AT THE HEART OF THE ROAD TRANSPORT INDUSTRY.

Call our Sales Team on 0208 912 2120

Correspondence.

25th July 1907, Page 18
25th July 1907
Page 18
Page 19
Page 18, 25th July 1907 — Correspondence.
Close
Noticed an error?
If you've noticed an error in this article please click here to report it so we can fix it.

Which of the following most accurately describes the problem?

Vapour Lock in Petrol Feed Pipe.

The Editor," THE COMMERCIAL MOTOR."

Sir :—Some time ago I increased the capacity of my petrol tank, and 'so brought its bottom level below that of the jet in the carburetter, and consequently I had to fit a pressure feed. In carrying out these alterations, it was also necessary to alter the position of the petrol feed pipe, and I brought this in a somewhat sharp curve over and close to the exhaust pipe. I immediately found that, when the engine was allowed to run slowly, the carburetter gradually emptied, and would not refill, although I had considerable pressure on the tank ; on the other hand, if I kept the engine ooastantly racing, I experienced no such difficulty. It took me some little time to ascertain the cause of this trouble, which finally turned out to he that, when the petrol was running quite slowly through the, feed pipe, a vapour lock formed in the top of the bend over the exhaust pipe, whereas if the engine raced, the more rapid flow of petrol kept it sufficiently cool to prevent this vaporisation. The trouble was immediately got over by taking the feed pipe in a gradual. slope below instead of over the exhaust.

As I heard from Sir Boverton Redwood the other day of a motorist suffering with this, what seemed to me inexplicable trouble, I thought my explanation might be of interest to some of your readers.—Yours faithfully, .

A. DucKnAm. .Pheenix Wharf, West Ferry Road, Millwall, 19th July, 1907.

A Motor "Growler" Wanted.

The Editor, "THE CommERemt, MOTOR."

Sir :—I see, in your last issue, that Mr. A. E. A. M. Turner returns to the charge in attacking the proposal to introduce a four-seated motorcab, and refers again to my letters which have appearedin your columns.

Mr. Turner says " the idea of hiring a hansom cab to take the air in the park with seems ludicrous," Probably Mr. Turner invariably rides in buses. If, however, he would take an opportunity of riding in a hansom, he would realise that it is one of the most airy vehicles that has been designed up to the present. The practice of hiring these and other horse cabs for short, recreation journeys has been a matter of common practice for years. I agree with Mr. Turner that 1' may be judging others by my own standard—it is a high one if the four-seated motorcab is not at present known in London traffic, how, may I ask, can anyone give a figure for its consumption of petrol? Mr. Turner says he obtained it from one of the

largest motorcab owners in London. How many fourseated motorcabs (carrying luggage) does this owner possess, that he makes such an authoritative statement as eight to ten miles to the gallon of petrol during its average day's work? Nothing but actual experience on the road will show anybody anything in regard to the costs of maintaining any motor vehicle. I think, therefore, that until such experi

ence on the road has been obtained with a cab chassis cap

* able of doing the work suggested, viz., replacing the old horse " growler," Mr. Turner will be better advised not to attack a suggestion, now backed up by the opinion of one of London's largest cab companies, for a capacious and comfortable motorcab to meet the larger requirements of the travelling public. Whilst a two-seated cab will certainly, for many years, hold undoubted sway in the realms of the short excursion in and round the Metropolis, surely something of a still more commercial type will be welcomed by everyone. By all means let us give every encouragement to designers and operating companies to produce such a vehicle at the earliest possible moment. Should it be a failure from the point of view of the shareholder, I shall admit that I have made a great mistake, but I feel that such a regrettable termination to the venture is one which

is very remote.—Yours faithfully, " LEGAL."

EAs this correspondence has assumed a somewhat personal character, it is now closed. The announcement lees page 500) that the Rover Motorcab Company intends to plane on the streets a vehicle of the type sugge.ted in the first letter of our correspondent, " Legal," would seem to bear out his contention 'that the four-seated cab is to become a feature of motorcab develop ments in the Metropolis. –F.D.]

Wagons or Tractors for Australia.

The Editor; " THE COMMERCIAL MOTOR."

Sir :—I have read with interest the letter on this subject from Mr. W. J. Law, and as an admirer of " TuE COMMERCIAL MOTOR," I am pleased to note how it gets about in the Colonies as well as at home. My object, however, in writing is not to compliment you, but to assist your correspondent if I can do so. As it happens, I have had some years' experience of both steam and motor wagons and steam tractors, and also I have had experience With the tangent wheels to which Mr. Law refers. Further, I have had experience with motor vehicles in one of our Colonies, though not in Australia. I know the latter Colony only by repute, but I gather that the conditions are very similar to those holding in some parts of South Africa.

Undoubtedly, for Colonial use, where the loads to be dealt with are fairly heavy, internal-combustion motors are not so suitable as steam vehicles, and, of the steam vehicles, the wagons are generally not so satisfactory as tractors. If I were to go into the reasons for the conclusions I have arrived at, I should probablyhave to fill a page of your journal, which I fear you would grudge me ; therefore, I will content myself with pointing. out that, in the case of steam vehicles, it is easier to get a larger firebox and greater heating surface with a tractor than it is with a steam wagon, where the boiler is small and the space allotted to it restricted, and, as colonial coal or other fuel is seldom so goad as the coal in England, this is a consideration.

One of the principal objections to the use of tractors, where the roads are hard and bumpy, has•been the excessive vibration. When the steel wheels, the almost universal practice, are used, this frequently results in the loosening of the rivets, the wheels themselves, and of the strope plates, and

looseness of several parts of the engine and boiler. Another objection to the use of tractors has been that, owing to their comparatively light weight, in conjunction with the fairly heavy load they are hauling, the wheels are inclined to spin and skid when the roads are greasy. In my own experience both these objections are removed by the use of these tangent wheels, and I must say that, though I was a bit sceptical at first of such a radical departure from ordinary wheel construction, I have been very pleased with the result so far. I cannot say exactly why, but there seems to be more " life " in the wheel, and the special tread which the makers supply for tractors certainly seems to substantiate their claim that it is non-slipping. Of course, it wears out in time, but, though I have not yet had occasion to do so, I understand that it can be renewed.

For colonial work, there is one great advantage which a tractor has over a steam wagon ; it is that it is independent of its load, and should it get into a tight place, it can drop its load, extricate itself, and then by means of the wire rope and winding drum, haul its load out afterwards. In the case of a steam wagon, or other vehicle carrying its load on its own back, it would be necessary to remove the load before the vehicle could extricate itself, and even then, owing to the smaller diameter of the wheels, it would not do so with the same facility. I will not attempt to answer the questions which your correspondent asks, as no doubt you will be replying to these yourselves, or probably the makers concerned will do so.—Yours faithfully, " E XPERIENTIA."

Vibration Effects : a Suggestion.

The Editor, " Tux ColatExcIAL MOTOR."

Sir :--The recent correspondence in your columns re the bad state of the Hammersmith-Mortlake road, which is used by the vehicles of the London General Omnibus Company, has been a reason for my making a few general inquiries as to what is the result of excessive vibration. I hear that, among other troubles which beset the engineers, that tubes frequently give way at a point where they are brazed into the unions. Now, it appears to me that this specific annoyance might be got over by making the apertures in the brackets, etc., that carry the different pipes, of a relatively large diameter, and placing in these said apertures a thick rubber washer having a central bore through which the tube could be passed. The above method would ensure the necessary cushioning effect to prevent fracture of any joints, and, at the same time, would do away with much of the noise when the vehicle is running.—Yours faithfully, D. MORTON. Ipswich, 20th July, 1907.

Road Locomotion and Public Health.

The Editor, "Tim COMMERCIAL MOTOR."

Sir :—In the extracts from Dr. Hele-Shaw's address to the Royal Institute of Public Health Congress on " Road Locomotion in Relation to Public Health," to which you give publicity in your valuable issues of July nth and 18th, we notice that Dr. Hele-Shaw—in common with most people who have given any degree of attention to the subject of road traffic—lays special stress on the problem of " dust raising." We quite agree with Dr. Hele-Shaw when he says that he has strong reasons for believing that some substitute for the ordinary wheel will be discovered and come into use before long. We believe that, of necessity, this will take the form of an alteration in the existing pattern of ring tire, rather than that of a modification of the wheel proper. To our minds, the question of " dust raising " is to a very large extent—much larger than is generally supposed—more a question of tires than of body-building. A great part of the dust raised by all classes of vehicles is undoubtedly due to the fact that the ring tire of to-day does not absolutely grip the ground in its revolution, but actually revolves at a greater rate than it travels forward, this having a scooping action on the ground, which results in its projecting dust and mud horizontally to its rear. If the distance covered in the revolution of a wheel were exactly the same number of feet and inches as the actual circumference of the wheel, we think it would be agreed that a great portion of the present dust raising would be avoided.

In the " K.T." tire, which we are just putting on the market as the result of two years' extensive experimenting, we claim that this result is obtained, and that all the pow er put forward by the engine is utilised in covering the actual distance, and not—as in the present ring tires—partly in friction between the road surface and the tire, and partly in forward movement. Owing to the shape of the studs on the tire, and the fact that they are pneumatic, we claim that they possess a grip on the road surface, combined with resiliency, that is equivalent to between rz and 17 per cent. in-. crease in efficiency over the present-day pneumatic tire. It will, therefore, be seen at a glance that this ratio will be much exceeded in the case of a solid tire. We claim further, that our " K.T." tire is the only pneumatic tire on the market which has successfully been applied to the carrying of great weights, and, as evidence of this, we may say, that we have been for some months carrying a to-ton back-axle weight on these " K.T." pneumatic tires, in Belgium. We take the liberty of addressing you thus, as we feel sure that, in view of Dr. Hele-Shaw's remarks, these facts will be of interest to the general body of your readers,—

Yours faithfully, THE " K.T." SYNDICATE, LTD.

Tags

Organisations: Congress, Royal Institute
Locations: London

comments powered by Disqus