The Petrol Trail

New Zealand Times, Volume LII, Issue 12163, 13 June 1925, Page 18

The Petrol Trail

ROAD CONDrriONS IN AND NEAR CITY The advent of' the 'Highways Board is looked upon as a step in the right direction, and that' the time is approaching when the arterial roads in the Dominion will be - highways n reality and nqt merely in name. The tax that has been collected reached an appreciable amount, and if the money is expended to the best advantage, motoripg will become a pleasure instead of a trial. ' During the past year- the streets of the city have received attention, and some of the surface of some of the main thoroughfares has been made as perfect as possible, THORNDON QUAY ; This street was continually in a bad state, although much money was expended on upkeep, but is now in splendid order. ,This being a main artery, it is called upon to carry heavy traffic and so far the surface hae proved equal to requirements. In addition to heavily-loaded wagons of merchandise, which pass over it daily, carrying supplies to the towns in the Hutt Valley, Wairarapa, Manawatu, and districts en route, there is a bus service in competition with the railway. These vehicles are almost continuously on the road, and would soon damage an in-differently-constructed surface. GHUZNfeE STREET The upper portion of Ghuznee street carries a big volume of heavy. traffic. It has been in .an exceptionally bad condition for many months Wate» had worn channels in the surface in many places, which, together with,potholes, were responsible for the breaking of motor-car springs! The road has now been repaired, and is in firstclaes order. Probably when the council is in a position to tar seal this portion it will do so, as the present macadam formation will not stand up to the traffic. WILLIS STREET Frolh Manners street intersection to Aro street this artery is fast becoming a, thoroughfare to be avoided when possible. Ruts and holes abpund, and ait the tram stop above Dixon street there are several cavities which one might expect to find in' a back country road but never in a city. In wet weather these holes become filled with water, and passing motor-cars send the muddy liquid across the footpath, giving pedestrians who may be in the vicinity a liberal sprinkling: 1 The work necessary to improve the conditions should be undertaken without undue delay. TARANAKI STREET Excellent work has been accomplished in the lower portion of this street. It was in a shocking state before the council took it in hand, and to-day it is a credit to the city and those responsible for its reconstruction. CLYDE QUAY The surface of this thoroughfare should receive attention. It is recognised thri* the city authorities cannot accomplish impossibilities with the plant at their command, but the drive along the waterfront is one of Wellington’s main attractions, and the present state of the road is a disgrace. Oriental Bay is in a similar condition. EVANS BAY Compared with a few years ago. the road in Evans Bay has been improved to an extent that it is nc#i recognisable. It has been widened, and the sqp wall, ■ when completed, and the road tar-sealed its full length, will give the citv one of the finest drives in the Dominion. AT PETONE, The portion of the road between the railway crossing and White’s Line has never been satisfactory. The Petone Council has spent a . considerable amount on it, but apparently the foundation is not good, as its lasting quality is of very short duration. A great improvement has, however, been made along the esplanade, and motorists are looking forward to the time when a tar-sealed road will be an accomplished fact from the city to Eastbourne. MOUNT STREET CORNER This is probably one of the most dangerous comers in the city, and extreme care should bo exercised in negotiating it. When inquiries wero made, tome months ago. the corporation authorities stated that the work of widening the annroaeh was t,o he undertaken immediately Nothing, ! however, has been accomplished, and ' all meet Idailv reports of narrowlyaverted accidents come to hand, TINAKORI ROAD Described by motorists as one of the best liver-shakers in Wellington. i

WHERE FUEL IS WANTED HEAT AND FRICTION LOSSES. • 1/. ' ““ " In any mechanism’ which is designed for the purpose of converting one form of energy int'6 another losses are bound to occur, andc.the motor-car chassis -is no exception to this general rule. A study of the ways in which these losses occur and their relative magnitudes possesses considerable interest in itself, and also shows clearly to which components ‘ attention might be directed, with the object of minimising some of the wastage. The engine is the worst offender, as may be gauged from the fact that, when it is delivering, say, 20 h.p. at the clutch, the energy possessed by the fuel' which is being consumed actually represents 80 h.p. or more. In other words, three-quarters of the fuel entering the carburettor is wasted in the engine alone. . When other losses,, present in the transmission, are con-

sidered. it is found that the theoretical miles per gallon, wastage neglected, amount. to nearly five- times the aotual m.p.g. accomplished. MOTOR-CAR v. LOCOMpTIVE These figures are rather startling particularly when it is pointed out th.it they refei to a. car running under really good conditions and the mechanism of which is in a high state of efficiency. To get an idea of how the car compares with other machines used for locomotion, it may be mentioned the railway engine only uses about onetwentieth of the energy present in the coal which i 3 consumed. Hence, by comparison, ■ the motor-car makes an extremely good showing: but still better results might be obtained if the sources of loss were tackled one by one and the efficiency improved so far as possible. As figures ' are always more acceptable than,- tehoretical symbols, for the purpose of demonstration take the case ,of a car weighing about one ton, proceeding along the level at its maximum speed of 50 m.p.h. The easiest way of tackling the subject is, first, to consider the resistances which are being overcome, and, secondly, to examine the power lost in overcoming them, starting from the rear wheels and worldug forward.

, Two kinds of resistance are met with, namely, thd rolling resistance made up of the friction of . the hub bearings; etc., and the wind resistance caused l>y the ; passage of the body through the air. Average figures for the car•fconsiderqd will be:; —7.h.p., expended in overcoming the rolling resistance, and 10 h.p. expended in forcing the car through the.air. -The pow<~. required :at the rear wheels is, therefore, the sum of-the two, or 17 h.p. Starting to examine the ; transmission, the causes of loss first met with are the gearing .and bearings employed in the final drive, r When transmitting 17 h.p. to the rear wheels, the loss will amount to approximately 21 h.p., so that we arrive at a result of 19J h.p., transmitted by, the propeller shaft. Going -a step farther, we come to 1 lie gear-box, and here, assuming ton gear is used, the direct drive will not absorb very much-power. However, the constant mesh wheels will be rotating at a high speed, churning the - lubricant, and there will be various bearings, the friction of which, will absorb a certain amount of power. Taking half a horse-power as an. average'figure, we find that .the power which must

be delivered to the clutch totals £0 h.p. ENGINE THE GREATEST WASTER We now arrive at the engine, and here it is that the greatest wastage of power occurs. First of all, then, are numerous mechanical losses, due to the friction. of the working parts and to the various necessary auxiliaries which must be driven, so that the energy produced at the clutch is considerably less than that evolved by the gases in expanding in the cylinders. Further, the mixture is drawn past the inlet valves bv suction, and, to a certain extent, the spent gases must, be forced out of tlic cylinders by the pistons. The energy absorbed in moving the gases in this way is generally referred to as the “pumping loss,” and in the case under consideration will amount to about half a horse-power. A greater loss will ccenr if. the valve timing is not suitable. As regards the frictional losses in the mechanism, that which is caused by the rubbing of the pistons against the cylinders is by far the most serious. This is due to the fact that, owing to the heated condition of the metal surfaoes in contact, it is very difficult to provide anything like adequate lubrication. 'Various ingenious designs of slipper piston have been brought out to minimise this difficulty, and. in addition, designers have adopted expedients, such as offsetting the cylinders, in order to reduce the load 1 on the rubbing surfaces. However, despite these efforts. in the case«pf an engine deliver, ing 20 h.p., the power lost in moving the pistons up and down may well amount to 2 h.p. The bearings are in a much better lubrication, because they are fed with relatively cool oil, and are lined with white metal. However, when one takes, the camshaft and- crankshaft bearings into account, and also the various bushes provided to carry the timing wheels, etc., the total loss may easily amount to half a horse-power.

VALVES, PUMPS, AND FAN^ The main amount «f power is, of course, used in actuating the valves, the water pump, and oil pump, and also in driving the fan. The fan, in particular, when running at a high, speed, absorbs considerably more power than one might at first anticipate. Electrical units are also shown, average figures for an engine of the size under consideration being given. It will be seen that, after taking into account pumping losses, mechanical losses, and the energy consumed by auxiliaries, a grand total of 5 h.p. is arrived at. This means, that the expanding gases in, the cylinders must actually produce 25 h.p. in order that 20 h.p. may be available at the clutch. One now comes to the losses which occur between the entry of petrol to the carburettor and the generation of power in the cylinders. Here there ore two main factors to contend with, these being the energy wasted in the exhaust, and the energy lost in the heat transferred to the cooling water. Large as these losses are, it is a fact that it. is almost impossible to reduce them without sacrificing something in other directions. Actually, as previously stated, our engine is consuming fuel equivalent to 80 h.p. and *s generating energy in | the cylinders at a rate of only 25 h.p.' The difference of 55 h.p. is mode up of a cooling loßs equal to about 20 h.p., and a loss 1 in the exhaust pipe equal to about 35 h.p. | Many attempts have been made to reduce the second “of these losses by making thc exhaust gases do further work after leaving thc cylinders. These have failed, mainly through complexity, and in some cases because the mechanism used imposed such a serious back-pressure on the pistons that the\ Bmall gain obtained was nullified by increased losses in the engine itself. COOLING LOSSES As regards cooling, this must, of course, be canned out in order to prevent the troubles which would naturally crop up if the cylinders and pistons woro allowed to overheat. The loss may, however, be reduced to a minimum by maintaining the engine at the bqst possible working temperature, which is, in. most cases, round about 180 degrees F. A step in this direction lias, of course, been made by many manufacturers, who fit thermostatic controls to the water circu-1 luting system. Here it may be worth mentioning I that ah ingenious scheme was suggest- 1 ed some time ago for minimising the exhaust less, and maintaining an equable temperature at one and the . same time. The" proposal consisted ot I using exhaust gases to drive a turbine, which was to be coupled to a fa-i, directing air on the finned cylinders. In this system the power necessary to. drive the fan was obtained from a source usually wasted. Furthermore. the speed of the fan and the draught produced wero proportional to the energy of the exhaust gases, and, therefore, the cooling effect was automatically adjusted in accordance with the load oil the engine. - A somewhat similar scheme has been utilised /or aero engines, in which an exhaust-driven turbine, running at 20,000 r.p.m., is used to force air to the carburettor and obtain a supercharging effect. This system lias considerable possibilities for motor-car work, albeit that a certain increase position than . the pistons as regards

W - -- ■ The West Australian motor-cycle championship was won by A. Johnson on an Indian. An invitation pianoforte recital given in Paliiatua last week: by Miss Zenobia Manson, L.T.C.L., one of Mr j Horace Hunt's pupils, attracted a large audience. It was the first recital nt the kind given by Miss Manson, and Upon its success she must be congratulated. Vocal items were given by Miss Mabel Mclntosh (pupil of Mrs Bryreson TrehOarne), and Mr Horace Hunt, who went to Paliiatua for the occasion, played the accompaniments. At its meeting the Longbush School Committee passed the follow, ing resolution: “This school committee views with alarm the. tendency cf those in authority to substitute experimental chemistry for practical agriculture in our schools, while_ Asiatics persistently and surely encFoach on our primary industry.”

in mechanical complexity ia unavoidable.

Aa regards' the utilisation of heat transferred to the cooling system, it is interesting to notice that a Diesel engine has been developed for marine purposes in which heat from the cylinders is used to raise steam. This strain* is conveyed to the cylinders acting on the same pistons as the explosive gases, aind considerably -in-crea-res the power available. The steam is working under very suitable conditions, because the cylinder is warmed by the exploding gases, and the steam tends to cool the piston. MOTOR FATALITIES BIG TOLL IN AMERICA. Four hundred and twenty-three lives were snuffed out during the month of March in automobile accidents reported to the National Safety Council in America, by the 80 cities having a total population exceeding 30 millions. Fifty of these cities reported 108 other public acclaerit iatalities; 37 cities reported 189 home accident fatalities, and 26 cities reported 67 industrial fatalities. The daily automobile death rate per million population increased from .359 in January and .437 in February to .49 in March. The greatest increase is found in deaths of children under 15 years of age. Deaths by accidents in the home decreased in March as Compared with February. Notable in the National Safety Council’s rrtpntbfly survey nre tlie faicts that male motorists were involved in more than 12 times as many accidents as female, and twice as many male pedestrians as female were injured. The most common circumstances attending the occurrence of accidents. as far as the motorist was concerned are “did not have right of way,” “exceeding speed limit,” “cutting left corners sharply,” “cutting in,” “on wrong side of road,” ana “motorist intoxicated.” “Walking, running or playing in the street” accounted for many pedestrian fatalities. “Going into the street not at intersection,” “riding or hitching on vehicle,” and “crossing intersection against signal,” were other common causes of fatal pedestrian accidents. The large majority of accidents occurred in daylight when the weather was clear jmd the road surface dry. Sixty pear cent, occurred at intersections. , . “Cities must provide ‘better playground facilities with proper and adequate supervision in order to keep the children off the street this summer and thereby reduce the growing fatality rate among children under 15 years of age,” says the National Safety Council in announcing the mohthly report.

SAFETY WEEK

MOTOR UNION SUGGESTED. One important question touched upon at the annual meeting of the South Island (N.Z.) Motor Union was that of putting propaganda work into effect in the matter of teaching the hopeless and hapless pedestrian his business. It was rightly suggested that an effort should b© made to inculcAte * safety-first principles in the impressionable minds of the children by vjay of essays_ and so on. There is ample scope for the motor unions to show, a lead in this matter. In the first place, safety first committees could be formed in each centre, the councils could be applied to for monetary help, essays in primary and secondary schools could be offered and the co-operation of teachers sought. A Safety First Week could be held with, stickers on windscreens, and an advertisement or two could help in stressing the rules of the read on the dyed-in-the-wool jay-walker. As motoring grows and grows, the motor unions of both islands might see-fit to pool funds and have a specially prepared film released showing \ how not to walk in traffic. Thousands of pedestrians test the hot radiators of cars in New Zealand annually, and are injured thereby; likewise thousands of cyclists come by injuries through carelessness. While the authorities of this country. are active enough regarding the control of motor vehicles, they entirely disregard the pedestrian. Drivers are controlled by teaching them what is right for them to do. and it is no use trying to control pedestrians if they are not trained in the ways that they should go. Auckland has nothing to be proud of in its pedestrian traffic; people old and young disregard all the rules of the road and walk here, there and everywhere, to their own hurt. A POWER IN THE LAND The motor unions of New Zealand are now becoming a power in the land, and the motorist is not now looked upon as someone outside the pale, although there are still a few. both motorists and others, who endeavour to discredit motorists on every occasion, the former by their disregard for the laws, and the latter by pinpricking wherever there is an offence against the by-laws. It is up to the motor unions to take up this work; commencing with the children, for it is through'' these that the majority of the people will become acquainted with the agitation that is going on. The first principle that will have to be instilled into all is that both the motorist and the pedestrian have their individual rights, and that those rights should be. respected on all occasions. . . Traffic control is now exercising the mirids of the civic authorities jn all parts of the world, and the time is ripe for something definite to be done. If a proper system was initiated, some of the great difficulties that are in sight would be obviated, and the streets would become safer for all kinds of traffic. - » -