Although we are well into the project, there will inevitably be many changes to the boat before it enters service (many of which we are planning already), so don't be surprised if the FSB2 delivered to station m 2005 looks a little different to what you see here.

SB2 started life as the replacement for the slipway launched Tyne class lifeboats (yes, called FSB11, which will be coming to the end of their 20-year operational life early this century.

In line with our declared operational commitment to provide cover up to 50 miles offshore, the replacement boat is to be a 25 knot all-weather lifeboat with capabilities similar to the Severn and Trent class boats.

As with all new equipment projects in the RNLI, an operational requirement was drawn up to define the intended capability (see right) and, as with all projects, the requirements seem to say 'more, faster, and better than last time'. These requirements reflect the RNLI's drive to provide better kit for our crews wherever we can.

The project so far The technical department began work on a concept design in 1996, and after several months of testing scale models at the Defence Evaluation and Research Agency (DERA) test tanks in Gosport, model number 9 was selected for its sea keeping, efficiency andmanoeuvring qualities as the hull of FSB2. The hull was then developed into a preliminary lifeboat design, which included assessing the self righting capability, powering options and the requirements for crew and survivors.

Having defined the hull and basic design, the RNLI then competitively tendered the final design and build of FSB2 to industry, which culminated in a four-phase contract being placed with Devonport Management Ltd (DML) of Plymouth. DML have employed Green Marine of Lymington, who built the RNLI's Severn and Trent hulls, to manufacture the hull and deck structure for FSB2. The bare hull and deckhouse was shipped by barge down to DML in Plymouth, where it has been fitted out.Operational requirements Inherently self righting Capable of slipway operation and of lying afloat Two or more engines Capable of taking the ground Capable of carrying a Y boat Minimum top speed of 25 knots in fair weather Duration of not less than 10 hours at top speed Capable of remaining on task for four hours in the most severe weather conditions To accommodate seven crew (including doctor) To have seated accommodation for not less than 12 survivorsThe RNLI have included input from over 20 lifeboat coxswains and mechanics from around the coast in the development of the FSB2 design, and crew input will continue to play a major part in the remainder of the project.How is FSB2 different from the Tyne? FSB2 Tyne Length 14m Beam Speed 25 knots 18kno Weight Construction Fibre reinforced material Steel Crew Daughter boat Endurance 10 hours at 25 knots 12 hours at 18 knots The way ahead At the time of writing, the experimental boat (ballasted to represent the intended fit out of a station boat), is undergoing RNLI 'proof of concept' trials in the South West. These trials will establish how the boat performs compared with the predicted results derived from our initial model tests. After these trials, the boat will be taken back into DML's workshops to undergo a metamorphosis, to re-emerge as the prototype boat, which will be fitted with more operational equipment. The prototype boat will then undergo further operational trials.

Providing these trials prove successful, a second boat (known as the pre-production boat) will be built. The aim here will be to resolve snags in the build process to make the construction of the station boats as efficient as possible. In this way all operational and construction issues can be addressed before committing to the final design of the production boat.

The production boats themselves will be built to enter service around 2005, and although the total number of FSB2s required has still to be finalised, around a dozen slipway stations have been identified as firm candidates for FSB2.

Features and benefits • The Y boat. Tynes are fitted with a small inflatable boat which cannot take an outboard • motor. However FSB2's powered Y boat (as carried by the Severn and Arun) is stored beneath the aft deck, ready inflated, with its outboard fitted. It is launched by operating a hydraulically powered door in the transom. The lowered door then provides a stable platform for the crew to deploy the Y boat.

• FSB2 is bigger, faster and more capable than the Tyne, for little difference in weight. The only way to produce the extra speed was to make the boat from a lighter weight material that could also deliver the strength required. So FSB2 is built from fibre-reinforced plastic, usingsimilar materials and processes to those used to manufacture our Severns and Trents.

• Nothing on the boat can be higher than 6m from the keel when she passes under the boathouse door, so the mast is hinged and hydraulically powered, enabling it to be folded back before entering the boathouse.

• FSB2's propellers and rudders are protected from damage by a centre keel and smaller side keels, which are particularly important for a slipway boat as they are used to support the boat on the slipway.

FSB2 is quite a large boat (only 1m shorter than the RNLI's largest boat, the Severn). To make sure that crews can get close to the water to rescue survivors, there is a deck side cut-down area.

The wheelhouse of FSB2 is unusual for an RNLI boat - it doesn't have a wheel! The boat can be steered from either the helmsman's or coxswain's seats by a joystick on the left hand seat arm at both positions. Each of these positions also has throttle controls.

Fibre optic deck lighting systems provide safe lighting without affecting night vision.

At the prototype stage, the boat will be fitted with SIMS (Systems and Information Management System). SIMS is a system under development that will integrate all the boat's electronic systems (ie, navigation, communications, engine management etc) and display this information via any of six flat screens to be sited on board.

SIMS will be covered more fully in a later issue of The Lifeboat & Project plan Experimental boat trials Convert to prototype Prototype trials Build pre-production boat Freeze design Build production boats Boats on station In-service support.