OPINIONS
Page 54
Page 55
If you've noticed an error in this article please click here to report it so we can fix it.
and
QUERIES
POLICEMEN WHO MAKE CASES.
[5306] I would like to draw your attention to a case that I had last week. I was driving a lorry through our district and was approaching a crossing controlled by a policeman. In my opinion he waved me on, but when I was half-way across he stopped me and asked if I had read the Highway Code.
I told him that it was his mistake, and he ,called me a liar. I then said that I would report him, and he replied that if I had been on my own he would have sworn in court that he had not called me this. He also said that his word would be law.
Fortunately I had a man with me and the constable was glad to let the matter drop, but had I been on my own I would not have stood a chance, as magistrates believe the policeman every time. That is where the administration of the law is often wrong.
Manchester. J. S. GARSIDE.
MERGERS AND SALES.
[5307] I have read with interest the comments on the question of the sale of haulage businesses in both The Commercial Motor and contemporary trade journals, and my feelings are, briefly stated :—
(1) Rationalization is necessary and bound to come.
(2) Unity (properly conceived) is essential, as giving strength (plus "powder and shot ") to fight the railway companies, etc., and to meet the future.
(3) In any proposition constructed on sound businesslike lines the individual owner or concern will reap the reward earned, and most (if not all) the objections so far raised will be met and overcome.
(4) The future is problematical.
(5) Schemes on the basis so widely reported in the trade Press are doomed to failure in any event—from the point of view of the individual concern.
With several of the leading concerns in the industry a definite and. forthright business-like scheme has been evolved, in conjunction with a certain issuing house, and this scheme will ensure to those concerned a full return for their past labours and enterprise.
We are not writing for a " to-morrow "; we know our own minds and are prepared to avail ourselves of the advice of our own professional advisers in dealing with our affairs in a private merger.
Marston Green. ALFRED E. P. ROBERTS.
BUS-FARE COUPONS.
[5308] Greatest nuisance for bus conductors during the rush hours is giving change. Many passengers take the trouble to have ready the exact fare, and that, 12 times a week, is a nuisance to them. Here is a method of saving the conductor's time which would be a convenience to the public.
Let the companies issue books of vouchers for fare tickets, in denominations of all values required, in booklets of 12, or in greater numbers if desired, avail 1340 able any time on any route. A voucher would be exchanged for a ticket punched for the appropriate fare stage according to the value of the voucher.
As in 75 per cent, of the rush-hour traffic passengers make the same journey daily, ticket vouchers, obtainable once a week, would be less troublesome than tendering 12 fares, whether with the exact money, which is bothersome for the passenger, or receiving change for the coin tendered, which is troublesome to the conductor. " TWICE DAILY." London, W.C.1.
ENGINEERING FILMS REQUIRED.
15309] I am compiling a list of 16 mm. films available for showing to engineering societies and similar bodies, and should appreciate your allowing me the use of your correspondence columns to facilitate my task.
I should be very glad to hear from companies which have films of this size dealing with any technical aspect of their businesses in order that I can add their names to my list and, at a later date, make arrangements to include their films in the programmes which form part of our winter lecture sessions.
The Society's membership is drawn from most branches of the profession, from well boring to aeronautics, and there are few technical subjects which would not be of interest.
We have an up-to-date projector and normally arrange our own showing, unless the firm concerned wish to send their own representative.
J. B. HEWITSON, Hon. Secretary, Reading and District Engineering Society. 5, Chalgrove Way, Emmer Green, Reading.
WHY NOT USE NO-TURN BOLTS?
153101 I would like to bring to the notice of vehicle and body manufacturers the desirability of using "no-turn" bolts. There are so many places where it is difficult to hold the head of an ordinary bolt when it is necessary to tighten or loosen the nut, and "no-turn" bolts could be used for such parts as petroltank brackets, springs, battery brackets, flywheel housings, cross-members, etc.
An electric welder can make sufficient of such bolts in an hour to supply two or three vehicles, and the extra weight would be negligible.
Mechanics already have quite enough of the " octupus " stuff, and anything that helps them to do the work with just two hands would be appreciated.
Let us also have better accessibility. This is far more important than streamlining, although this may be desirable, but not to the extent of unduly hiding parts and rendering them almost non-reachable.
It is hardly necessary for me to describe what I refer to as the non-turn bolt, because this is as old as the hills. Some used for coachwork have a little nipple under the head, but this is not always satisfactory because the nipple is usually so small, but where a bolt head is close to another part it can easily be prevented from turning by welding to one of its sides an ordinary
square nut. G. H. STADE. Victoria, B.C.
A DIFFICULT STEERING PROBLEM.
[5311] Would you please help me with a query about which I have found myself greatly puzzled. I have searched several-text books for an answer, but all my efforts have been in vain.
The problem is this :—Assuming that I have a lorry with overall dimensions of 9 ft. width and 14 ft. length, with the usual steering on the Ackerman principle, and _ that it can turn (on full lock) a circle of 45-ft. diameter. Is it possible to determine, Mathematically or geometrically, the minimum width of road; incorpora ting a right-angle turn, along which the vehicle can travel without having to reverse, or use any other method than direct steering to turn the corner.
I would explain that the dimensions stated are merely assumptive, the whole point of the problem is whether it be possible, on paper, to determine the minimum width of road along which a vehicle of known dimensions may travel and turn a right-angle corner.
I was faced with this problem early in 1937 whilst stationed in Egypt and employed as a draughtsman with my corps. It was when building operations were being carried out inside the R.A.S.C. workshops.
After making many unnecessary and ineffectual calculations on paper, I solved the problem by taking into the desert the largest vehicle with which we had to contend, and obtaining the necessary data from the tracks in the sand.
This question, by the way, is not an official inquiry, but just a problem which has intrigued me all the more because I have been unable to find anyone amongst my colleagues who could answer it.
I wish The Commercial Motor continued success.
Colchester. A. M. JONES, SGT., R.A.S.C.
[You raise a very interesting little problem and we have worked this out for you on the accompanying diagram, from which we hope you will be able to understand the solution_ For simplicity we have taken dimensions somewhat different from those you quote and, instead of width and length of vehicle, have worked to wheelbase and track, which obviously are necessary when dealing with the positions of the wheels. If your right-angle corner is bounded by walls more than a foot or so high, you will, of course, have to add a little for the overall figures in order to allow clearance at the sides and ends of the body. You can easily do this on the drawing and modify the
boundaries of the road accordingly. In making the diagram, the first thing to do is to describe 90 degrees of the turning circle, which has a known radius: we have taken 24 ft. At any point on this arc draw, at a tangent to it, one of the front wheels. From its centre describe a second arc, having for its radius the wheelbase, which we have taken as 11 ft. Then from the original centre draw a radius which forms a tangent to the second arc. At the point of contact you can draw in the outer rear wheel of the vehicle which, of course, will be at right angles to the radius. From these two points, knowing the track (7 (t.), you can easily find the positions of the other two wheels, noting that the inner front wheel is at right angles to the radius from the main centre. Having done this, draw the outer boundaries of the road, one of which must be parallel with the outer front wheel and the other at right angles to it tangential to the turning circle. Then bisect the angle formed by these two boundaries and: where the line cuts the innermost circle. which you can draw from the position of the inner rear Wheel, draw the inner corner of the road. Having drawn this diagram accurately.. you can find by measurement the width of the road, which is found to be approximately 14 ft. for the dimensions we have used. You can calculate the desired dimension from the known dimensions by adapting the Pythagoras theorem. You will probably be able to follow it from the workings on the attached sheet. Following thediagram, as you know the figures for AB and CA, you can get BC and, from it, CF. CF is a radius of the inner circle and, therefore, equals CE, which is the hypothenuse of the isosceles right-angled triangle DEC; so CD is EC divided by 4/ 2. That is all the information you require, because, by subtracting DC from the turn ing radius, you get the width of the road.. When you try and trace the course of the vehicle coming into the bend, you find yourself faced with a confusing issue, because, as you know, a vehicle can turn in reverse into a narrower space than it can when travelling forwards. Accordingly, for uni-directional travel you could reduce the width of the leading branch of the corner, but as, presumably, your vehicle will be negotiating the turning in both directions, it is necessary for the two branches to be of the same width. We hope this will clear up your difficulty. Thank you for your good wishes to The Commercial Motor.—ED.] [5312] I should like to thank you for the very kind interest you have shown in my problem, and to compliment you on the most lucid manner in which you have explained all points. On going through your solution, I found it most simple to grasp the points of the problem which had, hitherto, evaded me.
I should also like to say that I have been a constant reader of The Commercial Motor for many years and, as a fitter in the Royal Army Service Corps, have always found the journal both instructive and interesting.
A. M. JONES, SGT., R.A.S.C. LICENSING VEHICLES FOR ROAD-MAKING.
1.53131 I am at present running six tipping -lorries, four under A licences, one C and one Contract A. I have three working on the highways for a council.
I was at a C.M.U.A. meeting the other night and a friend of mine told me that I did not require A, B or C licences so long as I was working for the council on
the improvement of roads. W. HANCOCK. Bold.
[We are afraid that you have been misinformed by your friend when he said that you did not require a carrier's • licence when working for a council on roadmaking work. It is only where the contractor to a local authority supplies vehicles for road cleaning, watering, refuse collection, cesspool emptying, or in connection with the enactments relating to weights and measures, or the sale of foods and drugs. that a carrier's licence is not necessary.--En.]