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A DOUBLE-DECK n( BUS FOR LEEDS,

20th September 1921
Page 12
Page 13
Page 12, 20th September 1921 — A DOUBLE-DECK n( BUS FOR LEEDS,
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IN OUR issue of September 6th we dealt briefly with the experience gained by the Tramways Department. of the Leeds Corporation with its single-decker trolley-bus, and referred to the fact that plans were in hand for the construction of further cars of similar design and also for double-deck vehicles -to accommodate about 60 passengers.

One of the double-deckers is now completed and is undergoing a series of tests. It has a total carrying capacity of 59 passengers, 28 being carried inside and 31 on the upper deck, which is enclosed in the manner now almost universally adopted on tramcars. The chief difficulty when covering the top saloon is to keep the overall height within reasonable limits, and this has been cleverly accomplished in the present instance by the use of a " dropped chassis."

The whole of the driving mechanism is carried on a swivelling forecarriage at the front. of the bus, and immediately above and behind this is placed the driver's compartment,; thereafter the main frame members are given a " drop " or " set " downwards of 2 ft., and upon this lowered platform the body of the bus is built. The result is a particularly stable vehicle, which in no -ordinary circumstances would beable to turn over. The height of the rear platform from the ground is only 15 ins., whilst the. centre of gravity of the vehicle fully loaded is about 5 ft. above the ground level.

A Rapidly Detachable Power Unit.

The "front drive' system, which makes the above arrangement possible, is the patent of Mr. G. A. Bishop, and is manufactured under licence from the Electric Traction Co., of Hepworth Chambers, Leeds. Two electric motors of 25 h.p. each are carried on the foreearriage, which is separately sprung and attached to the main frame by six bolts only--a feature of the system being the ability to remove and replace this forecarriage in a few minutes. This is an important point where a tramway company desires

. to keep a small number of trolley-buses in practically constant service, as it is only .necessary to have one or two spare forecarriages which can be slipped into place whenever required.

This is a development upon the system adopted by the Maintenance Depar:tment of the London General Omnibus Co., whereby the power unit and transmission and the steering constitute four units—engine, gearbox, back axle, and steering gear--either of which can be replaced in the. garage in a matter of a few hours. The aim, of course, is to prevent the vehicle from being held up in a garage—its earning power lying dorniant—whilst a repair had to be effected. In the early day :s of the London buses, vehicles were often in garage for two or three weeks for repair to mechanism. By the creation of a pool of spare units from-which to effect immediate replacements the loss of earning power is reduced to a minimum.

Central Station Power Simplifies .Design.

The concentration of the whole.of the power transmission and steering in one unit in the case of the Leeds trolley-bus is rendered possible by the fact that the power is -developed at a generating station and can he supplied to the vehicle through moulded cables and trolley gear. To arrive at the same advantage with a petrol-driven vehicle, the engine would need to be added,thus greatly increasing the load on the front axle. The system has been tried for pleasure and goods-carrying vehicles in the United States--we recall the ill-fated Christy front-driven car—but has never been developed into a commercial proposition except in the case of the Chicago bus., to which we will refer.

We are not able yet to give the axle weights of the Leeds double-decker, but hope to be able to do so in an early issue. They will be extremely interesting, especially in comparison with those cf-an S-type. Lendon bus.

c13 Single-deck vehicles of a somewhat similar pattern have (as we have already recorded) been running for some little time at both Leeds and Keighley, but the new vehicle is the first to embody the Bishop system, with the interchangeable forecarriage and dropped chassis referred to above. The covering in of the top deck in the Leeds blis is an enormous advantage. It is only rendered possible by the concentration of the transmission system on the front axle. The rear axle merely has to carry its load, the rear wheels taking a share of the braking strains. Thus, the chassis behind the cab is left clear and the frame can accordingly be dropped so as to give an unusually low loading line. Our side views of the bus show how law is the platform of the lower dack—in itself an enormous advantage to those passengers who have lost activity and joint flexibility. Many of these passengers are lost to the services which do not cater for them, yet they all constitute potential additional revenue, and they invariably travel during the slacker hours of the day, so that ths business is worth aiming at, if it can be secured by improvements to the vehicles. The trolley poles on the Leeds double-decker are supported upon the upper deck, their support not being carried down to the chassis frame. This arrangement constitutes an added strain upon the body, the upper part of which is, naturally, extremely light. It will be seen from the front view of the vehicle that the roof is supported by additional pillars in front to meet this strain. • We have long contended that an effort should be made to cover in the upper decks of buses. When the weather is bad, the exposed upper deck is either useless or imposes unfair discomfort. on passengers. In the rush hours, when passengers simply must travel, it is not an unusual thing to see an upper deck load of passengers all standing simply because the seats are wet. Yet, standing, they are exposed still further to the fury of the elements.

Top-deck Cover in Other Cities.

The only sustained attempt to provide suitable cover for upper decks was made by the Fifth Avenue Coach Co., of Now York, which is under the charge of a Britisher, Mr. G. A. Green, who has closely followed all that has been done by bus-operating concerns in this country and who for that purpose is a frequent visitor to these shores. On the New York buses Mr. Green introduced a three-hoop Cape cart hood, the hoop sticks being brought to a central pivot on each side of the body, the cover coming down on either side about e ins., so leaving about 18 or 20 ins. open to the elements. The front has two celluloid windows and affords complete protection from head, winds and rains. The rear of the hood has a window on one side and an. opening at the head of the staircase.

The Fifth Avenue Co.'s buses, and also the new buses for Detroit, are built very low, the platform being about 15 ins.76ff the ground. This gives a low centre of gravity and assists in the matter of the upper deck cover. The designers of the buses in use on London streets have not yet secured a chassis that would permit of dropping the frame and a thorough lowering of the whole of the bus body. They are frankly nervous of raising the centre of gravity by the provision of an upper deck roof and they do not favour the Cape cart hood because of its fragile nature. In London there are many low bridges over the highways on some of the routes.

It may be remembered that in the city of Chicago there is employed a type of bus which might in some respects be regarded as the forerunner of the Lends d.ouble-decker in so far as its chassis arrangement is concerned. The power unit (in this ease an internal-combustion motor driving on to the front wheels) is all forward under the bonnet, behind which is the driver's cab, giving him ample protection from the elements (as will be seen from our accompanying photographs, the Leeds trolley-bus is excellent in this respect). The frame behind the cab is dropped, and the floor of the vehicle is brought down SO that there is but 12 or 15 ins, clearance between it and the ground. The Chicago bus is double-decked, but without any roof cover to the -upper deck. "

The Way Out for Tramway Departments.

We commend to all tramway managers a careful study of the Leeds double-decker, because the difficulty of replacing worn permanent way at presentday costs is so great as to put it beyond the region of practical politics, and with a generating station in being, and the small initial cost' ands:long life of the overhead wires and their supports, the possibility is provided for the extension of many of the present tramway systems by the employment of trolley-buses. The commercial-vehicle industry is quite capable or building the vehicles, and certain makers are already preparing to add the type to their catalogues.

We are confident that, in the course of a very few years, a large number of this type of vehicle will be on the road.


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