Three-way
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Iding in the
NEW AUSTIN , 25-cwt. VAN
PRELIMINARY details of a prototype Austin 25-cwt. van, together with an exclusive illustration of the complete vehicle, were published in our issue dated July 5, 1946. Details of the design have since been made final, and we, are now able to publish a full description of this new addition to the Austin range,
The primary object of this new van is to provide a vehicle particularly well suited to local delivery work. especially in congested areas. To that end, special attention has been paid to manoeuvrability, visibility, large load capacity in relation to chassis weight, and ease of loading and unloading.
The attention paid to the last-named feature is reflected in the name adopted for this model—the 25-cwt Three-way van—the term Three-way signifying the provision of three separate means for access to the load-carrying portion of the body. Wide side doors are provided, just aft of the cab, in addition to the usual rear doors, so that loads can be handled with equal ease, no matter how the van be parked.
Chassis features include a short wheelbase in relation to overall length, a straightforward frame design giving unusually good ground clearance, a forward-mounted four-cylindered o.h.v. engine of 2,199 c.c., conventional transmission, semi-elliptic springs fore and aft, and Girling hydraulic brakes of the two-leading-shoe type.
Main overall dimensions are: Length, 15 ft. 6 ins.; width, 6 ft 5 ins.; height, 8 ft. 1 i ins The wheelbase, on the other hand, is only 7 ft. 9 iris., giving an overhang at each end of the vehicle of 3 ft. 10-i ins. This arrangement has been adopted in order to provide a minimum turning circle (less than 40 ft. is required, even allowing for the overhang) and good ground clearance. Axle clearance is 94 ins, at front and rear, and the lowest mid-chassis point is 15 ins, from ground level. The track is 5 ft. 1 in.
Prices are £535 for the complete van finished in primer, £409 for the chassis and cab, and £340 for the chassis only. .
The frame consists of two deep, channel-section side members, running almost straight and level from front to rear, braced by four channel-section cross-members. Of these, the front member, which is secured by six bolts on each side, carries the front mounting of the engine and the radiator, and is detachable to facilitate removal of the complete power unit. The engine is also supported by the second cross-member, through which a circular casting at the rear of the gearbox passes; this circular casting, in which the speedorrieter drive is situated, is surrounded by a rubber sleeve which fits into, and is compressed by a housing bolted to the crossmember. This forms the rear flexible mounting of the engine and gearbox unit.
The radiator grille is readily detachable to allow the engine to be withdrawn. Neither the radiator nor the front flexible engine mountings need to be' disturbed. The unit can be withdrawn with a minimum of disconnection and dismantling, and with no subsequent difficulty ip obtaining correct alignment.
It should, however, be emphasized that all engine auxiliaries normally requiring attention are accessible when the cowling within the driver's cab is either partially or wholly removed, and it is quite practicable to remove the head and decarbonize the engine without withdrawing the unit from the chassis, At the front the engine is mounted on bonded-rubber blocks sandwiched between brackets bolted, respectively, to a stout bearer plate attached to the front Of the crankcase and to the detachable cross-member. The rubber bloCks, are at an angle of, approximately 45 degrees to the vertical, with their upper end farther apart than their bases; as a result, the rubber is in cornpression, so 'far as the weight of the engine is concerned, and 'in shear in respect of the tendency of the unit to rock under vibration.
In practice, this arrangement has proved particularly effective in damping out vibration, the arrangement being helped, no doubt, by the inherent smoothness of the power unit, which is basically similar to the engine used in the Austin Sixteen car.
This unit has a bore of 79.4 mm. (3i ins.) and a stroke of 111.1 mm. (4b ins.), giving a total swept volume of
2,199 c.c. (134.1 cubic ins.). The R.A.C. rating is 15.63 h.p., and the unit gives 65 b.h.p. at 3,700 r.p.m., with a maximum torque of 115 lb.-ft. at 1,900 r.p.m. The compression ratio is 6.85 to 1.
The four cylinders are cast integrally with the crankcase and the cylinder head is detachable complete with the push-rod-operated valve gear.. Three thin-wall bearings support the forged-steel camshaft, which is driven by a Diaplex roller chain with a synthetic-rubber tensioner ring to provide quiet operation.
No-loss Radiator The cooling water is circulated by a pump and fan, and a thermostat controls the temperature. A noteworthy point about the radiator is The provision of a simple arrangement in the header tank to prevent loss of cooling water and, anti-freeze, either by splash or expansion. As an accompanying illustration shows, the filler cap is of special design, arranged so that water cannot be added above a level which will prevent normal expansion. In addition, the overflow pipe ts, taken from a small dome in the header tank and leads to a small chamber formed around the upper portion of the extended filler cap, above the level of the actual water seal.
Should water, be discharged through the overflow pipe; it passes into this small chamber and, apart from any .quantity which may actually escape around the upper portion. of the cap, is drawn hack again into the header tank by suction when the radiator cools The total capacity of the cooling system is 21 pints A counter-balanced forged-steel crankshaft is employed, supported on Three detachable thin-wall bearings. This type of bearing is used for the big-ends of the connecting rods, which are also of forged steel The pistons, of aluminium alloy with an anodized surface, are of the split-skirt type, each having two compression rings and one scraper ring A Tecalemit full-flow filter is employed in the tubricadon system, which incorporates a gear-type pump supplying oil under pressure to all main, big-end and camshaft bearings The supply to the big-ends, via an oil feed in the crankshaft, also provides for jet lubrication of the cylinder walls, whilst oil from the front camshaft bearing supplies the timing chain The oil capacity is 12 pints, plus 2 pints for the Tecatemit filter, and the system is designed to run at 50-55 lb. per sq. in. pressure under normal working conditions.
Zenith Carburetter A Zenith down-draught carburetter is used, drawing its air supply through an oil-wetted gauze filter. It is fed with fuel by an A.C. mechanical pump from a 10-gallon tank on the near side of the chassis. This tank, like the 63-amp.-hr, battery, which is carried in a corresponding position on the off side, is mounted on brackets at the side of the chassis frame, Other engine details include coil ignition with automatic advance and retard of the usual centrifugal type, assisted by vacuum control The dynamo is of the 12-volt constant-voltage-control pattern.
Removal of the off-side portion of the three-piece detachable engine cowling gives access to the sparking plugs, distributor, coil, dynamo and dipstick. By withdrawing the corresponding portion on the near side, the carburetter and A.C. fuel pump can be reached. Oil replenishment is effected through a detachable cap in the valve cover and the radiator is filled through a cover plate in the fixed portion of the engine cowling.
The Borg and Beck clutch, which is 9 ins, in diameter, is of the single dry-plate type and has a frictional area of 66.2 sq. ins. The four-speed "crash" gearbox has constant-mesh third ratio. Overall gear ratios are 6.57, 10.91, 19.13 and 31.3 to 1. These ratios, in conjunction with the 32-in. by 6-in. Dunlop tyres, give road speeds of 14.85 rap.h., 8.93 m.p.h., 5.09 m.p.h. and 3.14 rup h , reapedtively, at an engine sneed 1,000 r.p.m. Reverse isof the same ratio-as first speed forward.
From the gearbox, the drive is taken by a Hardy Spicer open propeller shaft, with needle-roller universal' joints, to a spiral-bevel final drive. The rear axle is of the fully floating type, the bevel and differential assembly being detachable from the rear after the cover plate has been removed.
Hydraulic Shock Absorbers
Semi-elliptic springs are used front and rear, those at the front employing 12 normal leaves and those at the rear 11 main and three auxiliary leaves, all being shackled at the rear. A refinement, by no means universal on this kind of vehiele, is the provision of shock absorbers—in this case, of the Armstrong hydraulic double-acting type.
Girling brakes are employed with two leading shoes in both front and reardrums_ At the front, the meleading-shoe action is obtained by the use of duplicated operating cylinders, whilst at the rear, what would normally be the trailing shoe is provided with the Girling arrangement of bell-cranks and a strut to provide a leading-shoe effect. Adjustment is by means of snail cam adjusters at the front, and the usual Girling conical adjuster at the rear. The hand brake operates on only the rear wheels by means of a typical Girling layout of rods in tension, with a hanging compensator carried on the rear-axle casing. Drums of 12-in, diameter are Lpmployed on all wheels and the total facing area is 184 sq. ins.
A Bishop cam steering gear, giving a ratio of 16 to 1. and calling for 21 turns of the steering wheel from full lock to full lock, is employed. It is mounted on a stout outrigger bracket on the extreme front of the chassis frame, being connected to the steering arms by means of a Thompson drag-link and tie rod. The front axle is a toughened-steel drop forging of "I " sectioa, which changes to rectangular section from the spring pads to the steering swivels. Taper-roller bearings are used for the front hubs.
Body Capacity of 300 cubic it.
The body is steel panelled on a wood frame, with the interior panelled in wood up to a height of 2 ft. 6 ins. from the flOor; above that, protecting slats are provided. Wearing plates are fitted to the floor and at the edges of the door apertures. 'The floor length is 10 ft. -4 ins., and the width 5 ft. 8i ins., except between the square wheel-arches, where the width is 4 ft. From loading floor to ground is 2 ft. 41 ins., -capacity of the body 300 cubic ft., and weight of complete van 39 cwt.
All the doors are hinged to fold back flush with the body sides. At the sides, each aperture is 2 ft. 6 ins. wide and 4 ft. 71 ins. high. At the rear, the aperture is 5 ft. 2 ins wide and 4 ft. 101 ins. high.
The driver's cab is roomy and designed to promote comfort and ease of control. Forward vision is exceptionally good through the deep, slightly V-shaped, toughened-glass screen On the driver's side, the panel opens, and an -electric screen wiper is provided. The driver is also 'provided with a window in the partition between cab and body, and there are windows in the upper portions of the rear doors.
In addition to the van, an ambulance is also listed,
the chassis being identical with that of the van, except for a slightly wider track (5 ft. 2 ins.), larger tyres (9 ins. by 16 ins. E.L.P.), softer springs and an appropriate shock-absorber setting.
The driver's cab is identical, except for a high-grade finish in keeping with the remainder of the vehicle, as opposed to the normal " utility " finish of the van. At the rear, the double doors are arranged as in the case of the van, but disappearing steps are provided, which, when not in use, fold away to form part of the floor. At the side, a single door is positioned, screened.: by a partition, with the attendant's seat opposite. .
A wide choice of seating and stretcher arrangements is offered: On each side it is possible to have (a) a seat for six sitting cases, (b) a convertible seat for six or stretcher for one, (c) a single stretcher or a double stretcher. Various combinations of these are available.
Heating and ventilation have been particularly well studied. Two let-down windows of tinted glass are provided on each side, and there is a similar window in each door. In addition, there is a Clayton airconditioning plant, which draws air, through a Vokes filter, from a ventilator in the roof; when required, the incoming air can be heated (from the engine-cooling system) and a thermostat is provided in the interior of the body which can be set to control the• temperature between 45 degrees F. and 75 degrees F. Vitiated air passes out through an extractor in the roof.
Other details of equipment and finish include an interior light, separate door locks, and a floor covering of Magnesite (a composition of magnesium oxide with a wOodflour filler), laid to provide rounded "corners" between floor and body sides to facilitate cleaning. Provision is made to floodlight the rear step when necessary. The price of the ambulance complete, less stretcher and/or seating for patients, is £805.