Answers to Queries.
Page 20
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Tests of Lubricating Oils.
1211:5j (Glasgow).We have no department which undertakes the examination of lubricating oils. You might be able to get work of the kind undertaken by Mr. G. W. Watson, 83, Pall Mall, S.W., at a reasonable fee.
Milk by Petrol Van.
[2446] (Dairyman).—You can rely upon the absence of contamination of the milk by any smell. from the petrol. We have never heard of a complaint of the kind with any substance in it, although we have read in the general daily papers that fears in that direction were at one time entertained.
Commercial Tricars.
[2117] (Manchester).—Amongst the names of makers of three-wheeled pareelears are: Auto-Carriers, Ltd., Ferry Works, Thames Ditton ; Girling Commercial Cars, Ltd., Bedford ; John Warrick and Sons, Ltd., Reading ; A. W. Wall, Ltd., Roc Motor Works, Hay Mills, Birmingham ; Phanomobiles, Ltd., 328 Upper Street, London, N.
Tire Sections for Six-ton Fire-.engine.
[2448] (India).--We are unable to say who is to blame for the specification and fitting of tires of so small a section as 90 mm. upon the rear wheels of the fire-engines in your department, but we agree with you that they should be larger in section. The vehicles are, in our opinion, under-tired, and it would undoubtedly have been wiser to have had 120 mm. twins. Possibly the under-tiring was due to close cutting in the tender. We note that each engine weighs six tons gross.
Mr. Geo. Watson's Spring Chart.
[2449j (Leaves).—We see no reason whatever to alter the formula, or to make any correction of the chart. Your trouble appears to arise from one of two causes: either you do not know the load you are putting on, or the spring is so stiff that it sets up excessive vibration, and the vibration itself leads to the early failure of the spring. We have often found that spring makers who insist on putting in a large number of leaves generally do so because their springs are made of poor ntaterial. If you have springs made with 11 leaves, in accordance with the formula for your case, and made of good material, such as those supplied by Jonas Woodhead, Andrews and Go., Cary, or other good maker, you should have no failures.
The Pleasure-car Trouble.
I-2-1301 (Bread and Groceries).—The car, or any other pleasure car, is likely to give some trouble when used fo.. loads as high as those which you mention. In reducing the number of teeth on the sprocket from 16 to 12, you will, of course, not improve the life of the chains. Your fuel, oil, tires and repairs are not excessive if they together come out at not more than 4d. per mile run, having regard to the use of pneumatics on the front wheels. We cannot account for the quick wear of the big-ends, provided the supply of oil is never allowed to get low or to fail. This excessive wear may, of course, be due to the crankshaft's being slightly out of line ; that is a point which you could not check yourself, although you might ask the local repairer to look into it next time a repair to the big-ends is being effected. Of course, if any of the oil-holes are choked, thus preventing oil having access to the big-end bearings, or if the dippers on the under side of the big-ends are bent or broken, that might account for the difficulty. Have you any means for giving an auxiliary supply of oil by hand? If so, are the pipes leading this auxiliary supply in proper order, and have you ever checked whether they c14 deliver the stream of oil where it is needed ? It is, of course, important to make up the oil in the crank chamber daily, if there is any leakage, rather than to put in a larger supply say twice a week. The consumption which you mention. (two gallons) is veryhigh for 190 miles of running ; you ought to use one gallon at the most, except for losses by leakage. We think you will not get anybody to sell you a oneton chassis, for that is what you evidently require, for so small a deposit as £25 and the old car. Heavyvehicle manufacturers do not like to collect old cars. You might have a chance of picking up some secondhand commercial chassis.
What Rates Will Pay?
[2151] (Contractor).—We have posted to you direct a copy of our free sheet of running costs. You should try to get double the revenue per mile which is shown on this sheet, when working as ,a contractor, seeing that you have certain contingencies to meet, and that the work must bear all the charges itself. A 60 per cent increase is essential to a profit margin. When owners carry their own loads for their own purposes they do not charge anything for management or supervision. Further, you have, to guard against the risk of delay at the loading points, which matter is better under the control of an owner who has his own vehicles, whilst you have additionally to provide a spare vehicle to prevent interference with continuity in the event of any breakdown.
Charges when no Return Load.
[2452] (Cheaper).—The wagon in question (Answer No. 2422) is a five-ton steamer, and it is sometimes used with a trailer, as the answer shows. The mileage revenue refers to both light and loaded running reckoned together, and not merely to the mileage when under load. In the case which you refer to
us, from to Southampton, it would be the mileage for the double journey. Of course, in reference to a threetonner' limping without a trailer, the comparable figure, instead of either is. 3d. per mile Or Is. 6d. per mile, because it has to yield a satisfactory profit for a contractor, would in our opinion be a minimum of is. per mile run. If you are in business as haulage contractors and have to charge the whole expense of your working against your revenue from carrying, the figures which we have given are paying ones, and anything lower makes in the direction of loss or even bankruptcy. If. on the other hand, there are other departments against which part of the management and other expenses can be charged, lower rates can be accepted with impunity. We do not find it any advantage, to recommend carriers to accept unduly cut prices ; it really pays them better to keep their vehicles in their depots. I