Good afternoon. The following is extracted from an article about the Volendam:

The Volendam, the lead ship in the middle column of the convoy, was torpedoed while it was several hundred miles off the coast of Malin Head, Northern Ireland. Two torpedoes stuck the ship on its starboard side in the area of Hold Number One. Only one of the torpedoes exploded. The attack had taken place in the early hours of 30 August 1940.
The first torpedo had caused a rupture 15 to 20 metres wide. The second torpedo was discovered minus its warhead near the transverse bulkhead in Hold Number 2. Some have theorised that the force of the blast from the first torpedo somehow dislodged and disabled the warhead on the second before it struck. Most commentators agree that had the second torpedo exploded, the Volendam would have sunk.
I am in contact with one survivor who was rescued with her sister, and put aboard the Valldemosa.

Phil