Considerations of electric powered horizontal

Considerations of electric powered horizontal
XXX
XXXXX
1
Considerations
of electric
powered
horizontal
transportation
at container
terminals
ELECTRIC POWERED HORIZONTAL
TRANSPORTATION
Contents
1. INTRODUCTION���������������������������������������������������������������������������������������������������������� 4
2. HORIZONTAL TRANSPORTATION ������������������������������������������������������������������������ 7
3. HYBRIDS ���������������������������������������������������������������������������������������������������������������������� 9
4. WHY FULLY ELECTRIC?���������������������������������������������������������������������������������������� 10
5. THE FULLY ELECTRIC AGV ���������������������������������������������������������������������������������� 10
6. NEW TECHNOLOGY BATTERY ���������������������������������������������������������������������������� 11
7. THE ELECTRIC POWERED KALMAR FASTCHARGETM SHUTTLE AND .
STRADDLE CARRIER���������������������������������������������������������������������������������������������� 12
8. FAST CHARGING������������������������������������������������������������������������������������������������������ 14
9. ELECTRIC AGV AND FASTCHARGE AUTOSHUTTLE CONCEPT .
COMPARISONS�������������������������������������������������������������������������������������������������������� 17
10. CONCLUSION ���������������������������������������������������������������������������������������������������������� 18
2
Summary
Along with the use of hybrid power sources, interest in full electric
powered horizontal transportation at port terminals has never been
higher. Whether driven by environmental legislation, local pressure
groups or pure economics, the need to reduce emissions, noise or
over-complicated maintenance is growing. When implementing a quay
to stacking area transportation system, there are basically three electric
powered alternatives. Which concept provides greater added value
completely depends on the characteristics and requirements of the
application.
At automated container terminals utilising automated stacking cranes
(ASC), the two options are the flatbed automated guided vehicle
(AGV) or the shuttle carrier, which can be manually operated or fully
automated. As container movement between the quay and the
container yard is a potential “bottleneck” in the terminal, the Kalmar
FastChargeTM shuttle carrier already offers a major advantage by fully
decoupling activities at both ends. Various derivatives of the AGV offer
decoupling at the ASC but coupled operations at the ship-to-shore
crane (STS) can still limit productivity.
In a straddle carrier terminal, waterside and landside operations are
already fully decoupled with a single machine handling both horizontal
transportation and stacking. The speed, reach and flexibility of the
Kalmar FastCharge straddle carrier allow terminals to use a single type
of equipment for all container operations, either manually operated or
fully automated.
The majority of all-electric AGVs presently in use utilise lead-acid
batteries which, due to the long charging times, require automated
battery replacement and charging stations. Newer technology lithiumion power sources, as used in the Kalmar FastCharge shuttle and
straddle carriers, now charge so quickly that the battery stays in the
vehicle and replacement is unnecessary.
There is no ‘one-size-fits-all’ solution, which creates the need to be
aware of the actual performance, characteristics and parameters of
each alternative, to ensure an objective evaluation is achieved. This
white paper attempts to provide an objective comparison between the
systems in order to help determine which concept is a better fit for a
particular terminal.
ELECTRIC POWERED HORIZONTAL
TRANSPORTATION
The Kalmar AutoStrad™ is
the ideal solution for mediumsized and large terminals
where high equipment
flexibility and minimal labor
costs are key requirements.
The berthing
time at the
terminal quay
needs to be
as short as
possible.
4
1. INTRODUCTION
In recent decades, container volumes handled worldwide have
continuously increased as a result of globalisation, economic growth
and geographical distribution of activities. Overseas container transport
costs have considerably decreased due to economies of scale by
continuously increasing vessel sizes from 4,000 TEU in the early 1990s
to 14,500 and above today. Larger container ships place an increasingly
heavy demand on terminal infrastructure to handle the increased
number of containers moving to and from the quayside.
Time is money and as the container ship only really makes money while
at sea, the berthing time at the terminal quay needs to be as short as
possible. This can only be achieved by fast loading and unloading,
which requires close cooperation between the quayside ship-to-shore
cranes and the container stacking area. For many years, the straddle
carrier and terminal tractors with one or multiple chassis were the
default options for horizontal transportation with straddle carriers
capable of handling both horizontal transportation and stacking.
Automated straddle carrier
Straddle carriers are
capable of handling both
horizontal transportation
and stacking.
ELECTRIC POWERED HORIZONTAL
TRANSPORTATION
Kalmar ASC System
Kalmar’s end-to-end ASC System
encompasses Kalmar ASC, automated
truck handling, (Auto)Shuttles™ and
related software solutions.
6
2. HORIZONTAL TRANSPORTATION
In the early 1990s, the flatbed AGV was the first driverless horizontal
transportation system to be introduced into terminals. While many
improvements have been made since, the flatbed AGV is basically an
automated version of the chassis used for horizontal transportation at
that time. Today, the high productivity of STS cranes can be limited by
the AGV’s need to be present to load and unload containers, and the
coupling of the work cycles of the quay and yard cranes.
Even with developments like the active lift AGV, operations are still only
partially decoupled at the stacking area. As a rough guide, the coupled
operation at the STS crane requires a minimum of five AGVs to be
deployed for each STS crane. A proposed cassette AGV also promises
decoupling at the quay with a portable cassette. However, with no
existing commercial installations, how cassette placement will be
achieved in the dynamic environment of the STS crane remains unclear.
The ideal decoupling buffer is created by placing the containers on the
ground at the STS crane, to be picked up and dropped on the ground
at the waterside interchange area. This is where the interest in the
shuttle carrier as a form of horizontal transportation originated. By fully
decoupling STS and ASC activities, one shuttle carrier can achieve the
same productivity as two AGVs. This decoupling adds buffer zones
both at the STS and ASC, making exception handling, whether caused
by delays in loading or unloading, easier to manage.
ELECTRIC POWERED HORIZONTAL
TRANSPORTATION
Today’s modern terminal utilising
automatic stacking cranes (ASC)
led to the further development
of horizontal transportation to
remove the potential bottleneck
at the quay.
8
The innovative shuttle carrier concept developed by Kalmar, a smaller
1 over 1 stacking version of the straddle carrier, was first tested at the
port of Helsinki in 2003. The Kalmar AutoShuttle™ is able to transport
single 20 and 40 foot containers, picked up from the ground, as well
as two 20’ boxes in twin-lift operation. With the ability to pick up any
container rather than only the outermost and to stack containers two
high, the AutoShuttle offers more versatility, especially in pooled allocation
schemes serving more than one STS crane and dual cycle operations
with simultaneous loading and unloading. Whether fully automated or
manually operated, the shuttle allows faster fully decoupled container
transfer in the terminal.
Diesel/electric
driveline is
generally more
reliable and
requires less
maintenance
than diesel.
3. HYBRIDS
Today, both AGVs and shuttle carriers offer electric driveline using a
diesel engine as the main power source. Diesel/electric driveline has the
same advantages as diesel but is generally more reliable and requires
less maintenance. The diesel/electric has also seen the introduction of
hybrid designs much in the same way as cars, allowing a considerably
smaller engine with batteries or super capacitors supplying peak load
capacity.
New battery technology allows the engine to be sized for average
power, whereas the use of the lower energy storage super capacitors
requires a larger engine sized for maximum peak demand. These
designs also feature regenerative energy systems to convert braking
and spreader lowering energy into electric power that is stored for later
use. An automated stop-start system chooses the optimal balance
between engine and battery power, which also extends the operational
life of engine and generator, as well as maintenance intervals.
Consuming up to 40% less fuel than existing shuttle carriers on the
market, Kalmar hybrid shuttle carriers with lithium batteries emit over 50
tons less CO2 per year than a traditional diesel unit.
ELECTRIC POWERED HORIZONTAL
TRANSPORTATION
As
environmental
legislation
becomes
more stringent,
electric driveline
with batteries
is the only
alternative.
4. WHY FULLY ELECTRIC?
While hybrid systems provide excellent economy and reduced
emissions, the ultimate target is an emission-free (at least at the point of
use) horizontal transport solution. As environmental legislation becomes
more stringent for CO2 and NOx, especially the latter, electric driveline
with batteries is the only alternative. As well as no emissions to the
atmosphere, other advantages include less noise, reduced maintenance
with a smaller number of vehicle components and up to 50% increased
energy efficiency compared to diesel/electric driveline.
5. THE FULLY ELECTRIC AGV
Since the first installation in 2013, the current commercial usage of
electric AGVs has been possibly limited by the increased investment
cost in the necessary batteries and charging facilities. Using lead-acid
battery technology, these AGVs require almost 10 tons of batteries to
provide a useful operational working time of eight hours. The actual
running time is considerably less. One study quotes a moving ratio of
40% and an operational stoppage or unpowered waiting time of 60%,
implying that for 36 minutes of each hour the AGV is non-productive.
Recharging requires removal and replacement of the battery, which
although fully automated requires the AGV to be driven to the exchange
station and remain inactive while the battery is replaced.
As recharging takes at least six hours, at least three battery packs
are required for two AGVs. For example, at an all-electric installation
in Rotterdam, a total of 87 battery packs were initially supplied for
37 electric lift AGVs with two robotic battery exchange stations.
Development of the all-electric AGV required a redesign of the vehicle
chassis to accommodate the weight of the batteries and distribute
the load uniformly to all four wheels. Newer designs based on fast
charge battery technology have been announced, but at the time of
writing, details of actual operation and charging methods have not been
disclosed.
10
6. NEW TECHNOLOGY BATTERY
Lithium-ion (Li-ion) battery technology, first proposed in the 1970s,
today powers everything from phones and personal computers to
electric cars and buses. Li-ion development has been rapid and, unlike
its 150 year old lead-acid counterpart, has seen a steady progression
in performance and capacity with recent developments providing the
advantage of extremely fast charging.
Opportunity charging in public transportation, such as large capacity
electric buses, uses the high-charging capability to partly recharge the
battery in as little as 15 seconds while passengers are alighting and
boarding at bus stops.
Compared to lead-acid, these batteries offer up to 80% weight savings
for the same capacity and have a much better low-temperature
performance with 80% of full capacity still available at minus 30°C. In
addition to the enhanced efficiency and energy-conserving qualities of
Li-ion batteries, this technology offers a high level of safety compared
to alternative options. Being entirely free of carbon they avoid thermal
runaway or overheating, which is a main cause of fires in traditional
energy storage systems.
The higher
cost of lithiumion batteries is
partially offset
due to the
fewer number
of vehicles
required.
The higher cost of lithium-ion batteries when using a fully decoupled
shuttle operation is partially offset due to the fewer number of vehicles
required compared to the partially decoupled operation with AGVs.
Whether using a battery changing station or fast charge technology,
twice as many AGVs are still required to achieve the same moves per
hour capability of the shuttle. One manufacturer has announced the use
of Li-ion batteries in a terminal trailer concept and promises a run time
of 12 hours. However, the battery then has to be charged for 2.5 hours
during which time the vehicle is non-productive.
7. THE ELECTRIC POWERED KALMAR FASTCHARGETM SHUTTLE AND
ELECTRIC POWERED HORIZONTAL
TRANSPORTATION
STRADDLE CARRIER
12
Freed from the lead-acid six to eight hour charge cycle, the lighter fast
charge batteries have allowed Kalmar to replace the diesel engines
in shuttle and straddle carriers without a weight penalty, offering
tremendous advantages in the practicality of an existing vehicle design.
Experience of the batteries already utilised in Kalmar’s hybrid straddle
carrier have enabled engineers to optimise battery capacity and
onboard charging is supplemented by regenerative systems to store
reclaimed braking and spreader lowering energy.
The Kalmar
FastCharge
shuttle and
straddle carrier
offer a truly
flexible concept
for existing
and greenfield
terminals.
Available in both manually operated and automated versions, the
Kalmar FastCharge shuttle and straddle carrier offer a truly flexible
concept for existing and greenfield terminals. In hybrid terminals, where
ASCs are being partially introduced, they offer the unique opportunity for
gradual expansion while retaining fully decoupled container transfers.
When modernising the terminal with automation increasingly taken
into use, existing manual shuttles and straddle carriers can be fully
automated leading to improved return on original investment and
optimised total cost of ownership.
Kalmar
FastChargeTM
Solution
Kalmar
FastCharge™
Solution
Charging type: DC fast charging
Charging power: 0-600 kW
Time to full charge: 5 min @ 600 kW
Typical charging time in operation:
30 to 180 sec @ 600 kW
Contact dome
Charging pole
WLAN communication between
machine and charging station
Charging power station
All essential charging
information available
for the driver in
manual operation
Pantograph
Automated machine position recognition
and charging sequence
ELECTRIC POWERED HORIZONTAL
TRANSPORTATION
Fast charging stations
can be installed along
the shuttle working route
in order to utilize idle
time for charging.
8. FAST CHARGING
Battery charging of the Kalmar FastCharge AutoShuttle is achieved with
an inverted pantograph direct current charging system, fully automated
in operation and similar to the system in use on electric buses. Location
of the current collector on top of the shuttle adds to the safety of the
solution and protects it from damage. This is possibly another reason
why Li-ion technology is not used in AGVs, as on-board charging would
usually be at ground level and very difficult to reliably automate.
Non-contact methods such as inductive charging have also been
investigated but are unable to deliver the power required without
considerable energy loss. The fast charge battery technology makes it
possible to utilise very high charging rates, which by being scalable up
to 600 kW allow rapid on-board charging. One pantograph located
14
In the straddle carrier
terminal there is high
flexibility in charging
station installation.
One pantograph
on the working
route can serve
several vehicles
as charging is
flexible.
on the FastCharge shuttle carrier route can serve several vehicles as
charging is very flexible. Since the driving cycles are short, frequent
thirty-second charging periods, depending on the shuttle cycle and
state of battery charge, do not slow down container transfers and
enable the vehicle to be utilised to its maximum effectiveness.
The impact of fast charging to the local power grid, in terms of
electricity quality, is minimised with an intelligent charging system
control. This more frequent charging avoids the deep discharge, which
can shorten the life of any battery. Pantograph charging stations can
also be more easily positioned than battery exchange stations, with
convenient locations on shuttle routes to eliminate disruption of the
shuttle work cycle.
ELECTRIC POWERED HORIZONTAL
TRANSPORTATION
Terminal A (Europe)
Note!
On some
terminals
shuttle carriers
are used in
land side
operations as
well.
16
Terminal B (Europe)
Terminal C (Americas)
Terminal D (Europe)
x
11
x
8
x
8
x
15
x
26
x
22
x
27
x
84
Ratio
2.4
Ratio
2.8
Ratio
3.4
Ratio
5.6
9. ELECTRIC AGV AND FASTCHARGE AUTOSHUTTLE CONCEPT
COMPARISONS
Terminal E (Europe)
Terminal F (Americas)
x
11
x
14
x
62
x
72
Ratio
5.6
Ratio
5.1
As previously described, in most terminals one FastCharge AutoShuttle is
capable of virtually the same productivity as two AGVs. The reduction in
vehicle numbers compensates for the higher initial cost of the FastCharge
solution with additional savings when the AGV charging stations are taken
into account.
The AGV is very dependent on the trouble-free operation of the robotic
charging station, which typically dictates a second station to provide a
degree of redundancy. Owing to the weight of batteries involved, the
battery change/charging station requires very substantial foundations,
which may also dictate a less than ideal location with increased travel
time for charging. The FastCharge charging station requires considerably
less space and several of them can be conveniently located on regularly
used routes. Compared to a lead-acid robotic battery exchange and
charging station for 30 AGVs, the cost of the FastCharge station for 15
equally productive shuttles is approximately 80% less when building costs
are included.
Practicality is another area in which the FastCharge AutoShuttle scores
highly by using a tried and trusted vehicle design. Unlike the AGV, where
the vehicle was designed around the battery, tried and proven features
of the diesel/electric and battery assisted hybrid shuttle carriers were
used in the development of the FastCharge model. As well as shortening
development time, this allowed Kalmar engineers to concentrate on the
new technology aspects and avoid redesign of the whole concept.
Battery lifetime is a serious consideration in the purchase of any electric
vehicle. Typically, battery manufacturers quote lifetime in cycles. For leadacid deep cycle batteries this equates to between 400 and 800 cycles,
depending on the degree of discharge. One AGV manufacturer promises
1,200 cycles, with the recommendation that the almost 10 tons of
battery per AGV is replaced every 2.5 years. By comparison, fast charge
battery manufacturers quote as many as 20,000 cycles, which, with
the increased frequency pantograph charging method, conservatively
equates to a more than 10-year battery lifetime in the FastCharge
solution.
Space, in terms of real estate, is an expensive resource in both new and
expanding terminals. The increased manoeuvrability of the AutoShuttle
allows for higher productivity and maximum land usage. The layout of
an AGV equipped terminal is specifically designed with waiting bays on
the apron to ensure a sufficient number of AGVs to maintain STS crane
productivity. AutoShuttles do not require such spaces or waiting time
and, in addition, the smaller fleet of vehicles required reduces traffic
congestion.
ELECTRIC POWERED HORIZONTAL
TRANSPORTATION
10. CONCLUSION
18
When selecting a horizontal transportation solution for the modern
container terminal, the choice to convert to an all-electric solution needs
careful consideration. When calculating the total cost of ownership,
many new factors need to be taken into account, as well as old criteria,
such as the type and number of vehicles, which can take on a new
meaning in the green terminal. Improving throughput by decoupling
ship-to-shore and yard operations reduces operational compromise
and allows each type of equipment to operate at its own optimum
speed and best performance.
The new battery technology described, only recently applicable to
industrial applications, is under rapid development helped in part by its
ready acceptance in public transportation.
The information contained in this document
represents the current view of Cargotec on the issues
discussed as of the date of publication. It should
not be interpreted to be a commitment on the part
of Cargotec and no guarantee is given concerning
the accuracy of any information presented after
the date of publication. This White Paper is for
informational purposes only. CARGOTEC MAKES NO
WARRANTIES, EXPRESS, IMPLIED OR STATUTORY,
IN THIS DOCUMENT. Cargotec may have patents,
patent applications, trademarks, copyrights, or other
intellectual property rights covering subject matter in
this document. The furnishing of this document does
not give you any license to these patents, trademarks,
copyrights, or other intellectual property. All
trademarks are property of their respective owners.
© 2015 Cargotec. All rights reserved.
Kalmar
Porkkalankatu 5
FI-00180 Helsinki, Finland
tel. +358 20 777 4000
www.kalmarglobal.com
kalmar@kalmarglobal.com
Kalmar, part of Cargotec, offers the widest range of cargo handling solutions and services to ports, terminals, distribution
centres and to heavy industry. Kalmar is the industry forerunner in terminal automation and in energy efficient container
handling, with one in four container movements around the globe being handled by a Kalmar solution. Through its
extensive product portfolio, global service network and ability to enable a seamless integration of different terminal
processes, Kalmar improves the efficiency of every move.
Was this manual useful for you? yes no
Thank you for your participation!

* Your assessment is very important for improving the work of artificial intelligence, which forms the content of this project

Download PDF

advertising