Atom

Sutherland Aston Martin, 1936-1940

The Atom

Forward thinking, Gordon Sutherland and Claude Hill had recognized in 1938, that future competitive market needs dictated a radically different type of saloon to maintain the fortunes of the company. They produced a design with sports car performance, and exceptional road holding, combined with significant ride comfort and yet economical. The new car was strong but as light in weight as possible. The radical body frame, a further development of the ‘Donald Duck’ experiments in 1938, was a space-frame onto which different panel designs could easily be attached without fundamental design changes.

The new car was first road taxed with the Department of Transport for road use on the 14th July 1940. The name "Atom" was chosen as it implied something small but very powerful and the name was duly registered with the Society of Motor Manufacturers and Traders (SMMT). That the car was built at all is amazing throughout the nation, railings, pots and pans and all sorts of metal articles were being melted down for the Second World War effort and British troops had just been evacuated from Dunkirk. The lack of materials indeed inhibited the design, which would otherwise have had a longer wheelbase at 9ft 3"and lower floor, scuttle and side aspect. Interestingly, it was the first fully functional concept car in Europe and probably the second in the world. ‘Atom’, brought together in one car, a wide range of new technologies.

The existence of the "Atom" was publically revealed at the Rivers-Fletcher enthusiasts meeting at Chessington in July 1940. Later, in the Autocar in October 1940, H.S.Linfield described it as "the post war Aston" and was impressed by how many miles in an hour, in comfort, he could travel. In Motor Sport in June 1942 Cecil Clutton reported that on the road "this is a machine which convinces you within the first half mile that it is a winner. I have never driven a car which I could handle with greater confidence in the wet". A month later, Laurence Pomeroy stated, ‘in this car we can see the new order of motoring before our eyes. A peep into the future’. All these road test were carried out with a relatively standard 15/98 engine which could power the ‘Atom’ on low grade wartime petrol to some 95 mph, a major achievement for an undeveloped two litre car. Carefully documented developments continued, albeit inhibited by petrol shortages during wartime, even for those engaged in war work. Nevertheless some 100,000 miles were logged by Gordon Sutherland, much of which was achieved going to and from the Feltham factory, often via ‘the pretty way’!

The ‘Atom’ incorporated innovative features that were a complete departure from normal practice. The initial experiments in 1938 on ‘Donald Duck’ proved that with steel tubing fixed to a traditional chassis with panel work fitted to it, produced a particularly strong structure. This was an essential step towards the hoped for introduction of independent front suspension in a future Aston Martin. Coincidently, the newly patented Gordon Armstrong front suspension system of trailing arms, coil springs and split track rods, was available for the first time, and with slight modification by Claude Hill, it was used on the new car. This type of independent suspension demanded a torsionally rigid chassis to prevent front scuttle and suspension mountings from twisting under load, not a characteristic of the then traditional ladder frame chassis. Fortunately Claude Hill had now refined and patented (with Aston Martin) the revolutionary lightweight framework of square welded section channels reinforced by cross braces and clad with light gauge aluminium panels.

Using different tube sizes to reflect various stress levels, the body and chassis were effectively one-piece, allowing for the first time a variety of body shapes to be created on the same homologated structure. A double bulkhead was fitted with asbestos insulation. Once all the lightweight cladding had been bolted or self tapped (Aston Martin used these fasteners for the first time on ‘Atom’) together, a very rigid but light body was produced. The total weight of the car was 24 cwt.

Conventional semi elliptical springs were fitted to the rear with hydraulic lever arm Armstrong shock absorbers. Lockheed hydraulic brakes were fitted to front and rear. Contemporary aircraft technology was reflected in the streamlining of the car and its window, seat, and fastener design.

The transmission was novel. The hypoid differential from Dana in the USA (the ‘Salisbury’ rear axle) was reputedly the first to be used before GKN took on the UK license. A French Cotal electromagnetic semi automatic gearbox was used. This gearbox was essentially two gearboxes in one. One selected forward, neutral and reverse, the other selected gears by electromagnetic activation. The same ratios could be selected in reverse, and the car was therefore capable of its maximum speed, also in reverse. Although a conventional clutch was fitted, gear changes were normally made simply by flicking the gear selector switch.

Limited development of the single overhead cam 2 litre ‘15/98’ engine had continued during the war with experiments using Zenith carburation, and different ‘extractor’ exhaust systems. However, by 1944 Claude Hill had finished designing the new 1970 cc, 90 bhp, pushrod engine which was immediately installed in the Atom. The engine was patented in March 1945 and described in Autocar (October 25th 1946) and Motor (November 6th 1946).

It was not until July 1945, at the first Cockfosters rally that Sutherland showed the 2litre pushrod engine (later to be called the DB1 engine) that had been developed with the many patented features. It was in this format and with the car being capable of a speed in excess of 100 mph, that David Brown test drove the car in 1946. There is little doubt that his positive experience with the ‘Atom’ went some way towards his being persuaded sufficiently to buy the Company. It is a widely held belief that Aston Martin would not have survived post-war without the ‘Atom’. Indeed the front suspension, Salisbury back axle and body construction method are clearly seen in the subsequent DB1, 2 and DB2/4 series.

After the factory had been sold to David Brown, Gordon Sutherland retained ‘Atom’ for his personal use, until it was sold into other private hands in 1949. The car was later owned by Mr Bob Gathercole (Godson of WO Bentley) who used to amaze onlookers at Sandhurst by driving at high speed in reverse whilst changing gear. Later in 1965 the car passed into the ownership of ex Aston racing driver Nigel Mann and remained mainly in France at the Museums of Chatellerault and the Le Mans circuit until 1986, when the car returned to the UK. It underwent a documented conservation programme instigated by Dr. Tom Rollason, reappearing in 1996 at a special reunion of the car with Mr. and Mrs. Gordon Sutherland at the factory. The car remains in private ownership.

Specification

Chassis. The construction method was patented by Aston Martin and Claude Hill jointly, Patent Spec. No. 527,067 dated 30/03/1939. A very stiff box frame structure was constructed using 2½" x 1¼" 13 gauge and 1¼"x 1¼" 18 gauge square section steel tubing. This was then paneled with aluminium fixed to the tubing with self tapping screws and nuts and bolts with ‘Nylock’ nuts. This was the first time such fixing methods had been used.

Engine. Initially a standard overhead cam ‘15/98’ 2 litre engine was fitted (see ‘15/98’ specification). Some experimentation was done with carburetion (Zenith) and exhaust manifolding during this period. From 1944 the Claude Hill wet sump pushrod 2 litre engine was used.
Bore: 78mm, stroke: 102mm, 1970 cc.
Compression ratio; 7.75:1
Power: 90 bhp
Torque: approximately 115 lbft.
Twin side draught 1½" SU carburetor with thermo choke.
Ignition by Lucas sports coil and breaker.
Twin SU fuel pumps.
‘Auto-Klean Full Flow’ oil filter.

Transmission. ‘Cotal’ electromagnetic 4 speed semi-automatic gearbox. A single plate Roper and Reach clutch was fitted. Gear changing was normally accomplished by electric switch. ‘Salisbury’ hypoid bevel rear axle. Ratios: 15:1, 10:1, 6.68:1, 4.55:1. A number of final drive ratios were tried, including 4.09:1 and 5:1.

Steering. Marles worm and roller. The drag link connects with a bell crank lever centrally mounted on the front cross member. From this twin track rods run backwards at an angle giving perfect steering geometry. Steering circle: 35 feet.

Wheels and tyres. Rudge Whitworth 52 mm 17" well base wires with 60 spokes and 2 ¾" rims fitted with 5.50 tyres.

Suspension. Independent at the front, by modified Gordon Armstrong patented trailing link and coil. Semi-eliptical leaf springs at the rear. Gordon Armstrong hydraulic lever arm shock-absorbers fitted to front and rear.

Brakes. Lockheed hydraulic on 12" diameter drums. The handbrake works on the rear brakes only.

Dimensions.
Wheelbase: 8’ 6"
Track: 4’ 2"
Length:
Height:
Weight: 24 cwt.
Fuel tank capacity: 17 gallons.