View source for 21-in Weymouth Mark III Torpedo

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The '''21-in Weymouth Mark III Torpedo''' was a heater torpedo built by Whitehead.  The company loaned a single experimental torpedo to the [[Royal Navy]] in 1913.{{ARTS1913|p. 8}}

==Development and History==
At the start of the war, all 21-in Weymouth torpedoes in England were purchased; most were given to foreign-ordered vessels whose tubes could accommodate them.  Among these were two 21-in Weymouth Mark IIIs intended for Turkey.

==Mark III==
The two Weymouth Mark IIIs intended for Turkey (along with eight [[21-in Weymouth Mark II Torpedo]]es) were given to {{UK-Agincourt}}.  Her Elswick type submerged tubes required the Mark IIIs to be sawn off to 6.35m by removing a section at the rear of the head.  Once modified, they had the following characteristics:{{ARTS1914|p. 10}}

They had an extreme range of 10,000 metres and had settings for:
* 41 knots to 1,000 metres
* 36 knots to 3,500 metres
* 27 knots to 6,000 metres

Total weight, all on of 2,697 +/-4 pounds.  Overall length with pistol of 250 inches.  300 pounds T.N.T. warhead.  Air vessel of 18.48 cubic feet and 2,200 psi could take 212 pounds of air.  Water charge 1,696 and fuel charge of 288 fluid ounces.  Double valve Mark I* type depth gear.

==Mark III*==
A single example of this torpedo was snapped up at the start of the war, and was sent to Loch Long for trial.{{ARTS1914|p. 10}}

It was the same as the Mark III above, except as follows.{{ARTS1914|p. 10}}

Total weight 2,912 pounds, all on.  267.72 inch length with 5 inch Weymouth pistol.  330 pounds T.N.T.. Enlarged air vessel of 21.7 cubic feet, holding up to 249 pounds of air when charged to 2,200 psi.

The extreme range was greater, at 12,000m, and the settings were:
* 38 knots to 3,500m
* 25 knots to 10,000m

==Footnotes==
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==Bibliography==
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==See Also==
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{{CatTorpedo|21-in|Weymouth}}