ELECTRIC TRAMWAYS.

Dominion, Volume 3, Issue 796, 20 April 1910, Page 6

ELECTRIC TRAMWAYS.

"CANNED CUEEENT" CABS. IS THE OVERHEAD' STSTEM. DOOMED? In connection with the .decision of the Invercargill City Council to introduce an overhead, trolly system of electric tramways, Mr. Scott Symington, consulting engineer to the Christchurch Tramway Board, in a letter to tho Mayor of Invercargill (says the "Southland Times") discusses the probability of the overhead system being.superseded by the storagebattery system. . • ■ "For the past ten or twelve years vague rumours have periodically been circulated in regard to Edison's researches in this direction (the storage-battery car), so much so that the subject has become to some extent a matter of amusement in engineering circles. No tangible result has yet been made public property, and, speaking .as a practical engineer, I can' assure you that there need be no fear of it ever displacing the overhead trolly system for towns or cities. While self-propelled cars, both, electric storage and petrol driven, are only in their infancy, and great developments may be expected during the next. few years, they can only be of use for long-distance travelling, and in cases where the great oxpense of the overhead trolly and electric power distribution scheme would counterbalance the expense of storage battery or other type ,of self-propelled cars with their corresponding losses due to their charging and maintenance, and the groat inconvenience which may be expected from such complicated cars. "In the case of systems where power can be generated at a central station 1 and distributed cheaply, I am absolutely confident," he adds, "that nothing will be able to compete with the overhead system for low operating costs, which will more than compensate for any increase there might be on the interest of the capital expenditure, and the additional cost of such cars would go a long way to meet the cost o,' the overhead construction. Looking at the/matter in another light, it is theoretically impossible to store power, without losses of from 20 to 25 per cent., which in a system such as yours would be a very considerable' amount, and in any case it would still be necessary to have a-power station for the generation of the electricity."