Electric Starters For Tractor

Content Tools

The following article is reprinted from The Country Gentleman, July 19, 1919 issue. It was sent to us by Pat Rixe of 1202 S. 211th Street, Catoosa, OK 74015.

When electric starting systems were first suggested for tractor motors four or five years ago, most engineers agreed they would be very convenient if they would work, but none of them believed they could be made to withstand tractor vibration. I know of several experimental installations that had to be discarded on that account.

The vibration of the tractor shook the clamping nuts loose on the terminals, displaced the spacing bars between the plates, broke down the supports for the plates, and even shook the paste out of the grids. Spring suspension under the battery boxes was tried, but that did very little good. The tractor engineers concluded it was no use experimenting any further and passed the word along the line that electric starting devices for tractors were failures.

At the time these experiments were made by the tractor companies, the market for such apparatus was limited and the storage-battery manufacturers thought it was not worth giving much attention. They were devoting their efforts to trucks and automobiles and other installations where business was more plentiful.

Then came the war, and there was a demand for motor trucks for the Army, with starting systems of sturdier make than had been used at that time in commercial work. The army engineers made up their specifications and invited the various manufacturers to submit samples for inspection and tests. The batteries all looked good and gave a good account of themselves on stationary tests, but that was not sufficient; they had to be able to withstand the hard service of the army supply trains over bad roads, with bad care and hard driving.

In order to make sure they would be able to perform reliably under these conditions, the army engineers devised a testing machine that would lift a battery three-eighths of an inch and let it fall on a hard, unyielding surface 480 times a minute, or 28,800 times in an hour. In thirty-six hours a battery received more than a million such shocks. It was a very severe test and the first batteries that were submitted went to pieces considerably under the half million point. In consequence of this poor showing, none of the batteries were accepted and the manufacturers all went back home to improve their products.

A few weeks later they returned, and, if I have been correctly informed, all of them went through the tests without serious trouble. All the batteries were able to stand two million drops on the testing machine without showing any signs of distress. The manufacturers had provided rubber supports for the battery boxes, had used thicker grids, more substantial insulators and better supports and distance pieces for the plates. They used better lock nuts for the terminals and turned out much better batteries. The improvement wrought in such a brief time surprised most engineers and was the subject of no little discussion among the profession.

In discussing the matter with an electrical engineer who has had many years of experience, he said, 'The battery makers knew all along how to make better batteries, but for years they had been trying to see how cheaply they could make them. Competition was sharp, and in order to get business they shaved down the thickness of the plates, used the minimum of material and produced a cell that would give fair service under favorable conditions.

'At the same time they were-making batteries for such service as electric lights for railway coaches, where the vibration is tremendous and the service much harder than on trucks. When they had to turn out a good product and were not hampered too closely by price, they had no trouble in fulfilling all conditions. It was not ignorance on the part of the battery people that was responsible for frail batteries, but business competition.'

Shortly after the government tests were made, one of the engineers read a paper before the Minneapolis branch of the Society of Automotive Engineers in which he predicted that tractors would soon come to the use of starting and lighting systems. The engineers present were skeptical and expressed lack of faith in storage batteries, even after having been shown the results of the tests. They believed tractor service is harder on a battery than any other kind. Engineers who are acquainted with the various kinds of battery service, however, tell me that tractor service is not very difficult. It is not so severe, they say, as trucks and automobiles, and does not compare with railway-car installations. The greatest difficulties arise from lack of care during the winter season when the tractor is laid up for several months.

If the battery is not kept fully charged it is likely to freeze. When a battery is fully charged it will stand any winter temperatures to be found in this country, but if permitted to run down it may freeze at temperatures even above zero. The proper thing to do is to remove the battery during the winter season and store it in a garage where it will be properly taken care of.

Altogether about 10,000 starting systems have been put on tractors in this country, and it was my privilege recently to examine all the service sheets. Those for March were particularly interesting because that is the month when the tractors were taken out of winter quarters and put to work. Out of the total number of installations less than one-fifth of one percent reported trouble, and in all cases this was of a very insignificant nature, such as loose or corroded terminals, which are easily repaired. Rust caused more trouble than either frost or vibration, and even that was negligible. If every other part of the tractor made an equally good showing, tractors would be more popular than they are.

It is always rash to prophesy what will take place, but when one considers how rapidly starting and lighting systems have been adopted by the motorcar companies, it seems reasonable to expect that tractors will follow the same line of development. No one likes to crank a gas engine. It is not only hard work but dangerous as well. Many broken arms have resulted from the kick-back of motors, and low-grade fuel does not make starting any easier. Most people would be glad to be rid of such trouble, and I have little doubt that before many years pass the public will demand electric starters on tractors.

This idea seems to be shared by a number of the more progressive motor manufacturers, because they are sending out their new engines with brackets to carry the generator and starting motor, and with gear teeth cut on the flywheels to mesh with the armature shaft of the electric starter. They are not as yet adding electric equipment as a part of their standard product, but if the manufacturers of the tractor wish to use such a system the motors will not need to be changed.