T Type

T Type Description

The ‘T type’ was a relatively conventional mid-sized motor car. However it was a much more rugged design than the earlier Bamford and Martin cars. The only common part between the two was the radiator, which was the only useful item of stock left at the Bamford and Martin works, and too valuable to discard and re-design. A very few of the early cars also used the side-valve handbrake lever suitably modified to fit the brake cross shaft, probably for the same reason. With a relatively heavy nine feet six inch wheelbase channel section chassis, over slung at the rear (i.e. with the axle beneath the chassis) and with semi elliptic springs front and rear, it was fitted with a Bertelli designed worm and wheel rear axle. This was common technology for the period and it was connected by torque tube to the four speed crash gearbox, almost in the centre of the car. This was then connected by a ‘carden’ shaft to a short output shaft which ran through the pull-off type clutch bolted to the flywheel. There was a heavy ‘I’ section front axle beam with rod brakes and Perrot shafts at the front making it a recognizably conventional design, but of very high quality.

However, the Renwick designed steering arrangement was unusual, in that the steering box was mounted on the heavy cast aluminium bulkhead, with shafts and gears transmitting the movement through to the right hand side wheel, via a horizontal steering arm. It was complicated and expensive to produce and was quickly dropped in favour of a more conventional layout. The engine was the Renwick and Bertelli designed unit now of 1495 cc, with single carburettor and a wet sump. It produced about 50-55 bhp which compared well with the 40-45 bhp of the Bamford & Martin side-valve engine and was probably about as powerful the earlier B & M 16-valve racing engines.

Three cars were produced for the 1927 Olympia Motor Show; a saloon and a tourer, both on the long chassis (chassis numbers 1001 and 1002), and one shorter chassis sports three seater, the latter being not much more than a mockup. By the end of the event the saloon and the tourer had been sold, and a third car ordered. The short ‘Sports Model’ was dismantled and the parts returned to stock. A further twelve ‘T type’ tourers and saloons were built and sold in 1927 and 1928.

The ‘T type’ was a good quality car in its day, but the market for this size and type of car was crowded. The new Aston Martin, being relatively heavy for the 1½ litre engine, was somewhat underpowered and did not stand out amongst the many other similar motor cars available at the time. It was also more expensive than most at £575, a sum which would have bought a large family house at the time.

The last ‘T Type’, a saloon, built in 1928 was shown at the 1929 Motor Show, along with a two seater ‘Sports Model’, an ‘International 4 seater Sports’ and the ‘show’ polished chassis (chassis no. MS1).

The coachwork for the ‘T type’, both the open tourers and the saloons was built by A. C. Betelli’s brother Enrico (known as Harry). He had worked Bert Bertelli at Enfield Alldays and later had his own premises next door to The Aston Martin works at Feltham and traded as E. Bertelli Ltd.

All Harry’s work was beautifully made and very strong. Coachwork for the ‘T type was conventional four seat, four door touring style with attractive lines. Weight was kept down as far as possible by the use of aluminium for most body panels including the bonnet. However, both the front and rear wings, which were a pleasing shape the fronts running down into running boards, were steel for added strength. A luggage trunk, with the spare wheel attached was built onto the rear of the body tub.

The saloons were fairly typical for the period with four doors, the fronts being of the ‘suicide type’ with the hinges at the rear. They were very much the tourer with a fixed top, rather heavy and expensive to make compared to the open cars, but since the tourer was relatively low in profile so was the saloon. They were very well appointed and would have been comfortable if slightly slow and noisy to ride in for any length of time. At least one of the later cars had a split windscreen and a valance between the bottom of the doors and the running boards which cleaned up the lines of the car considerably.

Not many of either model were made, only three tourers are known to survive.

T Type Derivatives

Standard Four Door Four-seater Tourer

According to Aston Martin publicity material, the ‘T type’ was supplied from the factory as a ‘chassis, complete with wheels, tyres and all accessories’. The brochure then went on to describe how the factory had installed a ‘Coachwork Section’ and was thus able to produce ‘bodies of first class material and workmanship to customers own requirements’. In reality, the ‘Four Door Four –seater Open Car’ was the only open tourer that Aston Martin produced at this time and it is very unlikely that any were sold simply in chassis form. Only six ‘T type’ tourers were built. To quote the sales brochure; the emphasis was very much on the Aston Martin being a ‘Pleasure Car, rather than a “Family coach” type of vehicle’. Two examples are known to survive. Price £550

Standard Four Door Four-seater Saloon

The saloon version of the ‘T type’ was simply a tourer with roof. The mechanical specification was exactly the same, but the price reflected the extra work involved in making a closed body and the materials to upholster it. They were fitted with ventilators in the roof and were no doubt very well appointed inside. None survive. Price £675

T Type Specification

Chassis
12’ 6” in length, over slung at the rear. Steel channel section, tapering from the front to the firewall and then parallel to the rear. Five tubular cross members, two channel cross members, with heavily bracketed aluminium bulkhead section supporting the dashboard, firewall and steering box
Engine
Renwick and Bertelli designed 4 cylinder overhead camshaft 8 valve engine with wet sump
Bore 2.73”, stroke 3.9”, 1488 cc
Compression ratio: 6:1
Power: maximum approximately 55 bhp at 4250 rpm
Torque: approximately 50 lbft
Single carburetor, Zenith or SU
Magneto ignition
‘Autopulse’ fuel pump mounted on the rear of the chassis
Transmission
Aston-Martin designed 4 speed crash gearbox with straight cut gears, constant mesh main shaft and layshaft, dog clutch 4th speed and reverse. The internally ribbed aluminium box was mounted in the chassis on three ‘Silentbloc’ bushes. Standard ratios were 17.88:1, 11.49:1, 7.05:1 and 5.11:1. Connected to the Bertelli designed worm drive rear axle (gears by David Brown) via shaft fully enclosed by torque tube. Clutch is a ‘pull off’ type Borg and Beck
Steering
‘Marles’ box mounted on the bulkhead, shafts and horizontal drop arm to the steering arm on the off side brake back plate
Wheels and Tyres
‘Rudge Whitworth’, 52 mm x 21”, well base 60 spoke wheels with 2 ” wide rim, fitted with 29 x 4.40 tyres
Suspension
Semi-elliptic leaf springs all round, ‘Hartford’ friction dampers
Brakes
14”aluminium drums with shrunk in steel liners and 1?” wide cam operated shoes mounted on a single pivot actuated by rods.’ Perrot’ operated at the front. The handbrake worked directly on rear drums
Dimensions
Wheelbase: 9’ 6”
Track: 4’ 4”
Width: 5’ 5”
Track: 4’ 4”
Height: 4’ 6”
Weight: 16.5 cwt dry
Fuel tank capacity: 18 gallons
Performance
Approximately 60 mph
Price
Standard Four Door Four-seater Tourer: £595
Standard Four Door Four-seater Saloon: £675
Coachwork
Standard Four Door Four-seater Tourer: The coachwork for the ‘T type’ was built by A. C. Bertelli’s brother Enrico (known as Harry). He had worked with Bertelli at Enfield Alldays and later had his own premises next to the Aston Martin works at Feltham and traded as E. Bertelli Ltd. Coachwork was conventional four seat, four door touring style with pleasing lines. Wings were mounted on stays bracketed to the chassis. The front wings sloped back to running boards. A battery box was mounted in one front wing, and a tool box in the other. The windscreen opened from the base. All bright work was nickel and the spare wheel was mounted on the rear behind a luggage trunk. As with all Harry’s work it was beautifully made and had a well appointed interior upholstered in best quality hide
Standard Four Door Four-seater Saloon: The saloon version of the ‘T type’ was simply a tourer with roof. The mechanical specification was exactly the same, but the price reflected the extra work involved in making a closed body and the materials to upholster it. They were fitted with ventilators in the roof and were no doubt very well appointed inside. None survive
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