What had long been assumed to be a submarine wreck has been identified by German North Sea wreck-diving group Tidal Divers as a steamer called the Lotte Halm, which had its combustible cargo set alight by British bombers during WW2.
The group has now produced a detailed report on the ship they found last October, when members dived to investigate a mark almost 40km north of Nordeney on Germany’s North Sea coast.

Lying about 35m deep, it had been classified on nautical charts as a submarine by the German Federal Maritime & Hydrographic Agency (BSH), so the divers were surprised to find instead an iron steamship.
The stern section lay on its starboard side as far back as the boiler-room, while the rest of the vessel was inverted. The four-bladed port iron propeller was exposed and the starboard screw lay half-buried in silt.


The rudder blade was missing, though the hinges on the sternpost were visible, and the two triple-expansion steam engines lay about 9m from there, while the port boiler lay on its side 15m from the stern. The steel mast protruded from beneath the wreck amidships.
3D wreck model
The team, which is led by experienced wreck researcher Holger Buss, recorded the wreck in detail so that a photogrammetric 3D model could be produced. They then compared the results with records of the many ships that had gone missing in the area.

Based on the wreck’s 71m length, the design of its engine, which matched data held by Lloyds of London, and the memorable description of the sinking in war diaries, the team’s early guess that this could be the Lotte Halm was confirmed.
Although the ship had sunk during WW2 it had been built as an oil tanker for the German Navy early in WW1. She was later converted into a cargo ship but was given the Lotte Halm name only in 1927, after being acquired by a Cologne shipping company.

On 14 August, 1941, the ship was carrying timber from Sundsvall in Sweden to Papenburg in Germany. From Cuxhaven she had been ordered by the Kriegsmarine to follow a Norwegian cargo ship, the Marvel, and the two vessels had then hit a storm.
Three Bristol Blenheim light bombers from RAF Watton in Norfolk attacked them using incendiary bombs at 6.45pm, causing a series of structural explosions on the Lotte Halm and her timber cargo to catch fire, as well as the deaths of four of the crew.
The other seven, including Captain Josef Bielsky, got clear on a life-raft and were picked up by the Marvel and taken to the island of Borkum.
Still burning
Meanwhile the minehunter M572, patrol boat V1105 and tug Atlantic spent the night and the next day trying to extinguish the fire on the now-anchored Lotte Halm so that the ship could be towed to harbour.
The following evening they abandoned the struggle and attempts were made instead to scuttle the ship through shelling and depth charges. She had drifted away, still burning, though the next day her mast and a cargo boom were spotted.
Four minesweepers used sonar to search unsuccessfully for the wreckage over the next six days, after which it was decided that the Lotte Halm no longer posed any danger to navigation.
Tidal Divers found the ship using their RIB equipped with sidescan sonar out from Norddeich harbour. The team of nine dived using nitrox twin-sets in DIR configuration.
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