- OTT Hydromet

Discharge measurement
OTT cable way systems
Fixed systems with electrical or mechanical
double-drum winch
OTT Cable Way Systems
Safety in discharge measurement
For vertical method based discharge measurements, cable way systems are essential.
Mobile measurements in water may be too dangerous and measurements cannot always
be performed from bridges or survey vessels. Therefore, cable way systems have been
used in numerous rivers and canals and proven to provide dependable service for many
years. Their functional and rugged design ensures installation flexibility, smooth operation,
and safe working.
The new OTT cable way systems rely on well-tried technology. They are DEKRA type
approved and meet all applicable safety requirements. In addition to the cables, the basic
components include one or two pulley blocks, the tensioners, and the moving trolley. It
carries the instruments, e.g. a floating current meter or a mobile river discharge measurement
system across the water cross section.
The towing cable and current meter cable are driven by an electrical or optionally by a
mechanical double-drum winch. An electronic distance and depth meter assists in correctly
positioning the instrument. When the system is electrically driven, the winches are easily
and safely controlled from a control unit that is fitted with a joystick, large display, and
internal measuring feature. Of course, an external meter such as the OTT Z400 unit may be
connected as well.
OTT cable way systems – major components
Overview: components of an OTT cable way system
Track Cable
Cable Tensioner
Towing Cable
Limit stop
Trigger cam
Pulley Block
support post
support post
Current Meter Cable
or electrical
Gas-spring tensioning device
Middle piece
Suspended current meter
Schematic of an OTT cable way system.
Pulley block
The sturdy cast aluminium pulley block is corrosion-resistant.
Because of its slim design it requires only little space. In addition to
guide pulleys for the various cables, the pulley block includes the
attachment feature for the track cable (winch side).
Track cable
The track cable is a galvanised compacted and steel-reinforced
special cable that acts as a "rail" for the trolley. It features a high
breaking strength and is optimised with regard to track cable
tension (pre-stretched). This helps minimise residual elongation so
that re-tensioning will be required as an exception only. The round
smooth surface minimises wear of the pulley and ensures silent
Towing cable
The corrosion-protected towing cable is made of galvanised wires
and used to move the trolley along the track cable to the desired
vertical position. The strong towing cable is designed to be used for
at least 10 years.
The trolley features a single-arm design and has, in addition to the
guide pulleys, only one single idler pulley. Thus, it will run silently
and smoothly even after years of operation. When replacing the
track or towing cable, the trolley may easily be removed and
re-installed without the risk of bruising.
Current meter cable
The current meter cable (measurement cable) is a special cable that
is made of galvanised steel wires and designed for long-term use.
At its lose end, the centrepiece of the floating current meter/
instrument is engaged to the cable. During measuring operation, an
insulated conductor within the current meter cable transmits the
electrical signals (current meter pulses, ground sensor).
Cable tensioner
Both track and towing cable have a cable tensioner. Cable way
systems of up to 20 m span length have a turnbuckle tensioner. For
larger span lengths, a gas pressure spring tensioner is used. It
compensates for temperature effects by automatically increasing or
decreasing the cable tension. This avoids slack caused by high
temperatures or increased load to the support posts caused by
cold temperatures. The gas pressure spring tensioner does not use
oil. So there is no risk of water contamination by oil.
State-of-the-art drive, perfect service
Compact and functional – the double-drum winch
The compact double-drum winch is the primary item used to move
the trolley in horizontal direction as well as to lower or raise the
floating current meter. It has a multi-groove drive pulley for the
towing cable and a cable drum for the current meter cable.
Optionally, it may be driven electrically or mechanically. The gearbox
is lifetime lubricated; thus, no lubricating or oil changes are required.
The smoothly operating brake/clutch combination facilitates
changes between lowering/raising operations and horizontal travel.
An electronic meter for both depth and distance indicates the
current position of the instrument so that it may exactly be placed at
the desired measuring location. Safety as well as protection against
damage are provided by the overload clutch: In case of overload,
e.g. when the instrument gets caught by flotsam, the current meter
cable will be wound off automatically.
The double-drum winch was designed according to the LAWA recommendations for the safety of cable way systems and is type-tested. Depending on the requirements of the station, the winch may be
supplied with horizontal or vertical cable exit. And because no
gauge station is like another one, the winch is available with righthand or left-hand side operation.
Convenient and safe – the controller
—— Portable wired unit that is used to intuitively control the
electrical double-drum winch by means of a joystick;
—— Large display – easily read indicators for velocity, position of
trolley/current meter height, measuring activity, and measured
—— Advanced and future-proof control concept based on the
Siemens Simatic S7 PLC;
—— Emergency Stop switch to ensure safe working in critical
—— Fully automated low-noise shifting operation of the clutch;
—— Single-handed operation, even when wearing protective gloves;
—— Potentiometer for infinite speed setting;
—— Internal measuring features for time/pulse and integrated
—— An external signal counter set may be used such as the OTT
Z400 unit that is easily parameterised via menu feature;
—— Optical and audio alerts in case of ground contact;
—— Easy switching to electronic control of a sample collector;
—— Diagnostic features and alarm information.
Mechanical double-drum winch
—— The towing cable is driven by means of a hand crank –
ergonomically designed and easily operated safety crank
including a load-actuated brake for safely holding the load;
—— Shift lever for easily switching between travelling and raising/
—— Electronic meter – indicates both horizontal and vertical
positions of the instrument;
—— Electrical drive may be retrofitted.
Electrical double-drum winch
—— Maintenance-free direct drive for the towing cable;
—— Three-phase motor with state-of-the-art inverter technology
for optimum start-up and speed performance;
—— Travel speed (rotary speed) may be adjusted in 3 steps or
infinitely up to 0.5 m/s;
—— May be switched to manual operation with safety crank
– operational also without electrical power.
—— Optional: Uninterruptible power supply (UPS) – for reliably
completing an active measurement in case of power failure;
—— Towing cable fitted with trigger cams – for automatically
disabling the drive when an end position has been reached;
—— When the ground has been reached, the lowering movement
will automatically be disabled.
Service from the beginning
Typically, OTT cable way systems are installed by our OTT Hydro­
Service department. Our specialists are well-trained for this job, use
the appropriate equipment and have many years of experience. This
ensures careful and above all safe installation.
All components of the OTT cable way system do not require any
maintenance. Neither lubrication nor oil changes are required. In
case of cable way systems for hydrological service, regular
inspections by authorised experts are useful. Many countries have
exact regulations for this. OTT HydroService performs also these
inspections in a reliable manner and does any service, replacement,
or adjustment operations efficiently and professionally.
OTT cable way systems – sophisticated to detail
Depending on the different requirements of the stations, OTT cable way systems are available in five designs with optional mechanical or
electrical double-drum winch. For the cable tensioner, a turnbuckle tensioner is used for smaller waters, while a gas pressure spring tensioner is used for larger waters. This ensures proper tension of both track and towing cables even when temperatures are varying. All OTT
cable way systems are type-tested according to the LAWA recommendations "Safety of Cable Way Systems" and to the European
Machinery Directive 2006/42/EC.
Winch exit
meter cable
Cable tensioner
Installation of
cable tensioner
Winch support post
20 m
Winch support post
20 m
Gas pressure spring
Winch support post
160 m
Gas pressure spring
Opposite support post
160 m
Gas pressure spring
Opposite support post
160 m
We will be pleased to help you to find the optimum system for your station. Also in case you
have other questions, e.g. regarding required cable lengths, we will be on hand with help
and advice for you.
Technical data
Mechanical Double-drum Winch
Span Length
-- Including turnbuckle tensioner:
up to 20 m
-- Including gas pressure spring tensioner:
up to 160 m
Distance/depth meter
-- Design: 5-digit LCD;
incl. Reset keys
-- Resolution: 1 cm
-- Back-up battery: 9 V battery
(alkaline type)
Cable diameter
-- Track Cable: 16 mm
-- Towing Cable: 6 mm
-- Current Meter Cable: 3.5 mm
Dimensions (W x H x D)
-- incl. hand crank: approx.
570 x 770 x 670 mm
-- without hand crank: approx.
450 x 750 x 560 mm
Double-drum Winch
Right-hand side or left-hand side
approx. 100 kg
Cable exit
Horizontal or vertical
without current meter cable and hand crank
Current meter cable drum
-- Rated tension force: 1250 N
-- Maximum tension force: 3000 N ±20 %
-- Tripping force of safety friction clutch:
3000 N ±20 %
-- Maximum useable cable length: 164 m
-- Maximum number of cable layers: 6
-- Minimum number of windings remaining:
3 (≙ 3.1 m)
orque required on crank
11 N/m (for 100 kg of weight)
Crank length
0.3 m
Operating temperature
-20 °C +60 °C
Storage temperature
-40 °C ... +85 °C
Air humidity
0 % ... 95 % RH (non-condensing)
Electrical Double-drum Winch
Electrical drive
-- Supply voltage: 230 V / 50 Hz
-- Control voltage: 24 V DC
-- Motor power: 1.5 kW
-- Degree of protection: IP 54
-- Sound pressure level: 70 dB (A)
OTT Hydromet GmbH
Ludwigstrasse 16 · 87437 Kempten
Phone +49 831 5617-0 · Fax -209
info@ott.com · www.ott.com
Dimensions (W x H x D)
-- Electrical double-drum winch:
approx. 570 x 900 x 670 mm
without hand-crank for emergency operation
-- Control cabinet: 600 x 600 x 250 mm
-- approx. 135 kg (incl. motor)
without current meter cable and hand crank
-- Motor: 35 kg
-- Control cabinet: approx. 30 kg
Operating unit including chest strap
-- Dimensions (W x H x D):
280 x 200 x 130 mm
without joystick and chest strap
-- D
isplay: 5 rows, monochrome,
incl. function key assignments
-- Operating controls: Joystick, Emergency
Stop pushbutton, 10 function keys
(may also be used as numerical keys),
cursor keys, permanent function keys,
additional potential meter for speed setting
-- Acoustic alert: internal buzzer sounds in
case of ground contact
Operating temperature
-- Standard: 0 °C ... +50 °C
-- With opt. heater: -20 °C ... +50 °C
-- With opt. cooler: 0 °C ... +60 °C
Storage temperature
-40 °C ... +85 °C
Air humidity
0 % ... 95 % RH (non-condensing)
© We reserve the right to make technical changes and improvements without notice.
18.001.500.P.E Version: 01-08/2016
Cable Way System
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