ALBION'S NEW FORWARD-DRIVE BUS CHASSIS.
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With a Low Platform Level and the Driver Placed Beside the Engine, a 32-seater Bus is Provided on a 16-ft. 3-in. Wheelbase.
;EW motorbus chassis, with a low load-line and with the driver's position taken right forward and placed beside the engine, has just been prepared for the market by the Albion Motor Car Co., Ltd., Scotstoun, Glasgow. It is a development from the " model 26," which was introduced about a year ago in the form of a 28-seater bus and which, it will be remembered, received its _christening in the shape of a remarkable non-stop return run between Glasgow and London.
The model 26 series included (I) a chassis with a 16-ft. wheelbase, 'which would accommodate a body seating from 28 to 30 passengers ;•(2) a shorter chassis, which would accommodate a 24 to 26-seater bus on a wheelbase of 14 ft. 4 ins.; (3) a chassis with a 14-ft. wheelbase, which would accommodate an 18-seater coach with a single-step entrance; and (4) a chassis with an 11-ft. 3-in. wheelbase accommodating a14seater coach.
The new chassis has a wheelbase longer than any In the series, viz., 16 ft. 3 ins., and it is designed io provide a maximum seating capacity of 32, thus bringing the chassis up to the full limit of the licensing classification.
Whilst the new chassis is based on the model 26 series and has a dropped frame similar in type to that incorporated in the vehicles of that model there are differences in detail from the chassis which had been employed for the full-bonnet type machines.
The type of power unit is the same. On an R.A.C. rating of 29.8 h.p. the engine develops 60 b.h.p., and it is now generally known as the 30-60 h.p. engine. It Is four cylindered, having a bore of 41-5r, Ins., the piston stroke being 4/ ins. We described this power unit in our issue of October 13th, 1925. The design is clean and straightforward in every way, the four
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cylinders being cast en bloc, the heads, however, being in pairs and, with their gaskets, being interchange able. All the valves are on the near side of the engine, their stems and operating gear being duly protected by cover plates. The magneto and electric starter are disposed on the near side of the engine, whilst the lighting dynamo is driven from a shaft on the off side. Pistons cast in aluminium alloy are employed, having full-floating pins which are located by a patented method consisting of duralumin studs drawn inwards by the action of a compression spring. The crankshaft is supported in three bearings of ample dimensions, the centre bearing—that \which always suffers the most from wear—being the largr..zt bearing.
Force-feed pressure is used for lubricating the engine, the crankshaft being drilled, and no troughs being employed. The oil is drawn through a filter of large dimensions, the heavier portions of the sludge dropping into a small sump.
Rather an unusual feature about the .Albion engine is the fact that the cylinders are inclined from the vertical to the extent of about four degrees, which has assisted the designer to give a combustion chamber of efficient shape, whilst the cylinder heads are kept horizontal.
Accessibility of every one of the details is a feature of the Albion -engine and its auxiliaries, and this accessibility is not lost in placing the driver's seat beside the half-bonnet. For instance, the carburetter,
Which is a Solex, can be disassembled, examined and replaced in less than five minutes; the dynamo, although on the off side of the engine, can be exchanged for a new one and rewired in 10 minutes. Without any special lifting tackle and with the assistance merely of a snatch block and of a piece of chassis frame the engine has been taken out of the chassis
and replaced in seven hours from the time that the engine was running to when it was once again running.
Great attention has been given to the matter of ease of control and to the steer:ng. This latter has ball or roller bearings at all main points, including the pivot pin top bearing. The steering is particularly light, even under conditions of Overload. The levers for changing speed and for applying the hand brakes are well placed in relation to the driver's seat and are easy to operate.
Mounted on the scuttle behind the radiator, and cut to allow the passage. through it of the steering column, is the instrument board carrying the oil indicator, switch and instruction plate, whilst immediately to its right is the mounting for the Pyrene fire-extinguisher.
The power is transmitted through..a single dry-plate clutch, with. Ferodo. rings On the flywheel. and also on the pressure
The Pedal • is extremely.light in action so as to reduce fatigue to the driver .when driving for long periods • in traffic.. Two adjust. ments are provided for the clutch, one by altering the fulcrum of the toggles ml the other on the pedal.
The gearbox is separate from the engine with the Albion geartype universal joint next to the clutch and a single Hardy , joint between the clutch and the Oarbox.
The engine is mounted at three points on the frame, but the gearbox at four points on the sub-frame: Four speeds forward and a reverse are given, the gear ratios being: top, direct ; third, 1.65 to 1; second, 2.94 to 1; first, 4.88 to 1, whilst the final, drive ratio is 6.25 to 1, although a different ratio can be supplied should a vehicle be intended for severe service.
Behind the gearbox is the transmission brake with a drum 13 ins, in diameter and having a face 4i ins. wide. The Shoes are externai-contracting, this brake being foot applied.
The propeller shaft is divided, with a Skefko selfaligning bearing at the centre, the universal joints being of the Hooke type and tieing protected from the entry of dirt and water by spring-held spherical covers. The rear portion of the propeller shaft is able to slide on its forward end on 'splines, and, in order to give as nearly as pOssible a straight-line drive under load, the engine and gearbox are sloped. . The final drive is taken through an underneath worm made by David Brown and Sons.
. Taper roller bearings are used throughout the wheels, and the rear axle is full-floating, allowing the final drive and differential gearing to be lifted after withdrawing the axle shafts.
The clearance under the vehicle up to the back axle is' 11 ins, and below the back axle (with the tyres slightly compressed under load) 6 ins.
The standard tyre equipment is -36-in. by 6-in. singles on the front wheels and twins of the same size on the rear' wheels, a spare wheel complete with tyre being included with the equipment.
Semi-elliptic springs are used throughout, those for the front axle being 42 ins. long and those for the rear axle 60 ins., the riding under both light and full load being astonishingly good.
Much attention has been paid to the body suspension, and, as our illustrations show, a strong cross-member is taken right across • the front body space of the chassis, and this is built into the body structure, so that there is no possibility of the body working,
thereby causing noise and rattle. "
The petrel tank is carried slung from the off side of the frame underneath the body, and throughout the design of the chassis and body the regulations proposed by the 'Departmental Committee have. been observed.
The frame is sloped downwards in a straight line immediately from below the radiator to a point in line with the gearbox, from which point it assumes a horizontal line. It is upswept over the beck axle and dropped to a further 61 ins, for the platform , at the rear of the back axle, The first bus of the type (shown in the accom
panYing illustration) has now been run in actual service for a distance of 10,000 trifles. It has given every' satisfaction and it shows a gratifying economy both as regards fuel and oil, the good figures that have been recorded in respect of consumption being a. natural reflex fromthe light weight of the chassis, which, less ‘fuel oil and water, is 2 tons 11 cwt.