WHAT HAULIERS ARE TALKING ABOUT. _
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Difficulties and Problems that Come Up for Discussion.
AGATHERING of hauliers is always interesting-company, but., for some reason or ether, when they assemble outside business hours, they always succumb to the tendency to talk " shop." One does not, complain, because their experiences are always So interesting, and-so strangely reminiscent as to echo an interest even in the ear of the person who is not one of them.
The merits of benzole, as compared with petrol,, for the motive power of commercial ears do not appeal to hauliers. The use of benzole is a questionable economy, and I have repeatedly heard hauliers complain of the overhauling necessary owing to the accumulation of a glutinous residue. The owner of a big fleet recently stated at a, meeting, "Whenever a canvasser for benzole calls upon me I always ask, 'Can you guarantee, it to be free from sulphur or sulphuric acid? ' And no one has been forthcoming with assurances.'' Another point of common interest is the allowance which should be made for interest on capital ad depreciation. Many of those who are newcomers to the road transport industry very frequentlyneglect to make a proper allowance to cover these items, with the result, if the opinionsof " old stagers" be any criterion' that some of them will find that, the profits they had been hoping for, if they ever existed, have vanished. I recently heard a haulage Contractor, of several years' standing, say that depreciation and interest on capital were his heaviest items of expenditure. The proportion of depreciation can be divided into four categories as follow:—(1) Depreciation resulting from wear and tear ; (2) depreciation,resulting from age ; (3) depreciation due to inadequacy ; and (4) depreciation due to obsolescence.
O.H.J.
. MOTOR COACH NOMENCLATURE.
Names that are Apt, and Names that are Inane. AN 'INCREASING tendency has been noted of late towards apr ending a distinotiare nomenclature to motor coaches. Railway engines and craft that sail the seas are distinguished by a , name, so why not the pa.seenger vehicle ? There are so many christened "Pride of the Road" that, a short time ago, even Mr. Punch paid them a passing -tribute. In the Blackpool district there have been noticed several " Queens of the North,", but never a "King of the North." Ona recent motor coach tour in that neighbourhood, a broad grin illuminated the countenances,of the passengers when " Smile-a-while " passed them on the road. Many cars there are designated the "Victory," but only one "Happy Valley "'have we seen. The " Marathon " is also uncommon. Of course .the majority of coaches " sail along" under the " fleet " name, but we would suggest. that, as names usually have a psychological influence on intending passengers, they be chosen with greater discrimination, free from flippancy, topical allusion, hackneyism, and any suggestion of localism, and aiming rather by an easily remembered word or phrase to establish the identity of One particular vehicle or fleet of the thousands on the road. The "Royal Blue" fleet, radiating from Bournemouth, provides a happy example of a name well chosen for descrip c12 . tiveness and dignity. One can hardly imagine a prominent men, with a reputation for solidity, being favourably disposed towards the idea -of passing through a district where he is well-known in a vehicle bearing the flippant and glaring name of 110WARUE. • A name should be happy yet not commonplace, and if it can' reflect some one aspect of the coaches—as'• celerity, comfort, etc., so much the better, but, above all things, a, name, if 'it is to have an advertising value, must be coined to insinuate its way into the memory. Maybe, the Commercial Motor Users Association could keep a register of motor coach nomenclature. S.F. G.
WHY CAST STEEL WHEELS CRACK" fensional Strains Set Up in Cooling after Casting .
IN THE PAST much trouble has been experienced owing to the tendency for steel wheels to crack at certain points. These points occur particularly where the spokes enter the. rim, and where they emerge from the wheel hub, though mat' so often in the latter position as in the former. Experiments have been _conducted with many shapes of spokes, and, at one time, the cracking was thouglit to be due to the rim being flexible enough to rock on the spokes, using the latter as fulcrums. The real reason proved to be the sudden diminution in bulk of the metal between the rim and the spokes, with the result that, immediately after casting, the spokes, with their small bulk of metal, solidified, whilst the rim, with its comparatively large mass, took much longer to solidify, with the result that tension was created in the neighbourhood of the spoke ends, and, if cracks did not appear on the surface, they were present in the interior' or, -at least, the tendency to crack was there. Lately, it has become the practice.to increase the mass of the spokes, particularly where they enter the rim, so that the changes in mass are not so abrupt and, thus, the solidification of the material takes place more regularly throughout the structure.; S.T.R.
CENTRIFUGAL FORCE ON LUBRICATING OIL.
The Initial Pressure on the Oil Need Not be Great. FEW PEOPLE realize that, even in, an engine in which the whole oil supply is not pressure fed, there is still considerable pressure on the oil which lubricates the 'big-ends if the crankshaft be drilied so that the oil can enter it. Why this should be so can be seen easily when we consider what happens to the column of oil between the centre of the eranksheit and the big-end journal. Taking an engine with a e in. stroke, the throw of theecrank will be 3 IAS., and the centrifugal force may be taken as acting oa the centre of gravity of a coPumn of oil 3 ins. long. At an engine speed of 1,000 ap.m., and with oil at a density of 0.9, this centrifugal force is equivalent to an oil pressure of approximately se lb. per sq. in. If the engine has pressure-fed oil through a drilled crankshaft, the actual Pressure at the big-end bearings will be the gauge pressure of the oil plus the centrifugal force acting on-it. It will therefore be readily understood why, except in the case of very high-speed engines, where the bearing pressures are enormous and the tendency to squeeze out or break through the oil film is great, the pressure on the lubricating oil need not be more than a few pounds per sq. in. J.M.G.