Racecourse-class minesweeper

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HMS Plumpton
Class overview
NameRacecourse class
Operators Royal Navy
Succeeded byHalcyon class
Built1916 & 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)
Length235 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)
Draught6.75–7 ft (2.06–2.13 m)
PropulsionInclined compound. Cylindrical return tube. 1,400 hp (1,000 kW).
Speed15 knots (17 mph; 28 km/h)
Range156 tons coal
Complement50-52 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.

Initial design[edit]

At the start of the First World War, it soon became clear that a large number of minesweepers would be required to keep coastal shipping routes free from naval mines that were laid at night by fast German minelayers. Initially, requisitioned trawlers were used for the task, but they had too deep a draught to operate in some areas, and could be too slow to sever the mooring cables of the mines. Late in 1914, the Admiralty hired a number of paddle steamers which were built to carry tourists to seaside resorts or on pleasure cruises. They were significantly faster than the trawlers and had a shallower draught. Although unable to operate in rough seas, they were judged to be the best solution to the problem and a requirement was issued for a purpose-built class based on the PS Glen Usk, a Bristol pleasure steamer. Because of their size and simplicity, they could be built in small shipyards without affecting the production of larger warships.[1]

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.

Improved Racecourse type[edit]

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.

Notes and references[edit]

  1. ^ Crossley, Jim (5 October 2011). "3. German minelaying and the British response". The Hidden Threat: Mines and Minesweeping Reserve in WWI. Barnsley: Pen & Sword Maritime. ISBN 978-1848842724.
  2. ^ a b Plummer, Russell (1995). Paddle Steamers At War 1939-1945. GMS Enterprises. p. 12. ISBN 1-870384-39-3.

External links[edit]