Restoring the Mk. I Spitfire, P9374

When the sands at Dunkirk finally gave up the remains of P9374; Tempus transit, vandals and salt had all done their best to ensure the task of rebuilding her was as big a challenge as is possible.  In fact, no Mk. I Spitfire had even been restored, and for those who think it is ‘just another Spitfire’, think again!

The Mk.I as a type was effectively the first production prototype; it was full of systems and equipment untried in RAF service, all of which had to be rediscovered today and for that reason, the very few surviving Mk. I Spitfires had been upgraded during their service life to reflect the inevitable shortcomings, and were of limited use to us as a true example of the Mk. I as originally conceived.  Our challenge was to re-construct P.9374 as near as possible to that day in 1940 when it force landed on the beach.

The task was thought initially to be hopeless, so a compromise specification was devised to incorporate what we did know, but otherwise to build loosely to the specification of the later Mk. Va Spitfire, which was visually almost identical, and for this, there was plenty of information available to help us. However, during the latter stages of the reconstruction, we came to realise that there was more information around than was first thought, albeit in the unlikely form of scraps from crashed Battle of Britain wrecks that had been excavated from deep down in the earth of South East England.

So – rather late in the day, we put together a team of specialists all of whom were called upon to contribute what knowledge they could.  We threw away that initial brief, and went for total authenticity – at least as far as is realistically possible. Gradually the information came in, and we found ourselves going backwards and undoing much work, especially in the all important cockpit areas which is very visible to the casual observer. However, this impetus created a new sense of challenge and enthusiasm which became infections as the in-house staff competed with the ‘experts’ to re-discover information.

Going back a few stages, our first task was to almost forensically examine every surviving scrap of metal from the wreck and assess whether we could use it again, or if it was just suitable for a pattern for remade parts. It surprised us how much we could use, especially from the cockpit and engine area, but those parts which could not be used gave away many secrets to help in the restoration work. Whether it was paint details, materials used or metal finishes, the clues were boundless.

The fuselage was outsourced to Airframe Assemblies on the Isle of White, who were given every re-usable scrap we could gather, together with airframe structure that would just be useful as patterns.  The propeller was too corroded to reuse, but nevertheless gave us a useful and complete pattern of what we wanted.  This, together with the hulk of the engine, was given to Retrotrack and Air Ltd, in Gloucestershire, together with a second Merlin.

This company was able to manufacture for us a totally authentic brand new De Havilland bracket-type propeller unit; this was a massive undertaking, and was just in time as the manufacturers subcontracted for the blade forgings were about to decommission the huge forge for producing the alloy blanks.  They also made the forged steel hub blanks, which were completed by Retro on CNC machines that were specially installed for the purpose.

The engine, despite 70-odd years immersed in the salt and sand, amazingly yielded some important and large castings for the engine, which were combined with a core Merlin III engine, sourced from overseas.

The wings were without doubt a big challenge and we decided to tackle these ourselves. This early wing had a number of features not found in the later Mk. V, but fortunately we had in the shop a pair of wings to refurbish from the RAF’s Battle of Britain Memorial Flight Mk. IIa, which was of an almost identical design to the Mk. I. We were able to examine many of the special features, though we also added the fabric covered ailerons, a quite visible feature on the Mk. I Spitfire, but not present on the Mk. IIa wing.  In addition to this, the wing had pneumatically operated landing lights, plenty of wooden structure, and a number of other features unique to the early Spitfires.

The undercarriage on the Mk. I was manually lowered and raised with an hydraulic hand pump.  In order to assist the loads, there was a complex system of springs and levers around the undercarriage legs, all of which had to be found or re-manufactured. So – the wing was pretty authentic now – we even found a set of .303” Vickers Browning machine guns, with their pneumatic operating equipment, the ammo boxes and chutes – and rarest of all, some 1940-dated belts of ammunition! All of these were deactivated of course, but were utterly authentic. Another item that had to be reproduced was the smooth-treaded Dunlop tyres.  We had discovered a very good original example, and this was sent to Dunlop to remanufacture, who were even able to reproduce the period script on the tyre walls.

With the new impetus, the enthusiasm in the shop grew as more and more changes were made to incorporate authentic and newly-discovered parts. Even the extraordinary ‘biscuit tin’ voltage regulator, very visible behind the seat was found and overhauled to working condition.  Stainless steel fastenings, which abounded on the early Spitfire, were remade from newly discovered drawings and the modern ones discarded. Due to the early batteries being less than adequate, the Spitfire was started with a remote battery held in a wheeled cart, called a ‘Trolley-Ac’.  One was discovered and restored, and to complete the external equipment, an excavated Battle of Britain wreck yielded the only known example of a cockpit canopy cover, which was copied, using a pre-war brown canvas army tent as the base material for complete authenticity! 

A modern radio was discretely hidden in a lift-up panel, and the pilot’s harness, although of modern material, were remade in the nearest colour to the original khaki brown. The search still continues for parts and we are especially seeking an original Dunlop control grip, probably the rarest of all surviving early Spitfire parts, as they were made of magnesium which easily corrodes.

There was no doubt that when the workforce watched the completed P9374 fly again, a real sense of pride and awe was felt by all of us.  We had put our very best into ensuring that this extraordinary and pioneering restoration of such an historic Battle of Britain Spitfire will now survive for future generations to enjoy, but also to remind us all of what a fine point in history had been tipped in our favour in 1940.