The RNLI’s D class lifeboat 

The D class lifeboat, first introduced into the RNLI fleet in 1963, was designed to be launched quickly and easily so that it could provide a rapid response to a distress call with high-speed transit to the casualty. It is a fully inflatable craft built of a polyester material coated with ‘hypalon’– which is impact and abrasion resistant. The hull is divided into seven compartments so that, should one become punctured, the lifeboat will remain serviceable.

The design of the boat has continued to evolve since it was introduced, however it was completely  re-engineered and updated between 2000 and 2003 following extensive consultation with lifeboat crews. The production version of the new D Class, Inshore Boat 1 (IB1) was introduced in August 2003 with improved performance in areas such as speed, manoeuvrability and equipment fit out.

The new model was the work of the RNLI’s in house engineering team, who are responsible for the design and development of all the lifeboats in the fleet.

The major features and benefits of the new craft are listed below: 

Feature	Previous D class	New D class (IB1)	Improvement
Speed	18-20 knots	25 knots	Faster response
Structure	Marine plywood	Fibre reinforced plastic	Greater strength, lower maintenance and reduced through life costs
Boat fabric	Hypalon coated nylon	Hypalon coated polyester	Gives more consistent boat shape and performance
Navigation	Chart and compass	Chart plotting GPS (Global Positioning System)	Improved navigation capability
Anchor system	Stowed in parts	Ready rigged	Quicker and easier to deploy
Equipment stowage	Distributed around lifeboat	Stowed in dedicated lockers	Equipment is kept dry, organised and secure
Engine start/re-start	Manual	Electric with manual back up	Faster re-start improves safety for crew following capsize
Boat dimensions	Length: 5m, width: 2m, weight: 380-400kg	Same as previous design	Dimensions, shape and weight better controlled to ensure consistent performance