The ‘Battle’ of May Island

Firth of Forth, Scotland

On the night of the 31st January 1918, two Royal Navy Flotillas departed from the Royal Navy base at Rosyth, Scotland, their mission to conduct an excercise, codenamed EC1, with the Grand Fleet, off the Scottish Orkney Islands.

The route was to travel from Rosyth along the Firth of Forth, passing the Isle of May and out into the North Sea and on to meet the Grand Fleet in Scapa Flow, in the Orkney Islands.

The Flotillas comprised of a large number of battleships and cruisers, nine submarines (K Boats or K Class Submarines) and numerous destroyers, a convoy of warships and submarines that stretched for a distance of over twenty miles.

Memorial for the Battle of May Island

U-Boat Operations

Aware that a German U-Boat may be in the area, the Flotillas travelled at speed along the Firth of Forth both in radio silence and with significantly reduced navigation lights.

Unbeknown to them they were also travelling straight towards a group of armed trawlers who were sweeping for mines in the area, the trawlers being equally unaware of the flotillas approaching them.

Standby Collision Forward, Sound the General Alarm!

On seeing the trawlers, the first two submarines took evasive action, the third in line K14 did the same, however in performing the manoeuvre the rudder jammed and K14 manoeuvred in a complete circle, directly into the path of the last submarine in line, K22 which rammed into it.

Close all watertight doors!

By closing watertight doors, immediate disaster was averted but both submarines were now lying stopped in the water with flooded compartments in the path of the cruisers bearing down on them lights were switched on, flares were fired, and radio silence was broken as calls for assistance went out.

Three of the battle cruisers swept safely past, their wash rolling the submarines violently. The fourth, the ironically named Inflexible however smashed into the K22, bending 30 feet of the submarines already damaged bows at right angles to the hull and shearing off a ballast tank as she rode over her, forcing her under the surface.

As the Inflexible continued on her way in the dark, Submarine K22 returned to the surface, now astern of her and resumed calling for help.


At 8.32 pm HMS Fearless rammed into the K17 just forward of her conning tower. The entire crew of submarine K17 managed to escape in the eight minutes before she sank. Now swimming in the water the crew of the K17 stayed together imagining that with the number of ships in the area they would soon be picked up.

The K6 then met the K12 coming back up river on a collision course straight for her, in taking avoiding action the K6 then rammed the K4, almost slicing her in half. Entangled with each other both submarines began to sink and it was only by going full astern that the K6 managed to break free and avoid being dragged to the bottom with the K4.

Seconds after the K4 turned over and sank. the K7 passed overhead and stopped to look for survivors.  Her deck party were stripped off and ready to enter the water to help their fellow sub­mariners but there were no survivors from the K4, all 59 crew being lost.

By this time the battleships and destroyers following behind HMS Fearless and her submarines arrived on the scene at 21 knots, ploughing through the cluster of damaged and confused ships, two of them missing the K3 by the thickness of her hull plating and washing the K7’s deck party off the casing, meaning they too had now to be rescued.

In a matter of seconds they passed over the spot where the K17 had gone down, chopping up or sucking under and drowning the men still swimming in the water. By the time they passed by only nine remained alive, one of whom died shortly after being picked up by the K7.

The K Class Submarine

The K Class submarines were monsters in their day, being twice as long and three times as heavy as other submarines of that era.

They had no fewer than seven power sources driving their twin propellers, a complement of 53 men, a maximum diving depth of 150 feet, 10 torpedo tubes, two of which were mounted in the funnel superstructure for surface use at night. They were also armed with two four inch guns and one three inch anti-aircraft gun.

Because of their technical complexity, a time consuming procedure had to be carried out before diving.  This included extinguishing the boiler furnaces for steam production, retracting the two funnels and covering their three feet diameter holes with water-tight plates closing four mushroom shaped air intake vents and about 30 other openings in the hull.

These submarines had to be trimmed with great care, the large, flat foredeck lacking buoyancy and producing a tendency to nose dive to the bottom.  Occasionally, sea water entered through the air intakes and down the funnels, extinguishing the boiler fires and causing explosions.  The water would short out electrical circuits and convert the boiler rooms into flooded saunas.

But it was none of these faults were responsible for the loss of over 100 lives and two submarines, and damage to three others as well as three ‘Skimmers*’ during the ‘Battle of May Island’.

K Class Submarine
K Class Submarine

The Aftermath

News of this disastrous episode was suppressed at the time but the subject has been relatively well covered in an assortment of books including The K Boats, by Don Everitt, which was published by George G. Harrap in 1963.

* The term ‘Skimmer’ is a submariner’s description of a surface ship, or officers/crew of same.

K4 and K 17 Memorial

There is a memorial to the lost submariners from the K4 and K17 in Anstruther, Fife, Scotland

K4 and K17 Memorial Stone

© Colin Murray (WMR-57976)

Memorial for the Battle of May Island