, medium, heavy
Inspection:
Base
Anchors
Decking
Handrails
Stairs
Diagonal braces
Other elements
Date
Scaffolding builder
Work supervisor
Maintenance inspector
Figure 48 A closer look at the Finnish scaffolding tag
It is a good thing to use such kind of a scaffolding card – the same one
everywhere. Standardised way of informing is always useful, being well-known
for everyone who enters the construction site.
In Finnish law the gap between the wall and the decking of the scaffolding have
to be less than 250 mm. Otherwise the additional protective railing/falling
protection from the side which is close to the wall has to be installed. According
56
to Russian law the gap must be even less wide – the maximum width is 50 mm
when doing brickwork and 150 mm for other works.
By Russian legislation scaffolding structures that have their work level at height
more than 1,3 m above the floor or the ground must be equipped with guardrails. In Finnish law the maximum acceptable height without the guard-rails is
bigger being 2,0 m above the ground.
Minimum height of the guard-railing is 1,0 m in Finland and in Russia it is 1,1 m.
Maximum vertical distance between the horizontal elements of guard-rails is 0,5
in both of the laws.
By Finnish regulations the guard-rails have to sustain the point load of 1,0 kN
elastically (without plastic deformation). In Russian norms it is a little bit less
being 0,7 kN.
Both laws require the information about load-bearing capacity of scaffolding to
be put at places, where it can be easily visible. Russian legislation states that
such posters should be put near the entrances to scaffolding. In Finland this
information is usually provided by the above mentioned scaffolding tags.
The demands for mobile scaffolding are quite similar in both countries. Wheels
and casters must be equipped with lockers that restrain the scaffold from
moving during the works. It is not allowed to move the mobile scaffolding with
people on it.
Both laws are highly concerned on safety of scaffolding works. Some figures
are different, but generally they are quite similar. It is told everywhere in Finnish
law, that the scaffolding must be safe. For example, even it is mentioned that
the height without guard-railing can be up to two metres, it should be wisely
observed and if there is a high risk of stumbling and falling down, then it is
better to care about this.
57
10 WORK SAFETY IN PRACTICE
It is a common practice in every construction company being it Finnish or
Russian to check the work site safety all the time. In ARME OY this procedure
is called “Safety Walk”. Usually participants from the company (superintendents
and safety managers or safety director) are presented as well as participants on
behalf of the customer. During the safety walk a lot of things are inspected and
notes are taken. For example: condition of walkways, organisation and
cleanliness, materials storage, waste management, protection equipment, lifting
devices, scaffolding inspections (scaffolding tags and the overall condition of
scaffold structures) and so on. Finally the report, containing the list of faults and
things that require attention is formed, the person in charge of fixing them is
assigned and the due date is specified. Things that have to be fixed are
described more detailed below the list. Common work site safety walk-around
report used in ARME OY is presented in Appendix 4.
During the safety walk-around everything that needs fixing and taking care of
was found and put into this report.
Figure 49 shows the lack of starter elements of scaffolding. Installation of them
is required by the manufacturer’s manuals.
Figure 49 Starter elements missing
58
Not only the situation with scaffolding is checked during the safety walk but the
whole condition of work site. Figure 50 shows the place that needs some tidying
up. Unused decks and elements should be stacked, not just left here and there.
Figure 50 Additional cleaning required
On figure 51 there is an opening on the staircase, which is quite big and
hazardous, because easily lets someone to fall down into it.
Figure 51 Too large opening left on the staircase
The most serious problem found was the damage of scaffolding structure
illustrated on Figure 52. It has undergone quite serious deformations caused by
59
outer impact from some kind of machinery like forklifts or other vehicles which
operated with carelessness and hit the scaffolding.
Figure 52 Bending of ledgers and standards
The dismantling process needs to be performed with special care and all the
damaged parts of scaffolding, which suffered from bending, have to be
disposed and never used again.
It is a company rule that all the damaged elements have to be cut in two parts
right after dismantling so that nobody will able to use them in future.
60
11 SUMMARY
Main goal of the study was to compare scaffolding systems that are used
nowadays in Finland and in Russia. This included scaffolding material itself and
differences in legislation between these two countries.
Regarding the scaffolding material it is obvious that Russian-made scaffolding is
one step behind the German. First, the approach to presenting the products
varies quite much. It is not easy to get specific information from Russian
manufacturers, since they try to save their design from stealing. That caused
difficulties when gathering data for comparison. At the same time, German
manufacturers provide their products with open catalogues of characteristics
and technical information.
When comparing the systems themselves it becomes clear that Russian
manufacturers have not reached the European level yet, but this mostly comes
from the demand. Building companies are trying to get the cheapest offers
possible. The price is usually the main thing to consider. This is the main reason
for the fact that foreign systems are used on Russian building sites very seldom.
Anyway the constant development of Russian scaffolding is noticeable. Some
manufacturers are trying to improve their systems, bringing innovative ideas to
design of their joints or to production process.
The Russian legislation base is constantly changing. The attempts to simplify
the system and make it more up-to-date sometimes bring contradictions
between the existing documents. In this thesis work all the documents, which
deal with scaffolding were analysed and information from them was sorted out
to make all the requirements transparent and understandable. As a result,
similarities and differences between Russian and Finnish law were found.
During the work with thesis it was discovered that it is not easy to explain some
features of Russian construction field, for example, job titles on Russian building
61
sites. There are quite many of them, unlike in Europe. And it was significant to
explain each work title, its level of responsibility and job description, because
they are mentioned quite often in legislation documents.
It was planned so that in the end of this study it would be possible to say if there
are opportunities for European scaffolding companies to do business on
Russian market with foreign scaffolding systems. The answer is definitely
“YES”. Although, the prices are much higher, the advantages of higher-quality
products are slowly becoming to be realized. It is now already possible to meet
German scaffolding on major construction sites in Russia, even though it is not
a common practice yet.
Such expansion of higher-quality systems will definitely push Russian
manufacturers to improve their products. And from the work safety point of view
it is the step forward, because scaffolding itself ever stays to be a business of a
very high risk.
62
FIGURES
Figure 1 Modular scaffolding - renovation of the Landwasser Viaduct in
Switzerland
Figure 2 Scheme of scaffolding materials and their treatment
Figure 3 Scratch consequences on zinc-coated and painted metal pieces
Figure 4 Bamboo high-rise scaffolding in Hong Kong, China
Figure 5 Scaffolding failure in San Francisco caused by stormy winds
Figure 6 Main elements of scaffolding
Figure 7 Scaffolding dimensioning terms
Figure 8 Guardrails and toe-boards
Figure 9 Cup-Lock joint principle
Figure 10 Wedge driving stages of Ring-Lock modular scaffolding system
Figure 11 Ring-Lock joint principle
Figure 12 Angle adjustment scheme
Figure 13 Ledgers, transoms and diagonals in different lengths
Figure 14 Starter element
Figure 15 Tubes connected with Right Angle Rigid Couplers
Figure 16 Tubes connected with Swivel Couplers
Figure 17 «Tube-and-Coupler» scaffolding
Figure 18 Principal scheme of tubular welded frame scaffolding
Figure 19 Modern way of fastening the braces
Figure 20 Locking pin work principle
Figure 21 Fabricated frame mobile scaffolding
Figure 22 Modular mobile scaffold gantry in the tunnel, Australia
Figure 23 Plastic deformation of the ending of vertical standard by RINSTROY
Figure 24 Ring-Lock by RINSTROY, secured on tube by plastic deformation
Figure 25 Common spigot fitting with an additional inner tube
Figure 26 Common spigot fitting with additional screwed inner tube and welded
Ring-Lock
Figure 27 Vertical standards with welded Ring-Locks by MDN-Prom
Figure 28 Spigot connection of standard
Figure 29 Development of Ring-Lock joint by MDN-Prom
63
Figure 30 Wooden decks laying upon the longitudinal ledgers
Figure 31 Strengthened horizontal element and long metal deck
Figure 32 Ring-Lock joint by MSK
Figure 33 Patented joint by SIMAN+
Figure 34 Bearing ring / Cup
Figure 35 Grip
Figure 36 Cone with a locking pin
Figure 37 «Star» joint by SIMAN+
Figure 38 Connection of elements to the «Star» joint
Figure 39 Scaffolding by Rinstroy. Wooden decking.
Figure 40 Metal scaffolding deck
Figure 41 Wedge head by MDN-Prom (left) and fully casted wedge heads by
RINSTROY, SIMAN+ and MSK (right)
Figure 42 Different types of ledgers and transoms by Alfix
Figure 43 Deck carried by U-shaped transom
Figure 44 Ring-Locks from left to right: Alfix, RINSTROY, MDN-Prom, SIMAN+
Figure 45 Wedge heads by Alfix (left) and SIMAN+ (right)
Figure 46 Safety tape
Figure 47 Scaffolding tagging system
Figure 48 A closer look at the Finnish scaffolding tag
Figure 49 Starter elements missing
Figure 50 Additional cleaning required
Figure 51 Too large opening left on the staircase
Figure 52 Bending of ledgers and standards
64
TABLES
Table 1 Main characteristics of the scaffolding system by RINSTROY
Table 2 Main characteristics of the scaffolding system by MDN-Prom
Table 3 Main characteristics of the scaffolding system by MSK
Table 4 Main characteristics of the scaffolding system by SIMAN+
Table 5 Load-bearing capacities of Russian scaffolding systems
Table 6 Widths of scaffolding available from Russian manufacturers
65
REFERENCES
Alfix Scaffolding System Modul PLUS II Catalogue.
http://www.alfix.de/downloader/ModulPlusIIEnglisch.pdf
(Accessed on 26 April 2011)
Federal Law №184 from 27th of December 2002. About Technical Regulations.
Federal Law №384 from 30th of December 2009. Technical Regulation
«On safety of buildings and structures».
Find Scaffolding website, 2011. Bamboo Scaffolding.
http://www.findscaffolding.com/bamboo_scaffolding.php
(Accessed on 26 April 2011)
GOST 24258-88, 1988. «Different types of scaffolding. General specifications».
GOST 27321-87, 1987. «Demountable tubular scaffold for constructional work.
Specifications».
Health and Safety Authority of Ireland, 2008. Code of Practice for Access and
Working Scaffolds.
Layher GmbH & Co. KG. Australian website. Mobile Scaffold Gantry in Tunnel.
http://www.layher.com.au/scaffold/mobile-scaffold-gantry-tunnel.html
(Accessed on 11 April 2011)
Levy, Sidney M. 2000. Construction building envelope and interior finishes
databook. Section 3. Structural Steel, Joists and Metal Decking. USA: McGrawHill.
N.C. Department of Labor. Occupational Safety and Health Division, 2008.
A Guide To Safe Scaffolding. USA, North Carolina, Raleigh.
POT R M-012-2000, 2001. Intersectoral Work at Height Safety Rules.
RD 34.03.204, 1996. Safety Rules for Works with Tools and Devices.
SNiP 12-03-2001, 2001. Work safety in construction. Part 1. General
requirements, paragraphs 7.4.1-7.4.40.
Sosiaali- ja terveysministeriön päätös (156/98), 1998. Työtelineiden ja
putoamisen estävien suojarakenteiden käytöstä rakennustyössä. Helsinki.
66
APPENDIX
1
1 (1)
RUSSIAN SCAFFOLDING ASSEMBLY AND USE POSTER
APPENDIX
2
1 (1)
SCAFFOLDING HANDOVER CERTIFICATE
APPENDIX
3
1 (1)
JOURNAL OF ACCEPTANCE AND VISUAL EXAMINATION
OF SCAFFOLDING
Recommended form of the journal:
Place of installation of
scaffolding, its height and
organization that
performed the assemblage
Type of scaffolding,
who has accepted the project
Date of acceptance or visual
examination of scaffolding and
handover certificate number
1
2
3
Conclusions concerning the
suitability of scaffolding for
use
Person who performed
acceptance or visual
examination of scaffolding,
job title, organization
Signature of a person who
performed acceptance or visual
examination of scaffolding
4
5
6
APPENDIX
4
1 (1)
WORK SITE SAFETY WALK AROUND REPORT
APPENDIX
5
1 (2)
JOB TITLES ON RUSSIAN BUILDING SITES
There are a lot of job titles on building sites in Russia. Their descriptions and
responsibilities vary greatly from one company to another. However, it is possible to
describe the most commonly used hierarchy.
Site manager (Superintendent) – "Nachal'nik ychastka"
Site manager is the person in charge of everything on the whole construction site or
the part of it. He is a key player in the performance of the schedule and the coordination of all activities on the site. He is the head of all the superintendents.
Superintendent (Assistant superintendent or Area superintendent) – "Prorab"
The term "Prorab" comes from the combination of two words: PROizvoditel' RABot
(Manager of works).
Superintendent is the principle manager of works. On large projects different
superintendents may be used to control different segments of work. All the labour,
including engineering workers are subordinate to superintendent. Superintendent
gives instructions to workers through foremen.
Foreman – "Master"
Foreman is the head of all the labour and the direct manager of works in a particular
work area of the construction site. He is subordinate to superintendent. Foreman is
responsible for the quality of work produced by workers. He does not perform the
actual work with tools.
These were completely managerial positions.
Brigade leader – "Brigadir"
Brigade leader is the head of a brigade or workers. He is actually performing the
work with tools and at the same time spending some time to control its crew.
Brigade leader is assigned by the general director of the organization (according to
nomination by superintendent) from the most qualified workers, who possess
APPENDIX
5
2 (2)
organizational skills. In huge brigades, brigade leader can be free from performing
the work with tools.
Specialized brigade – "Spetsializirovannaja brigada" – up to 25-30 workers.
Consists of several work teams, which perform the same work task (concreting,
plastering, brickwork)
Complex brigade – "Kompleksnaja brigada" – up to 50 workers.
Consists of several work teams, which perform different work tasks that go
simultaneously. For example, complex brigade of concrete workers: formwork
assemblers, reinforcement workers, concrete pourers.
Work team leader – "Zven’jevoj"
Work team leader is the head of a work team. He is assigned by the general director
of the organization (according to nomination by Brigade leader or Foreman) from the
most skilled workers.
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