Bulk – Floating crane – Evolution or revolution?

With landside operations becoming increasingly congested and land for expansion limited one solution is for terminal operators to move their operations to the water.

Peter van Schie reports

Moving terminal operations to the water might seem a silly idea but there are a lot of benefts to be gained.A case in point was the’battle’ that was raging in the port of Rotterdam, the Netherlands around 18 years ago, where two terminai operators -one was operating land-side bulk handling equipment while the other was operating floating grab cranes – were vying for the business of the same clients.This battle also affected the Port as it saw no income from the floating cane operator as the ships were not mooring at a berth but were unloaded mid-stream – something that was (at that point) unusual for the Port of Rotterdam.

Over the years, terminal openton have been looking at ways to reducing congestion, pollution, lowering (operational) costs, enhancing efficiency and productivity by moving their operations ‘somewhere else’.

For the container industry this has resulted in two plans that might see container operations take to the water (see JanIFeb 2006 issue – Floating an Idea article). The first plan included one single container crane placed on a barge in support of another land-side based container crane. The two cranes would ‘sandwich’ a container vessel and work from both sides to load and unload containers. Such a concept is similar to the Amsterdam Container Terminals (previously known as the Ceres Container Terminal) in Amsterdam, the Netherlands, where 6 land-side based container cranes (3 on each side) tackle the loading and unloading of containers on a vessel that has been ‘parked’ in a slip.

This futuristic concept was designed by Oakland-based Likech and the company has come up with the second suggestion – a Floaterm concept (see Jan/Feb 2008 issue on Crane design) that utilises waterside container cranes on a barge to form, in effect, an offshore wharf. The container ship is moored to the crane barge or vice versa and containers are transferred from the ship to the barge deck or to feeder barges. But both concepts might not be economically viable (specially at the moment with a bleak economical outlook) and there is also the issue of stabilising the barges during operations, for example if the barge is moving too much, the spreader would be swaying making it difficult for the driver ‘to land’ the containers properly or even pick them up.

Bulk Industry

The floating crane story is completely different for the bulk market. Movement of the barge shouldn’t be an issue for the grab (there is no particular place where the grab needs to land) and the floating concept provides an excellent alternative to land-side bulk cargo handling equipment for operators with high throughput of cargoes. It is therefore no surprise that for the last couple of years many mobile harbour cane manufacturers have entered this market, with some coming up with innovative ideas.

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E-Cranes

Another company that has recently sold a floating crane is E-Crane Worldwide, Belgium. The company develops turnkey material handling solutions and is probably better known for their Equilibrium or balance cranes (see Testing Times article – December 2008 lssue). Their cranes differ from the standard MHCs as their design is based on an ingenious parallelogram style boom that provides a direct mechanical connection between the counter-weight and the load. This unique system ensures that the crane remains in near perfect balance throughout its working range. Compared to conventional cranes that require as much as 80% of their available energy just to move the boom, stick, and grab, the E-Crane® makes gravity work reducing horsepower requirements and power consumption by up to 50% and significantly reducing maintenance and operating costs.

Their fundamental design principal of balance, results in much lower dynamic overturning moments transferred to the floating terminal compared to competing equipment. This benefit results in less barge movement, more precise control of the load, simpler mooring systems and less potential for damage to adjacent vessels or infrastructure. It is therefore no surprise that their concept of a floating bulk handling terminal is well suited for both port operations (ship-to-shore), as well as midstream transfer (barge-to-ship and ship-to-barge) and 10 years ago E-Crane® delivered its first barge and ship mounted E-Crane® to offload barges and small ships. The company adapted this concept for the offloading of ships up to Panamax-class and has more than 15 units operating successfully world-wide. They also offer models with up to 50 tonnes duty cycle capacity due to their movable counterweight and fixed parallelogram linkage.

In the second half of 2008, the company delivered a mid-stream transfer station for Seaboard Corporation, USA, for their Midema (Minoterie De Matadi) flour mill in Matadi, Democratic Republic of Congo. The floating trans-loading station, the 1000m2 barge Mama Mobokoli was equipped with a 1500B-Series E-Crane®, designed and built in Belgium,and reached the grain terminal in Matadi after a 40-day ocean going voyage. The floating terminal is designed for ‘ship-to-quay’ discharging of handy and handy-max vessels (25,000 to 30,000 tonnes) with ‘ship-to-ship’ and ‘midstream tans-loading’ capabilities of break bulk commodities on the Congo River.The crane has a reach of 35.9m, lift capacity of 13.5 tonnes and a 400 tonnes/hour unloading capacity for handy-class vessels. To unload the ships, the floating terminal is towed alongside and secured to the ship, then using its winches to move along the ships. The crane transfers grain from the ship into two hoppers, a conveyor then transports the grain directly to the silos.

E-Crane® has also been involved with PowerSouth for their coal handling terminal to offload coal from incoming barges at their Charles R Lowman Power Station in Leroy, Alabama. The centre-piece of their coal handling system is an all-electric E-Crane®. It has the ability to load 1,500 tonnes of coal per hour with only 450 kilowatts of installed power. The crane has been assembled, is on-site and will be operational this month.

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Conclusion

The manufacturers we spoke to were in agreement that the use of floating terminals for bulk cargo handling will increase over the next couple of years as more and more terminal operators become aware of the benefits of the floating crane. Its independence of quay facilities and mooring places could solve a lot of congestion issues in ports and harbours around the world. The variety of options and the possibility to tailor-make the design is a plus for many potential clients as the crane can be tuned to meet specific requirements including being self-propelled, fit with sheltered area for steel products, heavy lift, larger storage capacity, etc. Finally, there is scope for similar floating terminals for containcer handling operations but this seems to be “just a dream” – for the moment.

Source: World Port Development , March Issue – 2009