The company’s ship-lifting system in Dubai Maritime City

WITH high precision and in the most difficult conditions, specialists from Bosch Rexroth are able to hoist ships weighing many tonnes out of the Arabian Gulf in Dubai. Specialised technology provides protection from sand, seawater, and high air humidity, as high-precision drive mechanisms distribute the ships among more than 40 mooring areas.

It took just one-and-a-half years for Bosch Rexroth’s specialists to build in Dubai the largest ship-lifting platforms in the entire region – under the most demanding conditions. “In summer, the temperature rises to 50 degrees Celsius,” explains sales manager Hans van Herwerden, “which is a real challenge for both people and material.”

 The facility is part of Dubai Maritime City, an artificial peninsula with an area of 2 sq km off the coast of the UAE.  It is located on the banks of one of the concrete bays. It comprises a track system with two large ship-lifts, one 90 m in length, the other 130 m.

The two platforms now lift ships weighing up to 6,000 tonnes out of the Persian Gulf. By way of an integrated transfer system these ocean bound giants are brought over metal carriages to one of the 42 berths and repair stations within just two hours.

 

SHIFT LIFTING SYSTEM

Platforms: The larger of the two platforms must sustain loads of up to 6,000 tonnes. The giant platforms themselves have an enormous mass. The smaller, 90 m long and 25 m across, weighs 1,200 tonnes and sustains loads of up to 3,000 tonnes. Both of the platforms are 3.5 m high and can lift ships with drafts of up to 9 m out of the water and lower them back in. These tasks can be accomplished at a rate of 30 cm per minute.

Winches and Motors: Fourteen winches raise and lower the smaller platform; twice as many are used in the larger unit. Assuring that ships cannot slip, the winches are calibrated for the highest precision; the maximum deviance is less than one-tenth of a millimetre. Two brakes are each capable of bearing a maximum weight of 375 tonnes, and further assure operating safety. The winches are driven by maintenance-free servo motors, which are ideally designed for extreme climates. They produce a torque of up to 150 Nm and command high power reserves. The 42 drives generate a cumulative output of 1.8 MW.

Control centre: The control centre affords a full view of both basins. Once the ships are securely anchored, it takes the single push of a button to set their enormous loads in motion with millimetres’ precision.

The dedicated software allows complete control over the 42 mooring winches. The computer display allows the controller to keep track of the differing loads on the motors as the payload is lifted or lowered. The two ship lifting systems have a capacity of 750 ships in a year, meaning 1,500 lifting operations.