Recovered from the bottom of the sea

These three heavily corroded aircraft engines were fished up by Texel fishing boats on the North Sea. All three of them are from planes that crashed at sea in World War II. The one in the middle is a 14 cylinder radial engine labeled Pratt & Whitney, manufactured in the USA. The Liberator and the Halifax were equipped with such an engine in the war. The other two engines are labeled Bristol Hercules and were manufactured in Britain. The heavy and medium heavy bombers of the RAF were equipped with this type of engine. It is different from other engines. It does not have any intake and outlet valves but a working cylinder with ports in the 2-stroke principle. 

Fig. 1 - Museum Kaap Skil, Oude Schild, Texel
Texel is n island in the North Sea, in the north of The Netherlands.

The microscopic images show serious corrosion to the aluminum alloy of a certain part of the engine, caused by the aggressive seawater. The corrosion product shows fluorescence when exposed to UV light. These are compounds that are formed by a chemical reaction between the metals present in the alloy and the seawater.

Fig. 2 - Corroded aluminum alloy aircraft engine part under an SMZ-171 microscope and a Moticam 1080 BMH stack  

Fig. 3 - Corroded aluminum alloy aircraft engine part under a BA410E microscope PlanFluar 10 X (DAPI filter) and a Moticam 10 stack.  

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