Non destructive testing on vital vessels puts RNLI's mind at rest

Case Study

Lifeboats of the Royal National Lifeboat Institution (RNLI) operate in some of the most demanding sea conditions imaginable. The RNLI designs and tests its lifeboats accordingly. However it is not surprising that, on occasion, the vessels suffer damage as a result of operating in these conditions. The RNLI consulted TWI when a very heavy slamming impact caused damage to the structure of one of the charity's Tamar class lifeboats.

The RNLI planned to make use of non-destructive testing techniques to assess the damaged area, both before and after repairs. They particularly wanted to evaluate alternative methods to provide additional information on the condition of the solid glass fibre reinforced epoxy hull. With TWI's assistance, pulsed thermography was used. While some of the hull stiffening had disbonded from the hull and suffered damage due to high local deflections, the non destructive examination proved that no damage had been caused to the hull itself and therefore limited the amount of material that had to be removed. The damaged stiffening was subsequently repaired and the lifeboat returned to service.

Results provided useful information and demonstrated to the RNLI the benefits of using pulsed thermography techniques.