London Carrier's Chief Engineer Says—
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Preventive Maintenance is Imperative
J. B. Oskr, of Carter Paterson and Co., Ltd., Stresses in 1..A.E. Paper the Need for "Stitch-in-Time" Inspection and Maintenance, Gives Valuable Advice and Draws Significant Conclusions
VEHICLES operated at high speeds have repair costs as V much as 50 to 100 per cent, higher than those opertiting at an average of 20 m.p.h.. A vehicle driven •always by the same man. often remains in good condition for many years. Instead of stating as sales propaganda that their vehicles can carry overloads, manufacturers should declare what loads the vehicles will carry without trouble, and recommend that they be not exceeded.
These and many other words of wisdom are contained in a paper headed "Repairs and the Repair Depattment," by J. B. Osier, chief engineer, Catter Paterson and Co„ Ltd., published in the February issue of the I.A.E. Journal. Mr. 'Osier is welJ qualified to lay down the law on matters such as these, and, as might be expected, the whole paper is .full of common sense and advice of value to all lessexperienced or less-able maintenance engineers and to the war effort.
Summarizing maintenance methods, the author says there are two main systems--(1) to run the vehicle until it breaks doivti, and (2). to bring it in at stated periods for inspection by skilled mechanics a..pd the rectification thefe and -then of all faults detected.
He regrets that system No. 1 is still in vogue among some .smaller transport organizations, but qualifies this expression of opinion by referring to the common practice that existed hal:ire the War of buying vehicles on an agreed repurchase basis that came into effect after two years of
n fling..
50,000 Miles Freedom From Trouble
This scheme has both advantages and disadvantages, he points out. Among the former are that the operator may expect freedom from serious trouble for 50,000 miles, that the manufacturer has a regular Market at two-yegrly intervals, and that the agent has a regular supply of work for his repair shop and of used vehicles for sale.
As disadvantages, he names that a reconditioned vehicle sold to a competitor of the original buyer seeme,„ on the face of it, to besubsidizing that competitor, that the price paid for the Worn vehicle depends on that received for it when reconditioned; that if the vehicle, after reconditioning, is unsuitable for operation by the first owner, it should be unsuitable for any other operator, and that the system can function only if a market for reconditionedvehicles exists.
Employing.system No. 2, Mr. Odor's company has all vehicles in for inspection between 5,000 and 7,500 miles; The inspedlbrs work to a chart, which it given as an appendix to the paper and is by no means the least useful part of this engineer's contribution. - Maintenance he divides into seven sections: —(1) Keeping the vehicle clean; (2) lubricating it; (3) attending to drivers' reports of faults:(4) inspecting at regular. intervals; (5) replacing damaged parts; (6) overhauling; (7) embodying design improvements. First three of these come uncle.; system No. 1, but all are included in system No: 2.
.Under maintenance section 1, be stresses the need for makers of chassis to go farther in the matter of grouping lubrication points and boxing them in. When nipples are exposed, even if the dirt be wiped oil before applying the gun, some remains in the orifice and ultimately finds its way to the seat of lubrication, with disastrous results.
To emphasize the importance of cleaning from the maintenance aspect, he remarks that at a depot where the drivers keep the vehicles thoroughlyclean only half the .number of mechanics is found necessary that is required at a depot where the vehicles are allowed to get into a dirty state.
Coming to Section 2, the author advises the provision of lubrication charts, and emphasizes the need for taking all 'posiible steps to overcome the difficulty of supervising inbricationL–of making sure that it really is done properly and thoroughly. Facilities must be afforded to drivers for notifying complaints' about their vehicles and they should be attended to at once.
By becoming familiar with specific types of vehicle, mechanics can learn which things need daily examination, and so forth. At least weekly inspection should he made, M. nearly all cases, of brakes for adjustment, electrical equipment working, Ian' fixing, fan-blade fixings, firefighting apparatus, spring U-bolts, water connections, screen wiper and wheel nuts.
The comment following this list tells unmistakably of the knowledge Mr. Oster possesses of practical difficulties. " All this sounds easy," he says, " but is not quite so," adding that those responsible for operating the traffic are usually too anxious to get the vehicles on the road, and if the mechanic is not quickly on the job he win find the vehicle has 'gone.' S The greatest possible co-operation between engineer 'and traffic manager is essential: 'The latter should realize triat with this sort .of maintenance a mileage of 100,000 or even 200,000 is prissible without overhaul.
With regard to the replacement of worn parts, decisions can be made by knowing. what degrees of wear are permissible. In. fixing these the designer can help the maintenance engineer.
An overhaul, says Mr. Osier, is the complete dismantling of a, vehicle and an eicamination of every separate' item, with the necessary repairs and then re-assembly. An overhauled vehicle should.be 8§ per cent, the equal of a 'new one and good fotat least 85,000 miles.
• Maintenance Includes Improvement
Under Settion 7, he advocates that a close watch be kept on progress and tile possibility of adapting .new ideas to existing vehicles. On the other hand, where a specific fault keeps on cropping up in vehicles of a certain type, it is up to the maintenance engineer to remedy the fault either by redesigning the part or taking some steps to relieve it of the demise of stress that it is obviously incap able of withstanding. f
In connection with the organization, he touches on the difficulties of deciding what number of staff is required for a given number of vehicles.. However, where the machines return regularly every day to their base, he suggests about one man to five vehicles . where they are not kept well cleaned and one to ten where they are.
He has found the "split shift" convenient and many of his company's mechanics work from 6 a.m. to 10 a.m, and from 5 p.m. to 9 p.m., thus being on duty when the vehicles are available in the garage.
Men who, besides being able to effect repairs, can carry out inspection, he remarks, are scarce, as well as reliable diagnosers. He also values partkularly employees who are expert at retrieving vehicles after accidents.
Finally, • he stresses the imporinnce'of standardization by manufacturers, quoting as examples radiator and tank filler caps, wheels for similar tyre sues and the methods of securing them. ,A great deal can yet be done by the designer in this respect, he.comments.. As we implied earlier, the inspection chart is comprchensive'and clearly the outcome of long knowledge of -practical requirements. If more operators based' their maintenance system on this list of inspection operations, not only would it be to their direct adyaatage, . but it would also raise even higher than at present the efficiency of road transpprt as a whole.