TT Talk - The importance of Quay Crane Boom Anti-collision protection
Fitting electronic sensor devices to all quay crane booms to prevent them accidentally colliding with vessels could save the ports industry millions of dollars of damage and operational downtime.
The TT Club has received over 150 port insurance claims in the last five years resulting from the booms of quay cranes hitting vessels. These collisions vary from minor impacts with the bridge of the ship, to one incident which resulted in around two million US dollars worth of cost by the combination of damage to the crane boom itself and the ship’s crane, as well as major business interruption due to the quay crane being out of service for six months. In total, boom collisions account for nearly 50% of the asset-related cost of incidents involving quay cranes.
The Club has previously provided advice on the need to ensure adequate boom anti-collision sensors are installed. While the number of these incidents per year has been reducing since 2007, it is notable that the costs of this type of insurance claim are trending upward. In order to avoid fluctuation in values, the chart below expresses the costs as a percentage of total crane valuation.
Quay Crane Boom-to-ship Collisions
*It is thought likely that the cost reduction in 2009 is anomalous, reflecting lower use resulting from the financial crisis.
Perhaps unsurprisingly, the cost of repairs to damaged booms and the related impact or downtime has been trending upwards since 2007 – the average then was US$80,000, swelling to nearly US$120,000 in 2010. However, what could be hidden behind these costs is the liability exposure, including injuries. The most likely point of impact in these incidents is some part of the ship’s superstructure. In the Club’s experience, the ship damage, related demurrage and other liabilities amount to almost three times the cost incurred in bringing the crane and boom back into service. Further, as with all claims incidents, the true cost is far higher due to operational downtime and other ancillary losses, including such things as management time diverted from other priorities and the need to keep customers onside. A study by the UK HSE (Health & Safety Executive) found that the ancillary costs or uninsured costs are between 8 and 36 times more than the insured costs.
The TT Club’s latest analysis of insurance claims shows this sort of accident remains common around the world, evidencing that there remain many quay cranes with inadequate boom collision protection. All quay cranes are at risk, including those involved in container, bulk and general cargo operations. Therefore, the Club continues to recommend strongly the installation of effective boom anti-collision systems to assist crane operators in avoiding these incidents.
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 before a collision occurs, and does not provide the level of protection afforded by electronic sensing devices. It also requires high maintenance and is not failsafe. Although this wire system is better than nothing, Laurence Jones, TT Club’s Director of Global Risk Assessment recommends an electronic sensor system.
Electronic sensors can practically eliminate this type of accident, and should be retro-fitted to existing cranes and specified for new cranes. At this stage there is only one type of electronic sensor available in the market that is proven to provide adequate boom anti-collision protection. These are laser-based units supplied by SICK Sensor Intelligence. These sensors allow programming to provide separate warning, slow down, and stop signals to help prevent collisions. Depending on the structure of the boom, SICK can provide different sensors to suit. The latest sensors are simple to install and require minimum maintenance.
SICK have developed three different specialist packages for crane boom anti-collision:
|Port Package||Technology included|
|LMP100-01||2 pcs. LMS111|
|LMP500-01||2 pcs. LMS511|
|LMPLRS-01||1 pc. LDLRS|
It is anticipated that the LMP500-01 package should suit most cranes and circumstances, although the terminal engineer will need to verify this. The package includes two sensors, which are installed on either side of the crane, and all necessary accessories. Installation is straightforward, since the software set-up is configured. For further information see: www.sick.com/group/EN/home/solutions/industries/port/Pages/port_safety.aspx
As one terminal manager where SICK laser sensors have been installed said, 'they provide the required safety and thus represent a lasting investment with a guaranteed future'.
A radar system from Navtech also works effectively but is more costly than the SICK sensor (www.nav-tech.com ). Some other suppliers provide sensor systems that require major structural mounting and utilise other technologies that are not yet proven in this application.
Laurence Jones recommends that all new cranes should include a SICK sensor for boom anti-collision in the tender specification. This forms part of the recently released 'Recommended Minimum Safety Specifications for Quay Container Cranes', published jointly by the TT Club, the Port Equipment Manufacturers Association (PEMA) and ICHCA International. It is additionally important to ensure the electronic sensors are installed correctly, since faulty installations have been identified.
For retro-fitting existing cranes the Club recommends contacting SICK local offices directly to arrange appropriate supply and installation. Additionally, TT Club Members will receive 7% discount on the cost of the sensors ordered through a SICK subsidiary or recognised distributor. Installation is simple and involves bolting the sensors on either side of the boom and running cable to two spare inputs in the control computer (PLC) in the crane electrical switch-room. Total cost excluding PLC inputs should be no more than US$15,000 per crane.
Comparing this cost to the potential cost of asset damage, operational downtime and liability exposure, the laser technology is seen as very worthwhile.