Press Release: TT Club Calls for More Stringent Crane 'Tie-down' Procedures
16 October 2008
Analysis of the TT Club's claims over a number of years has highlighted that wind damage to quayside cranes is the biggest weather related cost to terminals. Due to their size, profile and location on the quayside, these cranes are particularly susceptible to wind, and care must be taken in the design and operating procedures to protect against the crane being blown over or along the rails.
"This type of incident can result in serious injuries to workers and be very costly in repairs and operational downtime," notes Laurence Jones, TT Club's Director Global Risk Assessment. However such incidents can be prevented, or at least the collateral damage caused can be restricted by having appropriate procedures and ensuring that they are followed. Essential elements include: having effective national and local weather forecasting systems and ensuring that operational procedures respond appropriately when sufficient warning is forthcoming. In addition, good practice would dictate that storm pin or tie-down facilities and procedures are invoked. Furthermore, appropriately designed braking systems, which are properly maintained, can significantly help in conditions of sudden wind bursts. There are two major windstorm issues to be considered: protection against forecast strong winds, and protection against sudden local winds called micro-bursts.
In the case of forecast strong winds, storm pins and tie-downs of sufficient number and size to hold a crane structure stationary (and procedures to implement these) are required to protect quayside cranes. Storm pins are vertical sliding pins mounted at suitable positions under each leg of the crane. These pins are dropped into sockets set into the surface of the berth. The pins must be interlocked with the travel motion so that the crane can only be moved when the pins are disengaged.
Storm tie-downs are connections on the crane, normally at the four corners, where suitable slings, chains or bars of appropriate size and number are fitted to connect to anchor points in the terminal pavement. These anchors must be able to hold the loadings of the crane under potential wind conditions.
The other situation of primary danger is the occurrence of microbursts. In the worst circumstances, unknown to the driver, a strong wind arises blowing in the same direction in which the crane is travelling and the driver is unable to stop the motion of the crane. To deal with these situations, suitable storm brakes and service brakes are necessary and should be fitted to the crane. These are not however, an acceptable alternative to pins or tie-downs for forecast weather conditions.
There are a number of different systems used for storm brakes or, as they are sometimes called, parking brakes. These include rail clamps and railhead brakes. However, these are static brakes, ie. they are only applied when the crane has stopped moving. They normally operate if the emergency stop is activated and unless severely damaged will help prevent a stationary crane from being pushed along by the wind. Their main purpose and benefit is to park and anchor the crane between normal operations without the need to apply the storm pins or tie-downs.
If rail clamp and railhead brakes are applied when the crane is moving, both the brakes themselves and the crane rail can be damaged. For this reason, wheel brakes should also be installed; these are normally disc brakes mounted on the crane wheels. Finally, the service braking system forms the normal operating brake. This is part of the motor and gearbox of the crane, which slows and ultimately stops the crane during daily working.
Apart from accurate weather forecasting and adequate technical measures Jones emphasises that both maintenance and training are crucial to safer procedures. "Investigations of these incidents have shown that most were due to, or made worse by, many of the service brakes and park brakes being inoperative due to poor maintenance.
"When a driver is faced with a crane being blown along the quay, the natural tendency in many cases has been for him to try to move the crane back into the wind. However, by doing this the crane service brakes are lifted and become ineffective. The driver must immediately hit the emergency stop, applying the service brakes as well as the storm or parking brakes," explained Jones.
The TT Club urges terminal managers concerned with quayside cranes and bulk loaders/unloaders to review their emergency plans in respect of high wind situations and ensure that all necessary measures have been taken to prevent injury, damage and downtime arising from this cause.
Note to Editors:
The TT Club is the international transport and logistics industry's leading provider of insurance and related risk management services. Established in 1968, the Club's membership comprises ship operators, ports and terminals, road, rail and airfreight operators, logistics companies and container lessors. As a mutual insurer, the Club exists to provide its policyholders with benefits, which include specialist underwriting expertise, a world-wide office network providing claims management services, and first class risk management and loss prevention advice.
For further information please contact:
Ian Lush, Marketing Director, TT Club
Tel: +44 (0)20 7204 2642
Peter Owen, ISIS Communications
Tel: +44 (0)1737 248300