At maximum lowering speed, the brake was applied to test its effectiveness. Heavily stressed parts of the davit and winch structures, as well as welded areas on the deck, were all inspected and passed. The water bags were emptied remotely before the boat was raised to its original position. This procedure must be completed at least once every five years to ensure the integrity of the lifeboats.

The offshore crane onboard the vessel required a 275 tonne load to be applied, as ten percent more than safe working load is needed for proof load testing cranes of this capacity. Eight 35 tonne water bags, rigged with a spreader beam, were used to achieve the load and were filled at a rate of one tonne per minute.

As Water Weights’ Operations Manager, John Parr, pointed out, ‘One of the many benefits of using water bags, rather than traditional solid weights, is that it allows the load to be applied gradually. If a problem with the crane is identified, the filling can be stopped immediately before any damage occurs’. However, no such difficulties arose on the Toisa Polaris and after a thorough examination of the crane operating under load, it was given the all clear. Cranes must undergo proof load testing every four years.

MJ Information No: 19431