Page 18 - High Duty Alloys

Redditch Heritage High Duty Alloys

The HDA Sports and Social Club was founded in 1940 by employee Leonard Thorne, one
of those who moved from Slough, and a year (aged 20) later he actually passed out for
the RAF and went on to fly Hurricanes and Spitfires.

The administration and paperwork for the Redditch factory was, certainly at the start,
carried out by Slough. Three times per week key members of staff were transported
between the works by the company car (no motorways them of course, but then not much
traffic either). This usually took place three times a week and the various drivers vied with
each other to achieve the best time for the complete journey, until that is one went
through a wall at Shipston, after which the racing was stopped. Johnson’s Transport had
the contract for much of the heavy haulage required for raw materials and finished parts,
although some of these would also go by rail. I understand that HDA had its own railway
siding for the purpose.

Following enemy bomb damage to the forge at Slough, Redditch duly became responsible
for nearly all forged aero engine pistons produced in Britain during 1939-45, the final total
reaching over 10 million. It is not an exaggeration to say that pistons and other engine
parts made at Redditch for the Rolls-Royce Merlin engines which powered the Hurricane
and Spitfire made a major contribution to the winning of the Battle of Britain in 1940. The
development of aero engine aluminum alloys that could operate at higher temperatures
provided that extra bit of performance which helped the RAF fighters defeat the Luftwaffe.

A Merlin Piston

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