Keeping control on the quayside rails

While the hoist brakes may be considered the most important for cargo handling operations, gantry brakes, including storm brakes, must not be overlooked. "Gantry brakes and rail clamp is an area which deserves special attention by terminal operators and their insurance companies, in view of more frequent wind induced collisions and collapse, being encountered," says Portek’s chairman Larry Lam.

Indeed, recent research by the TT Club into the cause of insurance claims shows that quay cranes being blown along their rails is the second biggest cause of weather damage to cranes. Such accidents can be very costly, both in terms of the destruction of the cranes and potential loss of human life, illustrating just how important gantry brakes are.

Lam continues: "Multi-disc motor integrated brakes suffer from poor heat dissipation and limited access to check adjustment and lining wear. They should be replaced with separately mounted thruster disc brakes or calliper brakes. The number of gantry brakes should be increased to 50% of the wheel assemblies, to provide more resistance against runaway condition in the event of a wind gust during crane operation."

According to storm brake specialist Rima, terminals must have a clear idea about the real maximum wind speed to which their cranes may be exposed.

Among recent technical innovations undertaken by Rima, it says it has rationalised the conception of the hydraulic units/cylinder for releasing its series of self-blocking rail clamps, avoiding the use of hydraulic accumulators.

"This is through the use of cylinder dimensioned not on the base of load but on the base of volume to guarantee hydraulic delay," explains Vincenzo Marmorato, Rima’s commercial director.

Marmorato argues that Rima’s self-blocking rail clamps offers a greater level of durability and reliability than traditional spring rail clamps. "Our system, when applied, stands ready to work, without any effect by jaws on rails," he says. "Our system starts working only under the effect of the wind and reacting proportionally to the wind force. Therefore, real working time is very short compared with traditional systems which, once applied, are subject to wear even without wind."