The conception, design and launch of ADO15 is well documented so we wont write an exhaustive article regurgitating old information but hope to write a brief résumé of the story .

XC9003 was the smallest of the trio of cars being conceived by Sir Alec Issigonis in the mid 50s; in March 1957 it became the basis of ADO 15. The brief from Sir Leonard Lord, as a consequence of the 1956 Suez crisis, was to design a proper small family car to “drive those bloody bubble car off the road”.

Thus the XC9003 proposal became the main focus of attention. Issigonis’s vision was for a box 10 feet by 4 feet by 4 feet of which 6’ 6” would be given over to passenger space, 1’ 6” to luggage leaving not more than 2’ in which to mount the engine. The only restriction on the design team was the insistance that an engine be used that was currently in production. This was to be the A-Series engine which measured 3’ 2” from the radiator to the back face of the gearbox. One of the key features of gaining maximum space was the adoption of 10 inch wheels to reduce the intrusion into the passenger space for the wheel arches. These were far smaller than the any wheel and tyre used at the time and required cooperation from Dunlop to develop a small enough tyre for the job.

The obvious way to save space length ways was to place the engine in a transverse position, but experimental Morris Minors had highlighted big problems accommodating the engine and gearbox in a track contempory with a small car. A two cylinder engine – made by literally cutting an A35 engine in half to create a 425cc twin – was rough and unrefined when used in an A35 test car.. So the now simple-sounding solution of placing the gearbox underneath the engine was born.

Thus the 948cc A-Series engine found its way into these early prototypes. By October 1957 the two Orange Box prototypes (so called because of their colour) had started testing with a West-East engine configuration, putting the carburettor at the front of the car and the plugs and distributor at the back by the bulk head. This was a mere 100 days after the wooden mock ups were completed themselves produced only 120 days after the original March 1957 start of the project. The cars wore Austin A35-type grills and 14inch wheels and usually ran at night in the Cotswolds (as the early testing was done by Cowley). This was done to fool the public into thinking they were a new version of the A35.

Sir Leonard Lord’s now famous July 1958 five minute run round the Longbridge site lead to an historic decision, with Sir Leonard stepping out of the car exclaiming “this is it, I want it in production within twelve months”, to which Issigonis replied, “Sir Leonard, this will cost many millions of pounds”. Sir Leonard rebutted, “Don’t you worry about that, I shall sign the cheques, you just get on with getting the thing to work”.

The initial testing meant that 4 important lessons were learnt:

1. The car was fantastically fast, perhaps undesirably so.
2. The carburettor iced up in cold weather.
3. The gearlever emerging through the fascia, as it did in the Orange Box cars, caused a lot of engine noise to pass into the car.
4. The drive was unacceptably harsh with very hard engine mounts, but the engine moved unacceptably with mounts soft enough to prevent this.

The two Orange box cars were submitted to 30,000 miles testing in 500 hours at the rough surfaced Chalgrove aerodrome. This lead to serious fatigue failures of the main body shell and was one of the main contributing factors in the subsequent adoption of front and rear subframes in order to distribute the stresses more evenly.

The rotation of the engine through 180 degrees was a result of the icing to the carburettor and presented more complications as there was a need to convert the transfer gears from 2 to 3 in order to change the directional rotation of the driveshaft’s. Otherwise there would have been 4 reverse gears and one forward! Unfortunately, this led to an increase in transition losses and noise levels.

However, it had become apparent that the 90mph speeds the prototypes were capable of were far in excess of those deemed necessary for the intended market. The engine was reduced in capacity by reducing the stroke from 73.72mm to 68.26mm thus creating a capacity of 848cc. Throughout Issigonis’ s professional life, it had become apparent that more stability was achieved with a nose heavy layout, but these early cars suffered with locking rear brakes to such an extent that Lockheed were asked to come up with a brake pressure limiting valve that gave even distribution of brake pressure throughout the system up to 40 psi, while cutting off the rear brakes leaving the remaining pressure in the front brakes if the pressure rose above this level. The moving of the battery into its now infamous position in the boot was also to help alleviate these problems.

The Mini we know and love today was now starting to come together, one of the last big design changes was the widening of the car by two inches, this combined with the reduction in engine capacity lead to an 18mph reduction in the top speed. The tyre width also increased from 4.80 inches to 5.20 inches. Cowley engineers found a novel way to test the CV joints at the village of Chalgrove by passing round a large tree in the centre of the village to see how many times they could go round it before knocking noise started. They used a variety of grease compounds until they discovered the best one.

It is recorded in the factory records that on 3rd of April 1959, foreman Albert Green hand built two Austin Minis at Longbridge 101 and 102, it is not known how long these took or when they were started but it marked the very first day the Mini as we know it entered production. With two more Austin’s being made on the 4th May, one on the 5th May, one on the 14th and a further 13 on the 15th these are the first 19 Longbridge Austin Se7ens made. Cowley production of the Morris Mini-Minor started with 101 (621 AOK) on 8th May 1959 with a further 9 cars all recorded as being made on that day.

However Peter Tothill has stated in person to the register that the first Morris Mini number 101 (621 AOK) was produced over the Easter weekend of 27th- 30th March 1959 at Cowley and sent up to Longbridge for evaluation for the Wednesday 1st April 1959. He distinctly remembers these dates as Cowley had a shut down before Easter and Longbridge after. Him and his team were ordered to work over the weekend and cancel their holiday’s, something that he still feels negative about to this day. The finished car had to be transported up to Longbridge to coincide with the re-opening of the Longbridge works on 1st of April 1959. The car was in turn put on internal display for evaluation and within 2 days on Friday 3rd of April 1959 Albert Green had used 101 as a reference to build Austin 101 and 102 (627 HUE). The further 9 Morris’s that are recorded as built on 8th May 1959 were slowly built up throughout April and early May, the 8th date being assigned to that batch as it was the first day the production records were started at Cowley and that’s how many cars had been built up until that date. All we need now is written proof.

The press launch of the new car was on 18th August 1959 at Chobham in Surrey, in order to give time to get the tests into print before the 26th August public launch. It was after this Chobham press launch that Laurence Pomeroy a journalist, author of The Mini Story and personal friend of Alec Issigonis wrote to George Harriman (managing director of BMC) suggesting that bona fide motoring journalists be given priority of delivery if ordering a Mini for personal use. This was after a barrage of requests enquiring when they could buy such a car! Harriman responded by offering 80 cars on a loan basis for 12 months with the option to purchase them at a fair price at the end of the time.

Both Cowley and Longbridge production ran almost in tandem throughout 1959 so that approximately 10700 of each were produced either as UK built cars or CKDs by 1st January 1960. There were many changes throughout 1959 with the biggest single change around the middle of October with the introduction of the smaller foot wells and modified radius arms.