HINTS FOR HAULIERS.
Page 15
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The Value of a Little Extra Engine Power in Saving Time and Reducing Running Costs
IWAS very interested, when reading in last week's issue of The Commercial Motor about the Daimler Hire Service, to note that the company, which at one time favoured the 30 h.p. ear, is now changing over gradually to the 45 h.p.. There is no reason given in the article to account for the change, and, personally, I have no direct knowledge of it, but I think I can get sOrnewhere near it. Strangely enough, it is just this very question of engine size in relation to the load which has been exercising my mind lately, particularly with regard to hauliers' requirements, and this leaning, on the part of an important company, towards higher power confirms the conclusion which I had independently reached—that it is a mistake to limit the engine power.
An important and essential feature of the haulier's service is Speed of operation. Now, speed is limited legally, and by traffic and hills. The legal limit applies in various ways, as in " 10-mile " areas, and here, there, and anywhere where the police or the authorities have a fancy for interfering, logically or otherwise, with the motorist. Additionally, of course, there is that proper limitation of speed according to the condition of the road surface, and with due regard to the safety of others upon the highway. These conditions, however, affect only the maximum speed of the vehicle, attainable only, apart from these more or less right and proper restrictions, on the level roads'. On such roads but little power is needed, so that. the question of engine size does not then arise.
Where Time Can Be Saved.
The most important speed restriction is that set by the nature of the country; by the necessity to climb hills which, if power be lacking, must be tackled on some of the lower gears. For hill-climbing at speed, engine power is required. A vehicle which is fast on hills may save a day a week as compared with one which is not. Additionally., .another valuable aaset of the high-powered chassis is rapid acceleration after a stop, as in traffic. It is the high-powered machine which heads the procession, in a few yards, after the policeman has lowered hi st arm.
A little concrete example may help.
Suppose a, vehicle is setting out on a journey, in hilly country, of 100 miles. Let us assume that 60 miles is over level, good roads or down gradients. Its speed for-that 60 miles may be, say, 20 miles per i hour. For the rest of the journey t is hill-climbing. If the engine be small, a lot of low-gear work may . be done. Perhaps 20 miles will be done at 12 m.p.h., 10 miles at 10 m.p.h., and the remainder at 4 m.p.h. The total time for the journey is:-Three hours for the fast stretch, 1 hr. 40 mins. at 12 m.p.h., 1 hr. at 10 m.p.h., and 2i hrs. at 4 m.p.h. ; total time, 8 Era. 10 mins. . .
Now, another vehicle, with a more powerful engine, might easily keep a gear higher than the other, so that, without reckoning on any iiicrease in speed on the level, which means that the 60 miles, would still be run in three hours, he would do the .20 miles of easy gradient on top gear, also at 20 .miles per hour, the next 10 miles at 12 m.p.h. (50 min.), and the balance at 10 m.pii. (another hour); total time, 5 hrs. 50 mins. As a matter of fact, his bigger engine would most likely enable him, by allowing better accelera. tin, to gain a further 10 Minutes or so, reducing the time to 5 hrs. 40 mins. ; a saving, as against the other
machine, of 21 hours!. Easily enough to enable an extra journey a week to be made. The importance of a saving of time such as that exemplified need hardly be laboured. From the haulier's point of view, one particular aspect need only be indicated. His hours are not necessarily limited to eight per day, but his times for collection and delivery generally are such that, unless he can load up, complete a journey, and unload, or at least commence to unload, within nine or ten hours, he is sure to have to waste a lot of time at journeys' ends In the case selected for disdussion, it is more than likely that to take 8 hrE, 10 mins. for the journey will mean that he must either load up overnight, ready. for a prompt start in the morning, so as to be able to unload the same day at his destination, or, if he can only load on the morning when he carries out the run, be will have to stay the night At the other end; and unlead next morning.
With a powerful engine, taking but 5 hrS. 40 mins. on the road; it is quite likely that he will be able to complete the whole job in one day.
Where the Coach Owner Will Benefit.
To the motor coach owner the saving of time is still more important. His passengers, although interested to a certain extent in the panorama of nature and all that sort of thing which is being unfolded before their eyes, " and all that" (vide advertisements), are, nevertheless, anxious to get to their journey's end. Even if they are not—even if it be the journey they want (" Commence your holidays at your own door ") —they certainly do. not welcome slow, bottom-par grinds up hills, and it is as easy to see and appreciate scenery at 30 miles per hour as at 15. If a powerful engine be wanted in a hire car, it is wanted more in a. haulier's wagon, and more Still in a motor, coach. Indeed, my prophecy with regard ,te the latter is that only the man who owns six-cylinder, high-powered, prieurnatie-tyred vehicles will be in the business in a few years' time. Certainly he will be the only one doing long-distance work.
. Keep on the High Gears-.
. Lack of power in the engine makes itself felt with cumulative effect in hilly country, chiefly because ot the frequent gear changes necessary, for .se soon as top gear has to be relinquished for second or third, as the ease may he, 10 per cent: of the engine power is immediately thrown away. For example, an engine which develops ao h.p. transmits 90-per cent, of it, or 27 h.p., to the road wheels, on direct gear: So soon as any indirect gear is engaged, a further 10 per eent drop is experienced, and the power available atthe ioa.d.wheels is then but 24 h.p. On a -hill,. therefore, which bAiis for a change down on a 30' h.p. engine, the power available is but 24, While, with a 40 h.p. 'engine, assuming no change of gear is needed, 36 h.p. is there All the time.
Then, again; considering the matter from another ' viewpoint, a 40 h.p. engine will have transmission to suit, and as its full power is used only on hills, that transmission is, on the whole, but gently used, and lasts longer accordingly: A 30 h.p. engine calls for full service from its lighter transmission, and, in addition; subjects it to the rougher treatment which is inseparable from gear-changing. THE SKOTCH.