THIS year two motor life-boats of a new, experimental type have been com- pleted and stationed one at Wells, Norfolk, and the other at Ilfracombe, Devon. They are a surf type, and are 2J tons lighter than the light 35 feet 6 inches self-righting type, up to the present the lightest in the Institution's fleet.

The surf type is 32 feet by 9 feet, and on service, with crew and gear on board, weighs only 4j tons. She is divided into five water-tight compart- ments and has eighty-seven to ninety- six air-cases. If a sea breaks on board she can free herself in six seconds. She has two 12-h.p. engines in a water-tight engine-room, and the engines them- selves are water-tight, so that they could continue running even if the engine-room were flooded.

The surf life-boat stationed at Ilfracombe has the ordinary screw- propellers. The one stationed at Wells has Hotchkiss internal cone propellers.

These consist of a pair of impellers worked by each engine. Each im- peller is in a conical casing and works like a centrifugal pump, drawing the water in at one end of the cone, whirling it round, and expelling it at the other end. It is by the jets of water so expelled that the boat is driven along.

This is a development of the method of hydraulic propulsion used in the early steamer life-boats, of which the first was built in 1888. These boats were propelled by a powerful steam pump which drew in water through an opening in the bottom of the boat and discharged it at the sides.

The Ilfracombe boat, with screw propellers, has a speed of 7 knots, and carries enough petrol to be able to travel 56 miles at full speed without refuelling. The Wells boat, with Hotchkiss internal cone propellers, has a speed of approximately 7 knots and carries enough petrol to be able to travel 50 miles at full speed without refuelling. Both boats carry a crew of seven and can take fifteen people on board in rough weather.

Both boats are experimental, and from the experience gained with them it will be decided which method of pro- pulsion to use in future boats of the surf type..