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COMMERCIAL MOTOR
Recognized in Business Circles as the Leading Journal.
The Authority on all forms of Mechanical Road Transport,
WE briefly report the proceedings at the parade of commercial motor vehicles recently held at Man
chester. Page 278.
THE developments for 1928 in an important range of passenger and goods chassis by a leading maker are described by us after an inspection of the latest
models. Page 290.
WE describe and give line drawings of a new petrol-electric rigid-frame six-wheeled -chassis which has just been produced—the first of its kind in this
country. Page 279.
THE type of free-wheel for incorporation in the transmission line of a motor vehicle, and for which a position immediately behind -the clutch has been chosen, is described in this issue. It offers certain advantages of the system, but not all. , Page 282.
A. NEW steam-driven chassis, based upon a recently introduced undertype steam wagon by a well-known maker, is described by us this week. Those heavy components, the boiler and engine, being placed more to the rear, the weight is well distributed. Page 277.
THE latest information with regard to the Steam Wagon Demonstration which is being organized by the Steam Vehicle Committee of the Society of Motor Manufacturers and Traders in co-operation with The Commercial Motor -is dealt with in this issue.
Page 288.
A SIMPLE arrangement by which a steam ejector is included in a fitting for attachment to the water tank of a steam wagon, so that the water may at a moment's notice be used for fire-fighting or can be employed for washing down, is dealt with by us.
Page 289.
CONFORMING with the increasing demand for rapid-transit passenger vehicles, capable of a high degree of acceleration, a well-known British maker is bringing out several new models with six-cylinder engines. We describe the first of these in this issue.
Page 284.
MANY months ago we recommended the employment for cross-country duty of six-wheeled vehicles, driving on all six wheels. A British-built. chassis of this type has just been completed, and a feature of the design is that the drive to the forward wheels can be disconnected by the driver whilst the vehicle is running. We give a brief description of this new machine. Page 288.
New Routes for Motorbuses.
THE fact that the London area %is so largely reserved by reason of restricted routes under special legislation and Orders does not mean that nothing more can he done by new and old proprie tors within, say, a radius. The exact effect of certain fresh proposals for restriction is not clear, and we believe, when the Ministry _of Transport essays its next turn of the • curtailing screw, that there will be something akin to a public outcry.
Greater' London is far from being served on all its circular, connecting and cross routes. We consider that the .9:round between 10 miles and 30 -miles from Charing Cross offers fruitful scope.for such new routes, and at the hands of new owners It the old ones refuse to expand. Are Some or all of these old owners tied up by agreement? If not, why is it that Droinising routes in developed and developing areas between main thoroughfares remain unserved?
If, at angles of roughly 20 degrees from each other, one runs out on the map, with Charing Cross as the centre, from 15 to 20 diagonal lines for a distance of 30 miles in that many directions, there lies, with increasing freedom from Traffic Act restrictions the farther out one reaches after the first 12 miles, almost virgin ground—so .far as adequate bussing goes—between many of them. Rig vehicles may not be needed in all cases, we admit, but some types'of public-service vehicle are certainly wanted.
There is too much concentrating upon_ radial services and too little done as concentric working. Linking up the radii is no new feature, we know, but it is often neglected where there is unquestioned call for it if the public convenience be the chief consideration. That, too, he it. ob.s.erved, should coincide with the obtaining of sufficient revenue to pay. We _cannot agree that all working at a radius Is "thin."
We urge prompt attention to this matter of more inter-suburban services. Whilst linking suburb with suburb, such services can, by giving a choice of user between several electrified or other radial railway systems, anticipate, if not actually rely upon, a share of the traffic to and from the centre. These factors, of course, have their applications in and near all great cities. They do not concern London alone. The main traffic stream may be through and to the heart of all cities, but the planetary movements are not to be ignored.
The Progress of Servo Braking.
fr1HE forthcoming Commercial Vehicle Exhibi tion at Olympia will reveal the remarkable progress which is being made in the employment of servo devices for assisting the driver in applying the brakes of a vehicle. As a matter of fact, we shall not be surprised if something like 90 per cent. of the heavier vehicles are shown with some form of this equipment—in the majority of cases of the vacuum class.
This will be a long step in the right direction, and one which has for some considerable time been advocated by this journal, for we have realized that with more powerful engines providing greater vehicle speeds and rapid acceleration it is almost essential for the safety of the vehicle itself and other users of the road that more power than can be exerted by the individual human being should be available for applying the brakes. The addition of front-wheel brakes by itself does not necessarily increase the total braking effort, unless more power can be provided at the point of application. The chief factor to be considered in this connection is the total area of braking surface, together with the efficiency of the connections by which the power is conveyed to the brake shoes. It may be that When a vehicle is comparatively new and thoroughly well lubricated the brakes will be quite easy to operate, but after a short time. when the inevitable dirt has increased the friction at the various points of relative movement, the brake application may become considerably more difficult. Whilst welcoming the addition of servo devices we Would emphasize the importance of laying out the braking system in such a manner that if by any chance the servo fails in its duty the driver will still be able effectively to operate the main brakes and not have to fall back upon the handbrake only.
Another Six-wheeler Development.
I-N February of this year we put in a strong .editorial plea for experiments to be carried out with six-wheelers driving by all wheels. We pointed out that both the half-track machine and the ordinary six-wheeler can be stalled under certain conditions, such as when the front wheels are forced against a steep bank or where the driving wheels or tracks are on a surface, such as soft clay, giVing but little adhesion.
In this connection we are glad to note that at least one British maker has come forward with an all-wheel-driven six-wheeler possessing some remarkable characteristics, one of which is that the front-wheel drive need only be employed in emergencies or when braking on all six wheels is thought essential. This avoids the enforced use of a differential between the front and rear drives. Such a Machine as this has mobility tol an exceptional degree under the most adverse circumstances. The driving front wheels, when forced against a steep bank, do not press in, but . merely lift the front of the vehicle over the obstruction, and, having no differential between the drives, spinning of either the front or the rear wheels does hot necessarily result in bringing the vehicle ..to a standstill. Driving on all six wheels is hardly necessary for ordinary road use, but it renders a vehicle even more independent of the roads than the Standard type' of rigid-frame six-wheeler.