Minimizing Accident Risks.
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T THE RISK of being accused of repetition, we feel that we must continue in our campaign against accident risks which could, in many instances, be avoided. In several serious cases which have occurred recently the excuses of the drivers have been based on faults in the braking system. In one instance a driver is said to have stated that, feeling his foot-brake fail, he knew that he was in for trouble, as only the hand-brake was left. This, on the face of it, appears to show that the driver had previous knowledge that one of his brakes was, comparatively, ineffective.
The chassis makers can seldom be blamed. They usually provide means of adjustment which arc easy to use and give an extensive range for wear, and yet it often proves the case that full advantage is not taken of these means. Many drivers and—we regret to note—maintenance engineers often pass a vehicle as being in a satisfactory condition if it can be controlled on a steep hill by both brakes used simultaneously. This is apt to give a false feeling of security. A vehicle should never be allowed to run unless it can be stopped on the steepest hill which is met with in the course of its work, using either brake individually so that the other is always available in ease of need.
Only the strictest supervision will prevent many vehicles from reaching a dangerous condition, however many brakes be employed, for, by neglect, uI may become so ineffective as to be comparatively useless in emergency.
Some years ago we advocated the use of an auxiliary brake the control lever for which could be situated in such a manner as purposely to be inconvenient to use. By fitting such a brake, the driver would not be tempted to use it except in time of dire need through the failure of other means for stopping the vehicle. This idea was not taken up, but we again commend it for attention.
There are many causes of brake failure, and they should all be studied most carefully by the driver and maintenance engineer. Instances have been known where operating cams have actually turned right over as the result of excessive wear on the shoes ; drums sometimes wear so thin that they burst under pressure, and where compensation is employed this throws both sets of shoes out of action unless the compensation be limited in some manner. Another frequent source of trouble is the escape of oil on to the Me tien surfaces, which so decreases the stopping power that, although the brake may have been quite efficient in the strict sense of the term, the actual braking power may be halved. We have no doubt that before very long all heavy vehicles, and particularly those used for passenger work, will be provided with brakes acting on all four wheels, and we hope also to see incorporated in them some form of sprag device which will reduce the risk of accidents caused by involuntary backward running. There is no doubt that much can be done by the makers in future designs to assist in the prevention of accidents, and it is significant that the latest rigid six-wheeled vehicles produced in America have brakes acting on all four rear wheels, but we must again emphasize that no efforts on the part of the manufacturer can be of any great avail unless they be backed up by unremitting attention to running efficiency on the part of the maintenance engineer.
The Responsibilities of Main Road Traffic.
LAST WEEK we published an interesting letter from the general secretary of the National " Safety First." Association, dealing with certain views expressed by a well-known judge on the respective righta of main-road and side-road traffic. These views, which were widely published, may have led drivers to believe that main-road traffic has the right of way and precedence over that emerging from side roads. This is correct only in Scotland ; elsewhere in this country the rule is that anyone using the highway, whether a main road or a side road, must so drive as not to harm, or be likely to harm, any other person using the road, whether in a vehicle or on foot, and we believe that there are High Court judgments to this effect. This means that a driver. on a main road must always be on the look-out, not only for pedestrians, but for other vehicles emerging from other roads, even if these cannot be classed as main.
Defective Police Controls.
IN VIEW of the activity shown lately by the police in connection with commercial vehicles, a case -. recently decided at a London court is of consider1€ significance. A driver was summoned for running a heavy vehicle along the Thames Embankment at 19i. m.p.h., but the magistrate offered to adjourn the case for the purpose of making an official test when the owners of the vehicle stated that it was fitted with an engine governor which would prevent the vehicle from being run at a speed of more than 14 m.p.h. on a level road, Subsequently two inspectors were sent from Scotland Yard for this purpose, and the speed of the vehicle was checked over what was stated to be a recognized police trap. The result showed a maximum speed of 15i. m.p.h. The owners of the vehicle were still dissatisfied, as they had previously tested the vehicle themselves, and after the inspectors had left, the length of the control was measured by a surveyor on behalf of the proprietors, the Automobile Association agreeing to bear the expense in view of the importance of the case. The result was that the, so-called, furlong proved to be 18 yds. 1 ft, short. Consequently, the summons was dismissed and costs given against the
pol iee. .
The great importance of this case is that probably scores of users of motor vehicles had been fined as a result of tests over this defective control, and it throws a light on the haphazard methods sometimes employed. We are not amongst those who constantly cavil against the police, for we recognize that they often have difficult and disagreeable tasks to perform, and Bib if the law be broken it is of little use complaining against the penalties which are inflicted ; at the same time, every care should be exercised by the authorities in order to avoid injustice. Speed timing is a matter which can only be done with any real degree of accuracy by experts, and the law should not be invoked as a result of speed calculations upon which grave doubt may often be thrown. The motor vehicle owner usually has to bow to superior force, and it is not often that an opportunity presents itself for making a test similar to that described. It is quite probable, however, that if this could be done more often, other glaring diacrepancies would be found, The Effect of Engine Temperatures on Oil Dilution.
IT HAS long been known that in order to obtain the best results from an engine, in terms of power and consumption, the running temperature must be neither too hot nor too cold. Only recently, however, have researches been made which definitely show that the running temperature has a pronounced infiuenee upon the rate at which the oil becomes diluted with petrol. A diluted oil is not a good lubricant, BO that this matter, if neglected, leads to undue wear of the working parts and frequent renewal of the oil in the sump. The question of maintaining the correct running temperature is therefore one of considerable importance, but in most cases the driver can only try the effect of connecting and disconnecting the fan, blocking up part of the radiator, or leaving the bonnet partially open. He has no definite temperature control at his disposal. These crude methods cannot possibly be expected to ensure an equable engine temperature; particularly when one remembers the widely varying conditions of loading under which the average lorry is operated. Then, again, in the ease of the delivery van, frequent stops are made, so that the engine temperature never rises to an efficient figure throughout the day. It is therefore reasonable to conclude that there are very good grounds for advocating the use of thermostats on commercial vehicles, such devices automatically regulating the flow of water through the radiator in accordance with the temperature. On private cars thermostats have proved to be both efficient and reliable, and there are no delicate working parts which could not withstand the vibration present in a commercial vehicle.
One.way Traffic in Congested Areas.
ONE OF the partial solutions offered by the authorities for the alleviation of the traffic congestion wLeh is occurring in certain areas in London, particularly where market transport is responsible foe acute traffic difficulties, is the one-way system of control. Certain experiments.made by the Commissioner of Police foe the Metropolis have proved so successful that the system is being adopted in other.. parts of London where it has proved possible to direct return traffic through neighbouring thoroughfares, Obviously, the steps taken at present only touch the fringes of the matter, but as drivers become accustomed to this form of control it is likely that it will be extended to a considerable degree. Curiously enough, experiments in provincial areas in which similar control has been established have not proved entirely satisfactory and have even been abandoned after a short trial period. It will be interesting to observe if greater success follows London's efforts in this direction.