How Aston Martins Are Made
A Visit to the Newport Paynell Factory
The history of Aston Martin has been long and illustrious, and looks like being just as interesting in the future as it was in the past. I have been enthusiastic about this famous British sports car for very many years. I remember calling on Mrs Lionel Martin, after her husband’s death, to talk about the days of the Bamford and Martin Astons. I recall how impressed I was about the then-new Bertelli Aston Martin with its complex specification, which embraced o.h. camshaft operating a row of leaning valves, dry-sump lubrication, a combination of thermo-syphon and pump cooling, worm final drive, etc.—I read the catalogue in a Southern Electric train going back to London from Feltham, because I hadn’t even an Austin 7 in those days, which shows how long ago this was!
I subsequently tried many Aston Martins and Motor Sport road tested a DB2 in 1951, under adverse winter conditions. But after that our relationship with Aston Martin Lagonda Ltd. deteriorated. However, these very fast British status symbols, with their racing pedigree and twin-cam six-cylinder engines going back almost as far as Jaguar’s famous power unit, are difficult to disregard, so, under the new Sales Promotion-ship of Brian Perks we went down to Newport Pagnell last month, to look round the factory and lunch with Mr. Steve Heggie, Deputy Managing Director, Mr. Dudley Gershon, Director of Engineering, and Mr. Roy M. Bamford, Director of Marketing.
Early in 1967 the prices of the David Brown Aston Martins were slashed by £1,000, to combat crippling increases in purchase-tax. As dramatic as Morris’ historic price cuts in the early twenties, this saved the Company, and today production is on a very satisfactory basis. The £4,595 DB6 is made at the rate of about seven a week, the drophead Volante at two per week, and some ten DBS Aston Martins are made a week, a total of over 80 hand-built quality motor-cars a month. Of these, 50% have standard engines and automatic transmission, 30% the Vantage engine, the remaining 20% being turned out with the manual gearbox and/or Stromberg carburation.
Today Aston Martins are made in Newport Pagnell, close to the M1, which is convenient for tests—at up to 70 mph.!
They occupy premises on both sides of the Tickford Road, the main factory having been built in 1964, but the office block and one bay being the old Tickford bodyworks, where a few N.P. cars were assembled. Across the road are the research establishment, engine test shop, restaurant, and the 100-car Service Department, the latter unique, inasmuch as it deals directly with retail business, in competition with dealers, and repairs and services all manner of Aston Martin and Lagonda cars, back to DB2/4s and W.O. Bentley models.
The essence of the Newport Pagnell factory is “ordered confusion”, or so it looks to a visitor. Workers, permitted to smoke, cluster around cars in various stages of completion, shaping body panels by hand to the clatter of hammers.
DB6 and DRS models are built on the same, two-lane, hand-moved line, later becoming a single track, which is at floor level, except when the body shells rise on to ramps, over open pits, for the suspension units to be fitted. The DBS is more complex than the DB6 body shell, with a tubular top structure, and it requires more pressings and swaging, with welded instead of riveted joints. The shell of a DBS locates such items as lamps, brake units, radiator grille (made from strip brass), bonnet locks, etc., and is shorter and much wider at the front than a DB6 shell. The mild steel pressings for the DB6’s superstructure are 18 and 20 g., 16 g for the base shell. The bodies of the DBS are panelled in light-alloy sheets, supplied stretch-pressed by Boulton Paul Aviation Ltd., DB6 and Volante alloy panelling is made in the factory’s own press shop, the biggest machine being a Bliss press. The DB6, primarily aimed at the Home Market, has a single pressing for its doors, the DBS utilises two pressings.
The factory has some 200 to 250 bodies going through, the production process for a DBS being as follows: The steel platform chassis provides the main torsional and beam stiffness and also acts as a base for the body superstructure. The chassis with its integral bulkhead is fabricated at the David Brown plant at Huddersfield and was developed over the past ten years from the original DB4 structure.
The bulkhead forms a member of enormous strength from which the forward extension beams protrude carrying the engine and front suspension loads and providing a progressively collapsible area to absorb impact energy in the event of an accident, leaving the passenger compartment undisturbed.
Robust, heavy-gauge side members are employed, on to which the body sills are attached providing additional protection from side impact. The body superstructure is jig spot-welded to form the two side sub-assemblies incorporating the door sills, “A” posts carrying the door pillars, windshield pillars and roof cant rails. The front subassembly is similarly constructed and carries the front aluminium body section, water and oil radiators, bonnet and headlamps. This assembly also forms the front wheel arches obviating the need for internal panelling. The completed chassis is then inspected using aperture check gauges prior to receiving rust inhibitor and moving into the panel shop. Body panels are built up into the front, roof and rear sections from rough pressings which are then welded and beaten by hand to produce each section. The completed panels are then offered to the chassis. The front section is secured to the superstructure by rivets and epoxy resin adhesive and swaged round the door pillars whilst the roof and rear sections are welded into a complete unit on the car, being secured by swaging and riveting in position.
During this stage the apertures are again checked as the panels are fitted on to the chassis, the final panel shop operation being the complete inspection of the chassis body unit and the etching of the panelling to take the paint. The body then passes into the paint area, where it is washed down in acid, rinsed, the engine compartment treated with fire-proof compound and the underbody sealed before the first coat of etched primer is baked for 30 minutes at 300°F. The shell then receives eight coats of synthetic resin primer, each coat being flashed off for half an hour and baked for a further 30 minutes at 300°F. The shell undergoes inspection and guide coating half-way through this process. Passing on to the spray booths the car receives two coats of cellulose sealer before the application of the 12 coats of the final colour, each double-header coat being flashed off for 30 minutes and baked at 160°F for a similar period.
The paint process is exceedingly thorough, using self-contained hand-guns, not pressurised. Depending on the time taken to complete the spray job, a total of some nine gallons of I.C.I. paint per car is used. It is interesting that Aston Martin owners continue to ask for metallic finishes. In 1967 the most popular of 11 standard colours was Silver Birch, but in 1968 Dubonnet Rosso took precedence, while this year the favourite is Aquamarine.
Aston Martin make their own seat frames, do all their own trim and upholstering, using approximately 270 to 285 sq. ft. of Bridge of Weir hide (favoured because the dye goes all through the material) per car. Five standard upholstery colours are listed, but personal requirements can be met without extra charge.
The cars move along on sets of slave wire-wheels in the shops, are given other wheels for road-testing, and the final set, Avon-shod, only when passed out as ready for delivery.
Salisbury supply the differential unit for the DBS’ De Dion back axle, but the factory machines hubs, outer drive-shafts and completes the De Dion tubes. Power steering is ZF, as are the 5-speed manual gearboxes. Borg Warner supply the automatic transmissions.
There is a big machine shop where rough components are finished, and every stressed part is crack-tested. Cylinder blocks are bored and machined on a £30,000 automated, computerised Dixie and cylinder heads completed in one process, on a Hydroptic machine. The Laystall crankshafts are checked for balance before and after the flywheels are fitted and pistons and con.-rods are used in matched sets of six, carefully weighed on Avery balance, with a plus or minus tolerance of 1/16 oz., although usually the weight of piston against rod, or vice versa, means that the balance is equal throughout. The main bearings are bore finished to a 6/10,000 in., checked on a Solex air gauge, with shells tightened to 55 lb., the tolerance permitted being between 0.00125 and 0.0005. Cylinder bores are accurate to 0.0004 in. The linkage for the Triple Webers for the Vantage engines is made in the factory. Cylinder blocks, with liners pressed in, are checked for porosity under air and oil pressure, small seep-holes in the block-showing whether leakage is from top or bottom of a liner, in the rare event of any porosity.
Each engine is built up by hand by one man, who starts by selecting his cylinder block from the test bath; five men work on engine building. It takes 11 hours, to make a DB6 engine, 13 hours for a DBS. Aston Martin do not have a foundry, British Aluminium supplying most of their castings; cylinder liners are Hepworth and Grandage. Complete engines go across the road to be run on one of four H. and F. water brakes, first on gas, at 2,000 r.p.m., for four hours, then for 30 to 60 minutes on petrol, when h.p. and torque readings are taken at 5,000 to 5,500 r.p.m.
Each finished car goes out for a 75- to 100-mile road-test, over three different routes, two test drivers being employed, and then returns for final inspection and checking.
The time taken to make each Aston Martin can be as much as nine weeks. It represents 1,200 man-hours of painstaking hand construction. The factory employs 800 people, of whom about 450 are engaged in car production. To facilitate this work 25 Inspectors wear green coats, the four Foreman Inspectors blue collars on their white coats, the eight Production Foremen red collars and charge hands green collars on white coats. As assembly proceeds individual data sheets for each car are brought up to date. The Volante hoods are made by Aston Martin, their electro/hydraulic hood operation, introduced in 1966, being the first of its kind in Europe, now adopted by Rolls-Royce Ltd. This model has twin fuel tanks, to provide space for the furled hood.
It is evident, after a visit to the Newport Pagnell works of Aston Martin Lagonda Ltd. that Britain does not lag behind in the building of craftsman-constructed quality GT cars. We look forward to road-testing a modern Aston Martin in due time and meanwhile commend the care with which these David Brown cars are made, in the Lionel Martin/Bertelli tradition, Jensen and Rolls-Royce not being the only companies to build their own bodies, as I was led into stating, some time ago!—W. B.