Friendly fire WWII

[Bruce Dennis]

At 20:00 on September 5th 1939, with the war against Germany two days old, Anson K8845 of 233 Squadron was patrolling out of Leuchars. The crew of two had been aloft for four hours, and were unaware that they had drifted considerably south of their estimated position. Below, they saw a submarine on the surface. The position was 56o 40.5’N, 01o 04’W.

HMS/M Seahorse was zigzagging at 11y knots, returning to her base at Dundee. Her captain, Lt DS Massey-Dawson RN was below deck as Seahorse moved along her predetermined route, 25 miles south of the air patrol line. Like several other of His Majesty’s submarines, they had been at sea when war was declared on the 3rd, patrolling preset areas. Twice earlier in the day they had dived after sighting patrolling aircraft, but had been left unmolested. At 20:07 another aircraft was sighted to the south, which turned toward the submarine. The Officer of the Watch couldn’t identify the twin-engined plane, and considered whether to fire recognition signals, which would take time, before leaving the bridge. He elected not to delay the dive by the few seconds this would take, and again the submarine dived.

Aboard the Anson, P/O Yorke went for the attack. As he watched his target begin to dive, he opened fire with his machine gun despite the extreme range. The two craft were in a race, with the Anson accelerating in a dive and the submarine forcing it’s way beneath the waves to safety. Seahorse won by a narrow margin. Yorke's two 100lb bombs hit the water near the sub as it disappeared. Both bombs bounced off the water and exploded underneath the Anson, peppering the aircraft with splinters. Yorke and Muir were satisfied that they had damaged a U-boat.

The crew of Seahorse heard the two explosions above them. As they attempted to level off at 75 feet, the aft hydroplanes jammed in the maximum angle. Yellow smoke candles were released in case the aircraft was friendly, but the submarine was now out of control. The bows broke the surface and those aboard believed more charges were dropped on them. The crew got partial control of the hydroplanes and the captain ordered the boat down. They hit the bottom at 220 ft, wrecking the A/S listening gear. Massey-Dawson stopped the Seahorse there and assessed the damage. He waited until 22:15, in the dark gap between sunset and moonrise, and surfaced. The boat resumed a zigzag course for Dundee.


Anson K8845 was leaking fuel. Yorke had set course back to Leuchars, but the wing tanks had sustained too much shrapnel damage from the bouncing bombs and he had to ditch at the River Eden Estuary, off Shelly Point. Both Yorke and Sgt DT Muir made it into their dinghy, were rescued unharmed and returned to Leuchars. They made their reports of sighting, attacking and damaging a U-boat and were celebrating in the mess when the word came through about the real identity of their ‘U-boat’. The Admiralty had confirmed that the Anson’s target had been HMS/M Seahorse, and that the submarine had received ‘…no appreciable damage…’, although it appears the Admiralty decided to keep quiet about the grounding.


Seahorse entered harbour at 04:00 next morning and carried out further inspections, then made course for Rosyth later the same day for repairs to her damaged listening gear and hydrophones.

On the 6th, Rear Admiral (Submarines) Watson reminded all Commanding Officers of the need to fire recognition signals when encountering aircraft thought to be friendly, and arranged a demonstration so the aircrews of 18 Group would know what they were looking for.

Seahorse started her next patrol on Saturday 16th September.