Correspondence
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'Cars which do not Stop.
The Editor, "THE COMMERCIAL MOTOR."
Sir :—I have read, with mixed feelings, the advertisement of Commercial Cars, Limited, in which it is stated that the company's cars do not stop. I have, perhaps, put the wrong construction upon this very smart advertisement, but, if not, I should like to ask how the drivers deliver the goods in the circumstances ?—Yours faithfully,
" PUZZLED."
Birmingham.
About Motorcabs.
The Editor, "THE COMMERCIAL MOTOR."
Sir :—I have read with interest your extremely instructive articles appearing in " The Motorcab Special," and, as my new centrally-situated depot is almost complete at this address, I am open to discuss any scheme which might be put forward touching the above subject. I would give special attention to propositions for handling the maintenance of good-class cars not as yet fixed up here.—I am, .yours faith fully, IIuBF.az Mummy. 72, Harcourt Street,
The Lubrication of Ball Bearings..
The Editor, "THE COMMERCIAL MoToa."
Sir :—We notice an article in your edition of 7th May, on the lubrication of bail bearings with graphite, and note with interest the reduction of friction due to this. We think, however, that it is only fair to your readers to point out that it is our experience that this form of lubrication is bad from the point of view of the life of the ball bearings. We have come across a number of cases where the bearings have been lapped out owing to the very fine abrasive action of the graphite. We have also heard that the same result has been found by a number of makers and users of motorcars. Of course, we do not know the quality of the graphite lubricant used.—Yours faithfully, TILE HOFFMANN MANUFACTURING CO., LTD.
Chelmsford, G. F. BARRETT, Director. 7th May, 1908.
One Possible Cause of Tramcar
Accidents on the Level.
The Editor, " THE COMMERCIAL MOTOR."
Sir :—With reference to your able editorial on " London's Dangerous Crossings," I should like to remark that, in my humble opinion, one of the chief reasons for the many lamentable accidents at cross-roads where there is heavy electric tramcar traffic is the fact that the intersecting points of the rails are " dead." The car has to be travelling at a, comparatively high speed in order to get over the points without " sticking." All traffic should ease up at dangerous corners, but the I.C.C. tramcars cannot do so. Piccadilly Circus, with its enormous amount of traffic, is safer to cross than the Holborn Town Hall corner at busy hours of the day. At the former spot, nearly every vehicle, from the motorbus downwards, travels at a moderate pace, and so the average, level-headed pedestrian can cross in perfect safety, but, at the Town Hall, if one steps out from behind some other vehicle, there is generally a huge tram hurtling along to rush the " dead " points. The pedestrian steps back in a hurry, with the probable result that the next day the papers announce that another person has fallen " a victim to the death-dealing motorbus."
The " Elephant and Castle" is another place where the trams make the roads positively unsafe to other vehicles, as well as to pedestrians. If, the L,C.C.'s vehicles could only move slowly across main roads and intersecting points, then there would be fewer accidents to be attributed to the muchmaligned -motorbus.—Yours faithfully, " EQUALITY." London, S.W.
gth May, 1908.
Tramcars in Processional Order.
The Editor, "THE COMMERCIAL MOTOR."
Sir :—The apathy of the London public towards the gradual monopolisation of the chief roads of the Metropolis by the leviathan double-deck tramcars of the L.C.C. is amazing. Your short leader in this week's number draws attention to the " Death-trap corner " which the Council has established with fiendish care at the junction of roads outside the Holborn Town hall. In this connection, may I take advantage of your offer to reply to queries, legal and otherwise, by enquiring whether, when tramway authorities are invested with their powers, any restriction is imposed on them as to the distance apart at which tramcars may run or stand. 1 ant under the impression there is. In the interests of all other road users, it would be well to insist that, say, every two or three hundred yards a gap should be left in the solid wall of tramcars which often stretch down the centre of all the roads leading from such crossings as that you instance. Drivers of tramcars frequently proceed slowly, in congested traffic, three in line, with their buffers touching, much to their own amusement, and the inconvenience of other drivers and foot passengers. I know it is no part of your propaganda to help to embarrass the tramway authorities by drawing attention to their shortcomings, but, surely, it is time that this assumption of monopoly of right of way on our public thoroughfares, by the tramway autho-. rities, be disputed tooth and nail by all other users of the.
roads. There still remain a few other users, although most of them, nowadays, have to crawl through the back streets.--Yours faithfully,
Norwood. " PULINLAN-PEDESTRIAN."
" [A bye-law was made, on the 6th August, 175, under the provisions of the Tramways Act, 1870, according to which, subject to a penalty not exceeding 40s. for each offence—. No carriage using a tramway shall follow another carriage using the same tramway at a less distance from such other carriage than 100 yards, except at junction points and on single lines of tramway." We are unaware that this bye-law has ever been repealed, or that the L.C.C. Tramways Acts can be held to over-ride it.—End Petrol-electric Transmissions.
The Editor, " THE COMMERCIAL MOTOR."
Sir :--In reply to " Interested," I will try to explain what 1 meant by a tremendous torque. Supposing we have a train headed by two locomotives, one steam and one electric; if the steam driver opens his regulator, and the electric. driver his controller at the same instant, we have the combined pull of the two engines to start and accelerate the train. So with the " Auto-mixte " bus. The petrol motor. correspondsto the steam loco., the dynamo to the electric. loco., and the weight of the bus to the train. The crankshaft of the engine, the armature shaft of the dynamo, and the propeller shaft of the bus are direct coupled, the former two by a positive coupling, and the latter by a magnetic clutch. On starting the bus, the petrol engine begins to pull ; the current from the battery goes to the dynamo, and drives it as a motor, which also exerts a good pull ; thus we get the combined force of the two, as with the two loco:_ motives and the train. The dynamo, when acting as motor; is protected by a fuse from overload. The acceleration is
swift and entirely free from jerking. •
Mr. Frost Smith makes a mistake : " Micky,' as he• affeotionately calls me, is not an Irishman, " Auto-Mick being a nickname bestowed on the writer for obvious' reasons. As to the " cap fitting," it is not for me to say. The abuse was certainly not imaginary, as anyone who read Mr. Frost Smith's paper will have seen. I only mentioned that I was one of the class to which he so con; temptuously refers. It seems very unfair to condemn the. whole of the London drivers because Lhere are a few black. sheep in the flock. However, this is not a discussion on drivers, so 1 will get back to facts.
Mr. Frost Smith remarks on my driving experience with:
the " Auto-mixte " bus. I beg to inform him that, on nearly every occasion, the bus was driven in a manner as near actual service conditions as possible. I very often went where I could find something approximating to London : to Birmingham, for example, which is a busy city, with congested traffic, electric tramcars, bad hills on which to stop and start, and other "echoes of London." I have, in fact, been to London itself twice; also to Brighton and Newhaven. I have encountered bad _hills, but on every occasion the " Auto-mixte " bus:has behaved itself admirably, climbing hills of i in 8. Mr. Frost Smith says I talk about London buses, and claim a knowledge of their efficiencies, etc., and asks for figures. A locomotive driver knows his engine, its good points, and its faults; most motorbus drivers can say the same of the machines they are in charge of—witness the letter signed " Hammersmith Bridge " in the " Drivers News " page on 30th April. I know the weaknesses of buses I have driven in London, and, as I have failed to find anything of the sort on the Auto-mixte," I conclude it is a much better bus. Anyhow, I know it is easier to drive than any I have hitherto handled. I have all the figures Mr. Frost Smith requires, but the company does not wish them to be made public at present. I can state, however, that they fully justify any claims I have made for the " Auto-mixte "buses, and, when the time comes for them to be put into service, and the fig-ures are given, they will somewhat astonish Mr. Frost Smith, and any other sceptical persons. The description of the" Auto-tnixte " has already appeared in " THE COMMERCIAL MOTOR," SO there can be no harm in giving Mr. Frost Smith the weight of the battery. it is only a small affair under the driver's seat, weighs about 5i cwt., and contains enough ampere-hours, when used solely as a means of supplying power, to drive the bus five miles. Once, when-lout for a short spin, we ran out of petrol about i mile from Kenilworth, so we drove the bus three miles back to Coventry on the battery alone, using the dynamo as a motor. Supposing Mr. Frost Smith compares the weight of our battery with -the weight of the two outside motors on the " S.B. and S." chassis? If, as he says, it is far better to have a two-speed gearbox and a Dennis live axle, why then does he not adopt it? Surely that would be far lighter than having a species of electric tramcar careering around, carrying its own power station on board? He cannot apply that description to the " Automixte," as immediately any extra power is needed it is there ! Our " power station" automatically reverses itself, and gives out direct mechanical energy to assist the petrol engine. Mr. Frost Smith does not seem to understand that our battery is simply a means of picking up the excess power given off from the engine, as when standing at points, running downhill, braking, etc., storing it up as electric current, and giving it out again when wanted.
Our engine is a standard Coventry Daimler, the name being a guarantee of its good quality. My figure of speech was intended to show that any engine troubles would not necessitate hanging the bus up at the roadside, as would be the case with the " S.B. and S." if its engine failed. I noticed one big mistake he made in the paper on " PetrolElectric.Transmissions." He said the" S.B. and S." motors could not be over-loaded, but that an electric tramcar driver, having the full power of the generating station at his command, could do his motors serious damage. Nothing of the sort. Surely Mr. Frost Smith should know that, on an electric tramcar, train, or loco., in the circuit between the controller and the motors, are one or more automatic switches, or circuit-breakers, actuated by electro-magnets. When the rush of current exceeds a certain amperage, these switches will immediately fly to the "off " position, cutting off all current and preventing the motors from overload and burning. The car cannot be started until they are replaced in the " on " position. These circuit-breakers will very often " blow " off when starting up on a rising gradient, as the motormen tend to notch up too quickly.—I am, Sir, respectfully yours, " AUTO-MICK. "
Coventry.
The Editor, "THE COMMERCIAL MOTOR."
Sir :—I have observed the correspondence between Mr. Percy Frost Smith and other gentlemen on this subject. It would be interesting if Mr. Smith were to give replies to the following queries, in respect of the petrol-electric vehicle, constructed according to his and Mr. Stevens' patents, which is now running for Thomas Tilling, Limited :— (a) What percentage of lost journeys has this bus experienced?
(b) Have the motors been changed?
(c) Has the dynamo been changed?
(d) Has the engine been changed?
(e) How many times have the motors either partially or entirely burnt out?
(f) What is the actual petrol consumption per mile? (g) How often has the bus been stopped by the police for excessive noise?
(h) How much time has been booked against the vehicle, on the average, per night?
(i) What is the total weight of the vehicle? Yours faithfully, London. "ENGINEER,"
Impressions of a Visitor.
The Editor, "THE COMMERCIAL MOTOR."
Sir :—I was in England, at Easter, after a considerable absence from my native country; and one of the things that struck me was the greater use made of the commercial motor vehicle. I spent most of my holiday in the south and west of England. Now, these regions are proverbially less go-ahead thaw the north and Midlands, yet I observed that the motor is dusting the horse in the south to a considerable extent. Motorbuses have sprung up, so to speak, in surprising numbers, both in town and country, and the economical advantages of the self-propelled van and wagon are evidently being appreciated. What, however, I missed was the tnoefarcab. True, there were plenty in London, but they were wanting in the Provinces I visited. In one important centre—Bristol—I did not see a single one. The capital of the west may have motorcabs, but I, as a visitor, who would have been glad to charter one, could not find them.—Yours,
etc., " Autos." Paris.