Full hull model of Costain's lifeboat (circa 1840), carved in the solid and built to a scale of 1:16. The clinker hull has a cork fender around the gunwale with rope grablines hanging below. It is fitted with a washstrake at the bow for added protection against spray and was rowed by 8-10 oarsmen. Nine of these lifeboats, with a length of 25ft, 6 ins. and beam of 7ft, 6 ins., were built to the order of the Liverpool Dock Trustees. They were described as being similar to a ship’s pinnace in shape but with a bow and stern alike. Buoyancy was secured by a dozen airtight casks, but the boats were not self righting and had no means of freeing themselves from water apart from bailing.

After 1850, the boats were improved by the introduction of relieving tubes and valves beneath a deck set a few inches above their waterline, and the fitting of side air-cases in place of casks. The clinker hull was also improved with the introduction of double-diagonal planking which provided a lighter and stronger hull.

Although these boats had their weak points, they nevertheless accomplished a great deal of life-saving work, assisting 391 vessels in distress and saving 1,128 lives in ten years of service.