K + M Class Submarines

These fascinating vessels were designed by the Royal Navy for a specific tactical objective: to have submarines fast enough on the surface to accompany the battle fleet in action. The intent was that they could be deployed during battle as a sort of 'mobile minefield' and so wreak havoc on the German fleet. The result was the K-class submarine.

To obtain this goal, they were propelled by steam- with boilers and funnels. They were also much larger than the usual submarines, and were in many ways ahead of their time.

Not surprisingly, they were not successful in practice, and the classic quote is said to be:

I say, Number 1, my end is diving, what's your end up to?

While still under construction, four were dramatically altered into the M-class submarine monitors - armed with 12-inch guns, taken from old pre-dreadnought battleships. The M's reverted to diesel engines while on the surface, and were otherwise quite different from the K-boats.

The 12" gun of the M-class was not intended as a means of dealing with enemy battleships. Torpedoes were notoriously unreliable, and very few were carried. Large calibre gunfire, at close range, could quickly sink an enemy merchant ship - and so the M-class were born. These guns could not be fired when completely submerged, but could be used with the muzzle above water.

Neither class was particularly successful, the K's in particular being very vulnerable to accident. Post-war, the K-class were quickly scrapped. Of the three M-class, one was converted to a submarine aircraft carrier, the other to a very large, submersible minelayer.

The best sources on these behemoths is:
The K Boats, by Don Everitt (George G. Harrap & Co, 1963), for the K-class submarines, and
M-class Submarines, by Martin H. Brice (Outline Publications, 1983).

From Dave Shirlaw (dshirlaw@TELUS.NET), February 2002:

Two memorials for a jinxed class of World War I submarine have taken place in Scotland:

The eight men rescued by K7 [after the "Battle of May Island"} were the only survivors - 103 officers and ratings died. These men are now permanently remembered by the cairn in front of the lifeboat house at the village of Anstruther.

The annual service took place at Faslane cemetery for the 32 men who died K13 was lost during trials in the Gareloch in 1917.

The retiring National President of the Submarine Association, Rear Admiral Tony Whetstone, completed his final duty by laying a wreath.

Wreaths were also laid on behalf of the Royal Navy and serving submariners, and Argyll and Bute Council.

Cadet Ross Stobo and Ordinary Cadet Kelly Court volunteered from TS Neptune, the Helensburgh Sea Cadet Unit, to take on the task of sounding the K13 bell every second for each man who lost his life that day.

In memory of a later incident, the Royal Navy and Fife Regional Council dedicated a cairn in Anstruther harbour on behalf of the men of the submarines K4 and K17.

Length Overall: 338 ft

Beam: 26 ½ ft

Displacement (surface): 1,880 tons

Displacement (submerged): 2,650

Max Speed (surface): 24 knots

Max Speed (submerged): 9 knots

Endurance Submerged: 80 miles at 2 knots

Armament: 8 18" torpedoes, 2 4" guns

Length Overall: 296 ft (M-1), 295 ft 7 ½ in. (M-2), 303 ft (M-3, M4)

Beam: 24 ½ ft

Displacement (full load, surface): 1,722 tons

Displacement (normal, submerged): 1,946 tons (M-1), 2,034 (M-3)

Max Speed (surface): 14 knots

Max Speed (submerged): 8 knots

Endurance Submerged: 80 miles at 2 knots

Max Experienced depth (M-2): 239 feet

Diving Times: 16 ft - 1' 30" (M-1); 30 ft - 2' 44" (M-1); normal to periscope - 1'20"

Armament (as monitor): 1 12-inch 40 calibre Mark IX gun (50 rounds ammunition), 4 18" torpedoes plus 4 reloads

HM S/M M-3

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