1928 Latham expedition
Wreckage – Fuel tank, found 13 October 1928
On 13 October 1928, the crew of the fishing boat Leif found a fuel tank on Haltenbanken, west of Namsos.
The Leif‘s captain, Leonard Olsen, spoke to the newspapers about the discovery: “It appeared to be a blue-grey aluminium tank in the shape of a bathtub.” 📜 After the fuel tank was landed in Vasøya in Vallersund, it was transported to Trondheim and placed in the customs sheds.The tank was then transported by train to Oslo, where it was examined by pilots Hjalmar Riiser-Larsen and Finn Lützow-Holm and others before being finally sent to the French Ministry of the Navy in Paris.

The fuel tank was measured and described as:
Length: 120.0 cm
Width: 56 cm
Height: 80 cm
It was made of metal and painted a grey-blue colour.
It was concluded that this was Latham 47.02‘s front internal fuel tank, the tank located closest to a hatch behind the cockpit through which all the fuel tanks could be removed. The hatch was fastened with bolts, and all the tanks were fastened with metal straps along strong stays on the aircraft. The tank was estimated to contain about 30 litres of fuel when it was found, and despite some dents, was intact.

On the tank were some pencilled inscriptions, which were interpreted first as a message from the crew but then determined to be records of fuel consumption and pressure made by the mechanic on board before departure.
The investigations also revealed that the drain cock had been torn off, but this was explained to have happened on the deck of the Leif when the tank came loose in a rough sea. Further confirmation of the tank’s identity was found on the filler pipe, which bore a small brass plate stamped: “Essence. Contenance 600 litres, Hydravion Latham.”
Another key observation was made in the filler nozzle, which had also come loose on board the Leif. Into a copper vent pipe soldered to the lid of the nozzle had been placed a wooden plug that sealed the pipe. This plug consisted of light wood and bore marks from a knife. By cutting through the copper pipe, the wooden plug could be retrieved undamaged. Subsequent investigations and enquiries established that the wooden plug had not been inserted into the vent pipe in Caudebec-en-Caux before departure. Along with the wooden plug, a gasket around the filler nozzle had also clearly been worked with a knife.

The marine investigation in Trondheim and further investigations in France found that if the tank were placed in the sea, it would turn so that the side with the filler nozzle was lowest. The wooden plug would then prevent seawater from penetrating into the tank. This generated several theories in which the tank had been dismantled by the crew. French aviation experts and representatives from the Latham factory thought it impossible that the fuel tank had torn loose from the fastenings in an accident, and that the aircraft had not therefore crashed and sunk, at least not immediately. The wooden plug and the worked gasket were proof that the crew must have had both time to remove this tank and a reason to modify it. An obvious possible explanation was that one of the Latham’s floats had been destroyed, and that to restore the aircraft’s stability the crew had used the fuel tank as a makeshift float. Albert de Cuverville, the French co-pilot and navigator on Latham 47.02, had done something similar on a previous flight.
This tank was sent to France and is probably the one currently owned by the Musée de l’air et de l’espace (French Aviation and Space Museum). In that case, it is today exhibited together with the float at Le musée de l’hydraviation de Biscarrosse (Aviation Museum in Biscarrosse, France), while the tank found in 1929 is exhibited at the Polar Museum in Tromsø.
Sources:
Kristensen, Monica: Amundsens siste reise
Hovdenak, Gunnar: Roald Amundsens siste ferd📜
Latham-ferden: Roald Amundsens endelikt. Utgitt av Vågemot miniforlag, 2014.📜