Mr. R. J. Evans’ interesting letter about early car electrical systems, particularly those of CAV, underlines how the English manufacturers lagged behind the Americans in this department. Although the frictional contact drive of the 1914 CAV starter may have worked well on a sleeve-valve Daimler, I think Mr. Evans will agree that the resistance of thickened oil on a cold winter’s morning could usually defeat it. It was also surprisingly reactionary of CAV still to rely on a free-wheel clutch and manual charging switch, instead of an electro-magnetic cutout, because despite the free-wheel being deliberately made noisy, drivers not infrequently forgot the switch and an overnight halt with the dynamo “motoring” was quite enough to discharge the battery. The automatic cut-out, in one form or another, had been known for many years and various devices are described in my 1889 edition of Spon’s “Workshop Receipts”.
By contrast, American “electrics” were very advanced and, as is well known, Cadillac were ahead of the field in fitting electric lighting and starting sets as standard equipment, not as expensive extras, in 1912. In the same year Lanchester cars were supplied with probably the most elaborate and beautifully-made electrical equipment ever fitted to a standard production model. The basis of this was American, Delco indeed, and the general mechanical design and lay-out were according to George Lanchester’s specification.
The equipment consisted of a powerful “dynamotor” driven by a silent chain through a silent “escargot” free-wheel clutch from the propeller shaft. The free-wheel was needed to allow the generator to function as a motor without having to propel the car. At its forward end the machine drove through a six-to-one epicyclic reduction gear to a pinion which was manually slid into mesh with the toothed flywheel by the switch lever. So far, the arrangement was similar to that of the contemporary Cadillacs, but one of the refinements of the Lanchester system was that although the generator windings of the dynamotor worked at 8-volts pressure the motor windings were arranged to accept current at 32-volts pressure and ingenious series/parallel switchgear made the transition possible. The object of the exercise was to avoid the effects of voltage-drop in the starter circuit in cold weather, and similar series/parallel arrangements were found on some of the luxury cars, including Talbots I believe, of the ‘twenties. The Delco-Lanchester equipment not only included an automatic cut-out but an automatic charging rate regulator some twenty years before such devices became common.
Another very advanced early American system was the USL flywheel-dynamotor fitted to some of the pre-1914 Sheffield-Simplex cars. This was a beautifully made piece of work, which anticipated the DKW “dynastart” by a quarter of a century, but, like many direct-coupled dynamotors, it could be defeated on cold mornings by the gummy resistance of thickened oil.
For misplaced ingenuity perhaps one cannot beat the “electrickery” Mr. Dowsing fitted to his 1896 Arnold carriage. This included a dynamotor powerful enough not only to start the engine but to propel the car in town traffic or in the event of a breakdown. With the batteries needed for such a large electrical load one feels the Arnold’s 1-1/2 h.p. engine may have been slightly overburdened.
Anthony Bird – Potbridge.