Napier Developments.
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First Particulars of a World-famous British Maker's Latest Models.
A One-ton Van Complete with Body and Tires for £400.
Not any name enjoys a higher reputation in motor manufacture than does that of Napier—D. Napier and Son, Ltd., of Acton Vale, London, W., which company is now doing its commercial-vehicle business direct from the works. The deserved popularity and widespread use of Napier taxicabs and light delivery vans will be matters of common knowledge to many readers of THE COMMERCIAL MOTOR, hilt it will be news to not a few of them to know that Mr. Montague S. Napier, so far back as the year 1801, delivered a 25 h.p. five-ton petrol lorry to Mark Mayhew, Ltd., () f Battersea. In spite of the large amount of attention demanded by the huge sales of Napier cars, Mr. Napier has never allowed his interest and careful study of the commercial-motor side of the movement to flag. That interest, it should be added, has not by any means been limited to mere observation, as is proved by the large numbers of taxicabs and van chassis which have been made at the Acton works during the past few years.
It. was our pleasure, one day last
week, to spend several hours at the Napier factory, and we were on that occasion afforded every opportunity for close inspection and scrutiny of the detail parts, complete units, and finished chassis for the range of 12-cwt. and one-ton models which are now relady for the market. That visit, which confirmed all that we had previously heard about the high-grade materials and excellent workmanship which alone enter into Napier construction, was followed by a Wal run with a. loaded one-ton van, both in the immediate vicinity of the works, and through some of London's busy traffic thoroughfares. Its running and facile control justify our commending it most favourably to intending purchasers. Handled by the writer for the first time, the van responded to every call.
A One-tonner Which Will Make Its Mark.
The one-ton Napier chassis has been most-carefully proportioned throughout to bear a total imposed load of 27 cwt. There is, ac cordingly, the necessary margin (for body and driver) to allow the conveyance of a net useful load of one ton. The whole of the illustrations which accompany this article are reproduced from photographs of a one-ton chassis, but attention is also drawn to the principal points in respect of which the 12-cwt. model differs from the larger one The four-cylinder Napier engine has a bore of 31 in., and a pistonstroke of 5 in. The cylinders are arranged in pairs, with the camshaft and all gearing entirely enclosed in an aluminium and dustretaining case ; the interchangeable inlet and exhaust valves are operated from one camshaft, and are on one side of the engine. The ignition is by a Bosch high-tension magneto, which is well arranged for rapid detachment when necessary: the lubrication is by a gearwheel pump, of ample dimensions, placed low so as to be always flooded, which forces the oil through the hollow crankshaft to the crankshaft bearings and pins, an overflow tap and an accessible strainer
being included in the circuit, whilst a dial "tell-tale " faces the driver. The Napier carburetter with pedal control of the throttle valve has proved capable of yieldjog a performance of 16 miles of running, under full load, per gallon of petrol. It will be observed from the engine illustrations, that therrno-syphon cooling is embodied in the design, but a centrifugal pump is additionally fitted as part of the water-circulation system. Should it at any time be thought advisable to eliminate the pump, the connections for working on the thermo-syphon system can be made without difficulty or expense.
Retention of Combined-unit Construction.
The Napier practice of unit construction, in which the engine, clutch and gearbox are combined, is a noticeable feature of this onetonner. The complete unit is supported at the back from one point, about midway along the chassis, as may be seen in one of the illustrations, from a main tubular cross member, and at its forward end, direct to the frame, by two crankcase " feet." The transmission of power from the crankshaft is through a plate clutch with flat discs, a three-speed-andreverse spur-tooth gearbox, and a ivorm and worm-wheel drive to the
live back axle. A free use of t.-.1Ier bearings has been made in the gearbox, whilst both the fixed and sliding gears are mounted on ca.stellated shafts. The changespeed lever and the "gate " are carried upon a special extension arm on the gearbox casing, through which tubular arm the change-speed shaft works.
:Back Axle, Frame and Wheels.
The back axle, in accordance with best design, is arranged so that only the drive is taken by the shafts, the load being borne by the encasing tube. The worm and worm wheel have been designed to provide the maximum of driving eerd act, and it will be noted that the worm shaft is disposed above the worm wheel. Thrust and other details through this important unit are in accordance with the latest practice and experience, and we would draw special attention to the employment of chilled bronze sleeves on the journals of the back and front axles. These sleeves in the case of the front wheels are mounted on the axle itself, and form a floating bearing between it and the wheel hub. In the case of the back wheels, a similar floating bearing is used, but, instead of its being mounted on the axle, it is mounted on the axle-casing, thus relieving the axle itself of any bending strains, to which feature we have already directed attention.
The frame is of pressed channelsection steel, and is stiffened by a sufficiency of tubular cross mem
bers. Long and flexible springs, of ample strength to withstand the strain of usage over rough roads, are employed, and the back springs are fixed at their forward ends. The road wheels are of the artillery type, with oak spokes: the front wheels are fitted with Dunlop pneumatic tires of 815 mm. by 100 mm. ; the back wheels with a. single Midland band-type tire of 900 mm. by 100 mm. The road speeds are worked out, on the basis of a rear-axle reduction of 5.6 to 1 and the engine running at 1000 r.p.m., to give running at 4.3 m.p.h., S m.p.h., and 18 m.p.h., with a reverse at 4.3 m.p.h.
Special care has been given in the design to the matter of brakes, and two independent sets, of the metal-to-metal type, are available for the driver's use. The drum brake on the main shaft, which is located immediately behind the gearbox, is controlled by a pedal, whilst the internal-expansion-type brake, which acts on drums on the hubs of the back wheels, is controlled by a hand lever. The back wheel brakes are particularly well protected from dust and mud. A stout sprag is also fitted, direct to the right-hand frame member.
For the guidance of intending purchasers who are interested to have before them some of the principal dimensions, with a view to the choice of body, we may mention that the width of the frame is 32 in., and that the usual extreme width of body is 5 ft. 2 in. The length of body' behind the driver's seat, without introducing undesirable overhang, is 6 ft. 7 in. In the van which we tested on the road, there is comfortable headroom for an ordinary porter to stand on the floor of the vehicle and to handle packages, whilst t front seat is commodiously wide. The amount of rake that has been given to the steering post, the relative positions of the changespeed lever, the hand-brake lever and the hand throttle-fixing of the control on the dash have evidently been carefully studied by the designers, for they present a remarkable degree of convenience from the driver's standpoint. The petrol tank is placed under the driver's seat, and the feed to the
carburetter is by pressure. The hand pump, which is employed to provide the initial pressure in the petrol tank, or to maintain it on occasion, is neatly hinged to the
dashboard, and the valve is so arranged that it opens when the barrel of the pump is inclined towards the driver's seat, closing again when the pump is returned to the vertical position and its retaining clip. The general finish of the metal parts attached to the bodywork, the axle caps, brackets, etc., is in brass, and an extra charge of £8 is made if nickel finish be specified. The chassis price of 2350 includes the standard tires which are mentioned above, two brackets for side lamps fitted to the dashboard, one tail-lamp bracket at the back, and certain specified tools and accessoriell. The vehicle, with a good-class box-van body, complete with lamps and accessories ready for the roads, comes out at a price varying from £395 to 2400, delivery to be taken at the Napier Works, Acton, W.
This one-ton van, which is the direct outcome of experience with other commercial-type models over many millions of miles of running, is one which we feel confident will give satisfaction to purchasers. and will prove to be capable of carrying out its work efficiently at an inclusive cost per mile of .service not in excess of 5d. per mile.
The I2-cwt. Van.
The engine, gearbox and final drive of the 12-cwt. van are the same as in the one-ton van, except that the 12-cwt. van has a bevel drive to the back axle instead of a worm; the same general design is evident. Neither the axles nor the frame are so heavy, whilst the. overall dimensions are smaller in proportion to the intended smaller load of 12 cwt. net. The road wheels and springs are smaller, whilst Dunlop pneumatic tires are found both upon the back and front wheels. This van chassis, including 815 rum. by 105 turn. Dunlop tires to all wheels, is priced at £315 ; it is a model which should. appeal to many owners and intending owners whose requirements can be met by a vehicle of the capacity indicated, but who. are desirous to have a machine which is capable of travelling at speeds considerably in excess of those which are specified for the one-tonner.