TT Club said it has received more than 100 claims in the past two years resulting from the booms of quayside cranes hitting vessels. These collisions vary from minor impacts with the vessel bridge to one incident that cost about $2 million through the combination of damage to the crane boom and the vessel's crane, as well as major business interruption due to the quayside crane being out of service for six months.
The total cost of claims of this nature reviewed by the club was in excess of $12 million. This figure reflects just the physical damage aspects and does not account for the significant injuries that often occur. And, as with all claims incidents, the true cost to operations is far higher due to operational downtime and ancillary costs, including such things as management time diverted from other priorities and the need to keep customers onside.
TT Club's latest analysis of claims shows this sort of accident continues to be common at many terminals around the world. Laurence Jones, TT Club's director of global risk assessment, says all quayside cranes are at risk, including those involved in container, bulk and general cargo operations.
Mr Jones said: We strongly recommend the installation of effective boom anti-collision systems to assist crane operators in preventing these incidents. Modern electronic sensors today can practically eliminate this type of accident. They should be retro-fitted to existing cranes and specified for new cranes.
For a cost in the region of $10,600 per crane this is a very worthwhile investment. Sensors have been shown to be very effective and a great deal of damage and loss can be prevented for a relatively small investment.
Technical note
There are two types of sensor systems currently in use. The simplest consists of wires run along the length of the crane boom, which activate a switch to stop the crane if the wires are touched. However, this system may not completely stop the crane fully before a collision occurs, and does not provide the level of protection afforded by electronic sensing devices. Although this wire system is better than nothing, an electronic sensor system is recommended.
At this stage there are only two electronic sensors available in the market that can provide boom anti-collision protection. One is a laser-based unit supplied by Sick Sensor Intelligence and the other a radar-based unit from Navtech Electronic Ltd. These sensors allow programming to provide separate warning, slow down and stop signals to help prevent collisions. Depending on the structure of the boom, one or two sensors may be required.
The sensor units need to be kept clean, so the installation should allow for easy access. Also, a substantial mounting system is important to ensure vibration does not fatigue the mounting or cause operational errors. The laser sensor can be affected by extreme dust, rain and fog, while the radar system works in all conditions and is probably the best unit but is more expensive than the laser.
For more information on the sensors visit
http://www.sick.com and http://www.nav-tech.com.
