The Spitfire MkI.....

A production order for 310 aircraft was placed on 3rd June 1936, before any report was issued from A & AEE.
The same day a contract for 600 Hurricanes from Hawkers was also signed

The order for Spitfires comprising.......
Mk1 K9787 - K9999 & L1000 - L1096

 

Technical Description

First 74 to K9960 fitted with Merlin II engines and first 77 to K9963 fitted with Watts two bladed propellers. All later retrofitted with De-Havilland constant speed three bladed propellers. Aircraft after K9960 fitted with Merlin III engines.

The Spitfire Mk1b...

Also within this period of development was the Spitfire Mk1b this was the first machine to be fitted with cannon. Two Hispano-Suiza had been fitted to a Mark 1 for evaluation to counter the harder hitting German Armament. Big problems were experienced with these guns jamming due to the drop in temperature at higher altitudes. A system of gun heating was developed  by the 'works' to cure this problem. There was always a heavy responsibility on the armourers to ensure the gun magazines were loaded correctly  to avoid the dreaded 'gun' jam during a dogfight.
92 Squadron  based at Manston were one of the first squadrons to be so equipped, they were involved in much of the front line testing of these weapons
The addition of cannon did not meet with universal approval. Certain C.O.s including the infamous Douglas Bader, were of the opinion that the eight Browning machine guns had sufficient punch, as long as the pilot got close enough to the enemy aircraft..

Project N.17.....

A project which is worthy of mention is Spitfire project N.17. This machine was built to try to capture the World Landplane Speed Record.
During the latter part of 1937 Rolls Royce  were developing a special 'sprint' or 'Schneiderised' version of the Merlin to produce 2000 hp. Two std Merlin II engines were taken for bench trials and using 3200 rpm the supercharger boost was wound up to
28 1/2 lbs, more than 2000 hp was achieved. At such high boost  special fuel was used a 20-60-20 mix of Californian Gasoline, 'Nineties' Benzol and Methanol with Tetra-ethyl-lead added at 4 cc per Gallon. The 48th production Spitfire K9843 was modified to take this Merlin engine, the wings were shortened, the main cooling radiator was increased in size, the canopy and tail skid were changed for a more streamlined version and the aircraft was given 16 coats of high gloss paint. The propeller was a wooden four blade fixed pitch albeit, greatly increased pitch angle. The outcome of all this was a maximum level speed of 408 mph, not enough to take the record. Further modifications were tried in order to reduce the drag including a total loss cooling system. However time and money ran out and more pressing duties were looming on the horizon. The aircraft was refitted with a production Merlin XII engine and given to the PRU as a hack, well it was already painted blue. It was never fitted with cameras, never flew operationally and survived the war.

So why bother to mention it?

The importance of this project at the time, was to convince Joe Smith who had eventually taken over as Supermarines Chief Designer  following the death of R.J. Mitchell in June 1937, and his colleagues, of the potential, of both the Merlin engine, a reliable 2000 plus hp, and the ability of the Spitfire airframe to handle such power. The only modification to the engine was to increase the boost pressure.
The Spitfire and the Merlin engine were proved to be worthy contenders for further development.
At times it became necessary for Joe Smith to defend the Spitfire, although much liked by the squadron pilots from the outset, the machine was never much liked by the Air Council or the Air Ministry,  largely because of the production difficulties causing delays during 1937/38. The Spitfire construction of all metal and stressed skin panels caused great problems to start with. The wings in particular were very troublesome and there were often cases when completed fuselages would be hanging around, waiting for the wings to be delivered. The Supermarine company had never had an order for more than 10 of any other aircraft and were certainly not equipped at this time for any form of mass production.
There was a serious proposal to turn Supermarine production over to Beaufighters. It is a sobering thought that this talk of phasing out the Spitfire was going on only 14 months before 'The Battle of Britain'.

Joe Smith knew that if this happened it would be the end of the Spitfire, so he pressed on with the next two stages of Development, the first a minor one and the second more substantial.

Things were changing quickly, one of the most significant, as far as Spitfire production was concerned, was the acquisition of the Castle Bromwich factory near Birmingham