14-in Mark IX Torpedo (UK)

File:ARTS1893

14-in R.G.F. Mark IX Torpedo

The 14-in Mark IX Torpedo was a British torpedo manufactured by the Royal Gun Factory at Woolwich.

It was to enjoy an uncommonly long stint as the Royal Navy's 14-in torpedo, from 1896 to 1898.

Development and History

The design was submitted and agreed to after changes were applied in December 1891. An overarching goal of the design was to incorporate lessons taken from manufacture of the new 178-in models. The body shape was the same as in the Mark VIII model, but the tail fins were to be like those of the new 18-in long R.G.F. model which could better pass through nets. Overall, its design was described as being different in 10 points from the Mark VIII's, and a pound lighter when charged (705 versus 706 pounds).

The Admiralty stressed there was no hurry to have this new torpedo, as the coming year's small order could just be more of the Mark VIII design. They also asked that the idea of enlarging the warhead by fitting a bluffer head be considered, as these were proving the better shape anyway. It was understood that this might increase weight to about 750 pounds.

They provided sketches of a model with these features with a warhead of 112 pounds. Order and manufacture of two articles was made in 1892.

At the end of 1895, they were just ready to come into service.

Particulars

The final design is extensively laid out in the Annual Report of the Torpedo School, 1895.

The diameter was precisely 14 inches, but the spec allowed 14.015 inches, uncharged, as a maximum. It carried a charge of 79 pounds dry guncotton, 90 when wetted.

With pistol but without air: weight 696 pounds, metacentric height 0.5 inches and C.G. 99.52 inches from end of screw shaft. When charged with 28.5 pounds of air, C.G. is 100.43 inches from end of screw shaft. The pistol projected 4.35 inches with a left-handed fan which was 5 inches tip-to-tip. The warhead was cissoid shaped, 26.1 inches long, of sheet phosphor bronze, and weighed 122 pounds with its 90 pound wet guncotton charge. An exercise head of the same shape, weight and metacentric height of 0.7 inches. It could receive the same Holmes light as the R.G.F. Mark VIII weapons.

Uncharged with pistol, it had a buoyancy of 11 pounds in fresh water. When charged with 28.5 pounds of air with pistol, it was ballasted and adjusted to float horizontally and upright in salt water at a density of 1.026, at 60 degrees F.

The engines 40.884 H.P., delivering 1006 R.P.M. over a 600 yard run. The top fin was 0.148 inches thick, the bottom 0.18 and the sides 0.155. The two steel three-bladed propellors had increasing pitch, mean pitch of 36 inches.

The proof and passing tests were six runs when charged to 1,350 psi:

• two runs from a submerged frame at target 600 yards distant
• two runs from an A.W. tube at least four feet above the water at a target 300 yards away
• one run above water at target 600 yards away
• one run from submerged frame at target 600 yards away

The limits of deviation permitted were:

• lateral deviation from the submerged frame must be less than 9 yards either way throughout run
• from A.W. tube, lateral deviation of 6 yards at 300 yards or 18 yards at 600 yards
• deviation from set depth not to exceed +/- 18 inches

The speeds required were:

• not less than 27 knots in 60 degrees and warmer
• not less than 26.5 knots in 50-60 degrees
• at least 26 knots in water colder than 50 degrees

Endurance was tested in just one torpedo in a batch of twenty, after passing the above tests:

1. make six short runs from above water gun 10 feet or more above water
2. be fired from submerged frame and pass within 10 yards of target at 600 yards
3. it must then "shew no signs of weakness or distortion"

Lastly, one torpedo of every ten was to be tested for interchangeability.

Manufacture and Use

1896

Horsea adjusted the first 69 torpedoes in 1896. They averaged 27.21 knots at 600 yards in 44.7 degree water.

Whitehead-made specimens were passed at Weymouth in three groups, delivering the following average speeds to 600 yards:

• thirty-six torpedoes averaged 27.55 knots in 52.3 degree water.
• thirteen torpedoes averaged 27.90 knots in 57.7 degree water.
• twelve torpedoes averaged 27.31 knots in 48.6 degree water.

1897

Eighty are ordered and are under manufacture at Woolwich.

1898

A small number of these were fitted with Weymouth pattern gyroscopes and issued to ships (e.g., Illustrious and Renown) for evaluation from June onward.

1915

By 1915, at least, these were noted as having 1,600 psi air vessels and a setting of 23 knots to 1,00 yards.

1916

In 1916, it was decided that the warhead of 14-inch torpedoes should be filled with amatol The Mark IXs were to have a 110 pounds of this explosive.

1918

180 of 326 remaining torpedoes were broken up in 1918.

1919

In 1919, it was approved to break up all 14-in torpedoes except for a reserve of fifty each of 14-in torpedo and 14-in torpedo.

See Also

• 18-in Mark IV torpedo, its contemporary