The Dorelian And The Mystery Explosion

Around 14:00 there was a mysterious large underwater explosion that was noticed by and affected many ships. Four ships from the convoy had just been hit within a 20 minute period and so it is hardly surprising that a ship when shaken by a large explosion assumed that they themselves were now victims.

Aurania

The escort Aurania reported the explosion, initially she thought that she had been torpedoed and then dropped two depth charges in case she had run over a submarine.

Cockaponset

The Captain of the Cockaponset, now in a lifeboat also reported the explosion, saying that it brought a quantity of dead fish to the surface but that no water was thrown up.

Norman Monach / Harpegus

The crew of the Norman Monarch having been rescued were now on board the Harpegus trying to catch the convoy which was still 5 miles ahead. The chief officer of the Norman Monarch reported the explosion as a dull thud rather like a depth charge but saw nothing.

Nicoya

The Commadore reported that the Nicoya stopped and blew off steam. Ships stopped when hit so they could launch their boats more easily. I assume the Nicoya realised she was not damaged before she launched her boats.

Dorelian

The Commodore also reported that the Dorelian (Alister's ship) had some men at work on its boat deck blown into the water. The Dorelian stopped and lowered its lifeboats. The Commodore reports that the Dorelian told him that they lowered the boats to rescue the men but he is puzzled as to why all the boats were lowered.

The explanation in the Dorelian's own log seems more likely. Times are I assume EAST.

11:10 Felt two heavy explosions under bottom. Vessel shaken and violently jarred. Assessment ship torpedoed, stopped engines and cleared boats.
11:13 Vessel apparently unharmed and engine room reported in order. Found that no 1 boat was lowered too far at one end and two men, W Jenkins, 2nd Steward and J. Pool, F and T (fireman and trimmer) thrown into water. Men picked up by 2nd officer in no 3 boat. No 2 boat also found to be unhooked at one end.
11:39 All men on board. Boats abandoned for dispatch. Vessel proceeded full speed.

The Dorelian was now without life boats in a situation where she may well need them.

The Cause

The Director of Antisubmarine Warfare was interested in this event. (ADM 199/1708 A Report From Regent Panther 7th June 1941).

They postulate three causes.

1. Darlington Court blew up
• No because cargo 8,000 tons of wheat
2. British Security blew up.
• No because it was still on fire on the surface
3. A U-boat blew up
• No because the explosion was too big. (This seems an unsound assumption but regardless we now know there was no u-boat casualty at this time.)
4. An earthquake
• This is not dismissed in the report but also not accepted. As dead fish were reported following the explosion I think we can dismiss this on the assumption that the water was deep.

I have not found a subsequent report making any conclusion. However it seems likely to me that the explosion was caused by the Cockaponset that had just sunk containing burning paper, 320 tons of TNT and 340 tons of cannon powder. While the Cockaponset was not considered in the original report its captain B Green has made extensive notes on his questionnaire reporting to the Shipping Casualties section of the Trade Division. While he cannot see how the explosion occurred it seems to me to be the only possibility.