Racecourse class minesweeper

HMS Plumpton
Class overview
Name:	Racecourse class
Operators:	Royal Navy
Succeeded by:	Halcyon class
Built:	1916 & 1918
Completed:	24 Racecourse class 8 Improved Racecourse class
General characteristics
Displacement:	Racecourse-class: 810 long tons (823 t) Improved-class: 820 long tons (833 t)
Length:	235 ft (72 m)
Beam:	Racecourse-class: 29 ft (8.8 m) Improved-class: 29 ft 3 in (8.92 m) 58 ft (18 m) at the paddles (both types)
Draught:	6.75–7 ft (2.06–2.13 m)
Propulsion:	Inclined compound. Cylindrical return tube. 1,400 hp (1,000 kW).
Speed:	15 knots (17 mph; 28 km/h)
Range:	156 tons coal
Complement:	50-52 men
Armament:	Racecourse-class: 2 × 12-pounder guns Improved-class: 1 × 12-pounder gun 1 × 3-inch AA gun

The Racecourse-class minesweepers were 32 ships delivered to the Royal Navy during the First World War. They were built to two related designs as paddlewheel coastal minesweeping sloops under the Emergency War Programme. The vessels were reasonable sea-boats, but lost speed badly in a seaway when the paddle boxes tended to become choked with water. The class is also widely referred to as the Ascot class and Improved Ascot class.

The original design was by the Ailsa Shipbuilding Company. The ships were completed between April and October 1916. Launch dates are shown below.

On this type the foremast is stepped before the fore bridges and have derricks abeam of the second funnel.

These paddle minesweepers were designed by the Admiralty, adapted from the Ailsa Company design for the first type. They were completed between January and June 1918. All were built under the Emergency War Programme.

The foremast on this type is stepped through the chart house, there are two high ventilators abaft fore funnel and no derricks abeam of the second funnel.

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