Equipment manufacturer Buhler is a major supplier of
mechanical ship unloaders, as well as many other products
including pneumatic handling equipment, grain storage solutions
and conveying components for grain-related industries.
The use of mechanical ship unloaders is sometimes preferred
over pneumatic equipment, as it can offer ‘soft’ material
conveying, not possible at the high speeds of pneumatic
Mechanical unloaders also offer high throughput, and better
availability and durability. Energy consumption is also lower.
Buhler’s equipment is used to handle all dry agribulk
commodities, from grain to soya, rice to maize. It is also used
with mealy products, oilseeds, pellets and derivatives. Its ship
unloaders handle all the products used in the industries of
Buhler’s Grain Processing business units (grain milling, feed,
biomass, sortex, rice and malting).
Buhler has optimized its mechanical unloaders (chain
conveyors), so that no material remains in the conveyor. This is
a huge step as it was long considered that pneumatic unloaders
were the only ones where no material remained in the piping.
Buhler chain conveyors are optimized to have no ‘dead’ zones
and therefore fulfil similar sanitation requirements to pneumatic
During operation, a mechanical unloader can reach not only
under the deck rim, due to its kick-in/kick-out function, but it
also does not lose capacity because its geometry is always the
same, consequently performance is always the same.
Looking at unloading in three phases, the mechanical unloader
can run at full capacity during phase one with automatic sink-in
feature, during phase two with kick-in and kick-out. Only during
rest-unloading does the throughput decrease.
Pneumatic unloaders can be considered to have the
advantage during the final clean-up stage, as they work rather
like a vacuum cleaner. Nevertheless, throughput during this final
clean up is drastically below maximum capacity. In fact, most
customers do use the help of front-end loaders during final
clean-up even when unloading with pneumatic systems. For
mechanical unloaders, the use of these loaders is standard
Another advantage of the mechanical unloader is its stronger
hoist, it can bring loaders up to a weight of 15 tonnes into the
ships hatch; the pneumatic unloader would require a separate
crane for this task.
Using mechanical unloaders means that there is less wear and
tear on the equipment. Noise levels are also generally about
10dB lower using mechanical equipment.
Buhler’s unloader product range includes the Portalink and the
Portalino, both of which are also available as combined
loaders/unloaders. This is an advantage for customers that
receive material by ship, process the material and then distribute
again by ship. The final distribution can be the processed goods
themselves, or even by products, such as DDGS (distillers dried
grains with solubles).
The Portalink. This mechanical ship unloader from Buhler is
designed to handle a wide range of free-flowing bulk materials.
From evaluation and simulation of the optimal unloading process
to design and engineering, structural analysis, manufacturing,
installation, and start-up, the customer’s entire project is handled
by one single, competent and experienced partner. This enables
the influence of individual parameters on overall performance to
be clearly assessed and evaluated, contributing significantly to
optimizing it.
Regular servicing and genuine spare parts guarantee a high
availability of the installation over many years of service. The
Portalink high-capacity marine leg (HL-SKT) allows the intake
boot to maintain the optimal position inside the bulk material. It
also enables automatic unloading down to the minimum bulk
material level inside the ship’s hold.
The possible movements of: displacing the ship unloader;
lifting, lowering, and swivelling the boom; and kick-in/kick-out of
the marine leg provide a large working range inside the ship’s
hold. These movements can also be remotely controlled by
radio, increasing unloading throughputs and reducing berthing
The Portalino. This is a mechanical ship unloader designed for
efficient unloading of grain, oilseeds, derivatives, and non-freeflowing
bulk materials.
Its unloading throughputs are as high as 330tph, depending on
the flow characteristics of the bulk material. The Portalino is
distinguished by its high degree of mobility and availability as well
as by its outstanding cost-to-benefit ratio.
The Portalino is a self-propelled or stationary mechanical ship
unloader powered by a diesel or electric drive. It is best suited
for use unloading ship sizes of 20,000dwt to 40,000dwt.
Rail-mounted or steerable rubber-tyred travelling gears are
available. The Portalino is used wherever existing quay facilities
do not allow any permanent installations.
The material unloaded is transferred to downstream
conveying systems or directly into rail or road vehicles.
One strength of Buhler mechanical ship unloaders and loaders lies in the
rugged, durable design of the chain.
The chain is a key element for a long lifetime and low maintenance of the
unloader. The Buhler chain links are drop forged, machined and then heat
treated to ensure best part tolerance and uniform hardness of the link.
Various design forms guarantee best conveying behaviour for the different
products. The Buhler chain comes with pull force of up to 120kN.
A new option for the Portalink mechanical ship unloader is the
Portablade (see picture, right).
The Portablade clearing shovel creates clear space for clean-up frontend
loaders and similar tools insidethe ship’s hold. A hydraulic system moves
the shovel to theclean-up position.
Then the operator can clear part of the bottom of the ship’s hold with
the kick system of the marine leg and then lower the front-end loader
with the unloader’s winch into the hold. This is an easy and efficient
way to make way in the hold.
Simultaneously with the celebration of Buhler’s 150-year
anniversary, the Grain Handling business unit has launched its 3D
animation system at the new test facility in the Grain Technology
Center in Uzwil. This technology allows grain processing plants,
ship unloaders, and stand-alone machines to be displayed in a
virtual world even before they are built.
Even functions of the ship unloader’s control system are
integrated into the system, allowing it to be operated. The result
is a simulator enabling Buhler to train customers and show and
explain all features in full detail. It is, for example, quite an
impressive experience to walk at a height of 35 metres above
ground level over a Portalink in the Port of Hamburg.
Customers get really excited about the almost photo-realistic
animation of their specific projects.
Buhler offers a new service to consult clients in their ambition
to optimize the operation and logistics of ship unloading
terminals. The service consists of a detailed analysis of the
existing unloading sequences of the client’s terminal by Buhler’s
specialists and a software-aided simulation which will then bring
up proposals to minimize the tie up time and to increase the
The software application shows the optimal unloading
processes in a system. Existing terminals can improve their
unloading times by determining the best possible hold unloading
sequences, giving consideration to the ship’s inclination and the
existing unloading equipment. The travelling distances of
unloaders are optimized and their throughput capacities are
when possible utilized to the full. In new terminals, it is possible
to clearly show the influence of different system layouts and
individual machine throughputs. The terminal can be exactly
tailored to the existing requirements.
As tie up costs are immense and heavily increasing when
demand for grain is high, timely investments in the unloading
logistics show a very short pay back time. In close collaboration
with one customer Buhler has been able to optimize the
unloading efficiency by almost 10%. The additional investment
for the Buhler solution was paid back in very short time.
For the first half of 2010 the business unit grain handling has
received a solid base of orders and managed to expand its
business activities after an already successful 2009. Mechanical
shiploading and unloading is going very strongly, especially in Asia.
Mechanical continuous barge unloader forms part of TKF eco-coal plant
A mechanical continuous barge unloaders (CBU) is an integral
part of an environmentally friendly coal handling plant to be
supplied by ThyssenKrupp Foerdertechnik (TKF).
In February this year, TKF’s Business Unit Materials Handling,
Germany, was awarded a contract to design and supply a coal
handling plant; including a continuous barge unloader (CBU), a
circular stacker and reclaimer system and the pertaining belt
conveyor system. The order was placed by PT. Inti Karya
Persada Tehnik (IKPT) on behalf of Pupuk Kaltim (PKT), a key
player in the fertilizer industry of Indonesia for the boiler plant
of Bontang Fertilizer Complex in Kalimantan, Borneo.
Already at the stage of concept design of the coal handling
system, technical developments in the field of ship unloading, coal
storage and conveying as well as the following environmental and
economic aspects were taken into consideration:
  •   increasingly strict regulations in the field of environmental protection;
  •   high-performance unloading and handling under different geometrical and meteorological conditions;
  •   high operational efficiency, resulting in cost savings for ship berthing time and operation of the handling plant; and low maintenance and spare parts costs.
Based on this, the following equipment was selected by the end-user and the EPC (engineering, procurement and construction) contractor favouring high efficiency, environmental protection and operation safety and effectiveness:
  •   chain bucket elevator type continuous barge unloader (CBU) instead of grab type barge unloader;
  •   fully covered circular storage with circular stacker and side scraper reclaimer, with full automatic operation; and
  •   covered belt conveyor system for environmental and weather protection.
For this project TKF developed a new generation of CBU
which will fulfill all requirements in respect of unloading
efficiency, environmental protection and low operation and
maintenance cost.
The CBU will be designed for a design unloading rate of
700tph (tonnes per hour) of coal from barges ranging from
7,000dwt to 10,000dwt. The CBU will be of heavy duty design
and construction to operate for a continuous period of 18 hours
per day and an annual period of 330 days. The machine consists
of a rigid supporting frame construction on wheels, which is able
to travel along the length of the barge. Reclaiming is done by a
chain bucket elevator, hinged onto the slewing and luffing boom.
While reclaiming in either longitudinal direction of the barge, the
bucket elevator can be positioned sideways of the boom against
the coal pile on the barge for effective reclaiming. From the
bucket elevators the coal is transferred directly to the boom
conveyor, which in turn feeds it to the portal conveyor. The
operation is controlled from the operator’s cabin or from the
pier by remote control. Digging depth, speed of the reclaimer
and/or traversing is controlled automatically to achieve the
required unloading capacity. The reclaiming is achieved in semiautomatic
mode, allowing manual positioning and/or operating.
ThyssenKrupp Foerdertechnik’s previous references for
continuous barge unloaders and their excellent track record,
including the recent milestone of a high capacity 4,000tph CBU
to Bontang Coal Terminal, were deciding factors in the contract
being awarded to TKF. This special design of the continuous
barge unloader is the first of its kind in Indonesia, although all
critical components have been proven in continuous barge
unloaders previously supplied by TKF. In all, TKF has already
supplied more than 50 continuous ship/barge unloaders, mostly
to clients in Indonesia, Korea, China, Taiwan, the Philippines,
Malaysia, USA, Great Britain, Spain and Germany.
The environmentally friendly conveyors from the jetty to the
storage dome are totally enclosed in galleries and the transfer
towers. The conveyor system transports the unloaded coal to
the storage area enclosed by a dome. The stacking and
reclaiming system consists of a rotating stacker and side scraper
reclaimer, totally enclosed in a dome. The equipment stacks the
coal in a circular stockpile with an outside diameter of 80m. The
design consists of a slewing and luffing stacker to stack the
material at 800tph, a bent chain slewing and luffing reclaimer for
300tph and a central column which includes a feeding and
discharge hopper. The stacking and reclaiming systems
operate independent of each other.
The stacker is designed to permit discharging material
onto the pile with the discharge point at close proximity
to the top of the pile.
Operation of the reclaimer is designed for both
manual and remote control as well as for fully automatic
The award of the contract to TKF for an
environmentally friendly coal handling system represents
continuity with respect to design, manufacturing,
construction and management for high efficiency and
environmental protection of material handling equipment
and complete systems and also demonstrates the client's
appreciation of and satisfaction with TKF’s performance
to date.
System from 4B Braime Elevator Components transforms veteran unloader
The worldwide manufacturer of Material Handling and Electronic
Components, 4B Braime Elevator Components Limited, based in
Leeds UK, has supplied its state-of-the-art condition monitoring
equipment to one of two veteran ship-unloading system located
at the Port of Tilbury on the River Thames. The port is London’s
major gateway, handling significant levels of diverse cargo
including the importation of paper as the UK’s leading port,
containers, grain, and various bulk handling facilities, all of which
are handled at a number of berths both in dock and on river
facilities. The port’s grain terminal facility handles around 1.5mt
(million tonnes) per year, making it one of the biggest in the UK.
The ship-unloaders, in the form of marine legs are the main
component of two rail-mounted, mobile marine towers installed
on the quayside in the 1960s. Based on the then-well-known
North American ‘Great Lakes’ design, the marine towers are
quite unique within the UK. Although the equipment is over 40
years old and has, since installation, handled many millions of
tonnes of grain, it is still in excellent working condition and is a
key element of the grain operations at the port.
Following a major overhaul of one of the marine legs in
2003/2004 it was decided to bring the condition monitoring
right up to date and the 4B Braime Watchdog Elite system was
chosen to be installed on the marine tower.
The marine leg is an extremely heavy duty, purpose built,
bucket elevator; designed to be deployed into a ships hold in
order to dig into and unload grain cargos to shore. Raising and
lowering of the leg, together with luffing, is achieved through a
winch and rope system controlled by an operator in a cabin
mounted high in the marine tower. The 35-metre-long marine
leg elevator operates at a capacity of 860tph (tonnes per hour),
is fitted with 4B Braime HDPE CCS elevator buckets bolted to a
continuous 1,120mm wide belt and runs at a speed of 3.5
metres per second. Although 4B Braime Watchdog Elite elevator
monitoring systems have been around since 1984 and over 2,000
systems have been installed, this is the first to be fitted to such a
mobile device.
So what is the Watchdog Elite system?
Fundamentally all bucket elevators are at risk during normal operation,
regardless of the product being conveyed, because of a number of
issues. These include possible bearing and drive faults, misaligned
head and tail pulleys, belt slipping and rubbing and bucket damage and
rubbing. Together with the potential for inlet & outlet chute
blockages common with any conveyor and the prospect of poor
maintenance and housekeeping due to inaccessibility or lack of
personnel, it is clear why comprehensive monitoring solutions
are necessary. If, in addition to this, the product being conveyed
is combustible or even explosive then monitoring is absolutely
essential! The installation cost of the system is insignificant
when compared to the consequences if workers, plant and
equipment are not adequately protected and a failure occurs.
The Watchdog Elite effectively mitigates these risks by
constantly monitoring a number of conditions. These include
belt speed, belt alignment, bearing temperature, pulley alignment,
blocked chute detection and acceleration. Up to 4 digital and 6
analogue parameters can be monitored and all data is collated at
the Watchdog Elite control unit and monitor (shown above).
The control unit is usually mounted adjacent to the conveyor or
is sometimes positioned in the operators control room.
Capable of running on voltages ranging from 12V DC to
240V AC, the IP 66 rated unit has a LCD
screen that displays machine status
messages (available in four languages), and a
super-bright LED display that shows belt
speed. Calibration and set-up parameters
are accessed via a password and front panel
touch buttons. An optional PLC interface is
At Tilbury the following conditions are
constantly watched:
  belt under speed and misalignment are
monitored by WDA High Power sensors which detect moving
ferrous material, in this case bucket bolts — since non ferrous
elevator buckets are being used. This is a non contacting
extended range sensor, designed to detect targets which are up
to 100mm away. Sensors mounted either side of the marine leg
casing monitor belt alignment.
  alarms for under speed are set at > 10% for 180 plus seconds
and immediate shutdown at > 20%.
  all four main conveyor shaft bearings are monitored for
temperature with trips set at 80°C and alarms for 180 seconds
and real-time readouts are given from 50°C to 120°C.
Blocked chute detection is provided in the infeed chute by
the installation of a Binswitch capacitance style sensor that can
detect plugs. All Watchdog Elite systems are approved for use in
hazardous environments including ATEX Zones 21 and 22 in
Europe, CSA in the USA and Canada and IECEx on a worldwide
basis and the WDA sensor is approved for use in ATEX Zone 20.
All the sensors employed have been developed by 4B Braime
over the last 25 years and are renowned for their ruggedness
and reliability.
The system at Tilbury has been installed since 2004 and has,
to date, been constantly reliable — even though most
components are constantly exposed to an unforgiving marine
environment. No components have been replaced during this
period. Over the six years a number of potential
incidents have been avoided due to the early detection and
quick response capability of Watchdog Elite.
These occur maybe three or four times
per year and are mainly due to belt misalignment. This has given
the operator the opportunity to re-align the elevator belt
without incurring further damage. Whilst the Watchdog Elite is a
‘Guardian’ system, constantly monitoring for a change condition
indicating a potential performance failure, the Port of Tilbury
actually use the information in a quite sophisticated way. Andy
Lamb, engineering manager at the Tilbury Grain Terminal,
explains: “When the Watchdog gives us a first indication of belt
slip and raises an initial alarm, we use this as a ‘trigger point’ to
deploy our planned maintenance scheme. There is a strong
correlation between that very early, slight ‘out of order’
condition and the timing of a service. By doing this our
maintenance regime is tied to hours of machine usage not
absolute time and therefore we only service when necessary.
This saves valuable manpower resources and obviously money”.
Such has been the success of this installation; the customer is
now looking to replicate it on the second marine leg and in
addition has now decided to extend the Watchdog Elite system
philosophy into the main silo block itself. The technology will be
the ‘big brother’ of Watchdog – the T500 Elite. This system is
capable of monitoring up to 256 inputs every 4 seconds and has
full integration capability with the on-site PLC set up.
Cargotec improves control system on popular mobile
dust-free bulk unloaders
Cargotec’s mobile Siwertell dry bulk ship unloaders offer dustfree
operation and the flexibility of moving the equipment
around a port or between ports; the latest innovation improving
the proven technology offers dual control options.
Faxe Kalk A/S of Denmark has ordered a Siwertell 5000 S
mobile dry bulk ship unloader from Cargotec to handle calcium
oxide at 130tph (tonnes per hour). The minerals company takes
delivery of the screw-type unloader soon, and will use it at the
ports of Faxe Ladeplads and Vejle, which are 235km apart.
Mounted on a semitrailer the Siwertell 5000 S is fully road
mobile and suitable for vessels of up to about 5,000dwt.
“The equipment can be unfolded and ready for operation just
30–45 minutes after arrival at the unloading site,” says Jörgen
Ojeda, Cargotec’s director for mobile unloaders. “It is possible
for one person only to unfold or fold-up the unloader on their
Faxe Kalk’s trailer-based unloader is diesel-powered and
features a dual-bellows system, which can be operated via
wireless remote control or by using a pre-programmed
automatic shifting function. “This will be the first unit to benefit
from the remote control of not only the unloader itself, but also
of the bellows system. We have used remote control systems
on unloaders for many years, but the option of using either
wireless remote control or the automatic shifting function for
the bellows system is a new feature for this product,” Ojeda
says. “The customer chose this particular system from Cargotec
because it needed a mobile unit with well proven technology.
The bellows’ control system with automatic shifting, which
allows continuous unloading to trucks, was also a factor in the
decision making.
“There are now about 100 Siwertell continuous, screw-type
road-mobile ship unloaders in use worldwide, typically handling
commodities such as cement, grain, derivatives, fertilizers and
alumina. “Another recent example is a trailer-based Siwertell
5000 S delivered to Cementos Molins Industrial SA in Barcelona
at the end of 2009. In this case the equipment is used to handle
white cement at 300tph. Factors influencing this customer’s
choice of equipment included the dust-free nature of the mobile
system and Cargotec’s unrivalled experience in this technology”.
Cargotec offers three versions of mobile Siwertell unloader:
the 15 000 S and 10 000 S models as well as the 5000 S.
Unloading capacities range from about 200tph up to 550tph. All
can be mounted on a semitrailer, a pontoon, a travelling gantry
or fixed on a pillar.
A trailer-mounted 10 000 S is designed for ships of up to
about 10,000dwt, and a trailer-mounted 15 000 S for ships of up
to about 15,000dwt. All trailers can be moved by road.
Stationary and gantry-mounted 10 000 S units are suitable for
ships of up to about 15,000dwt, and 15 000 S units for ships of
up to about 20,000dwt.
Cargotec improves the efficiency of cargo flows by offering
solutions for loading and unloading goods on land and at sea —
wherever cargo is on the move. For handling dry bulk materials,
Cargotec provides engineering solutions through its Siwertell
brand, including design, installation and after sales services
Siwertell ship unloaders and loaders are based on unique
screw conveyor technology, in combination with belt conveyors
and aeroslides, and can handle virtually any dry bulk cargo, such
as coal, cement, fertilizer, agribulk, clinker, sulphur and grain.
Cargotec can supply plant and terminal design, ship unloaders,
ship loaders, mobile ship unloaders, mechanical and pneumatic
conveying systems, and storage solutions, all designed to ensure
environmentally friendly and efficient cargo operations.