STOCK AND SHOCKS

Evening Post, Volume CXXIV, Issue 89, 12 October 1937, Page 11

STOCK AND SHOCKS

PECULIARLY SUSCEPTIBLE One of the special reports brought before the power board engineers' conference sitting at Electricity House was one prepared by Mr, N. G, McLeod, engineer to the Thames Valley Electric Power Board, dealing with the susceptibility of stock to electric shock. Horses and cattle, Mr. McLeod stated, were far more susceptible to shock, and fatal shock, than were human beings. . The particular case which led to the report occurred at Morrinsville in September, when a horse was electrocuted through a Jive low-tension wire sagging and coming into contact with an earth guard. The guard was connected to earth, but the earthing was not complete, and the current flow was not Sufficient to open the protective devices which would have cut the current oil. It was not possible to determine what voltage the horse received: it could have been as high as 100 volts, but wes probably less. Case 3 were on record of horses being killed with potentials of no more than twenty volts between their fore and hind legs, and one . case, was recorded of a pressure riot exceeding 12 volts, or the voltage of an ordinary six-cell car battery, proving fatal, Human beings in normal circumstances could withstand considerably more than 100 volts without discomfort, and shocks of 230 volts, while distinctly unpleasant, rarely proved fatal to human beings, unless prolonged.

In the case of the livening of the ground, the position was doubly dangerous to the larger animals, first because of their greoter susceptibility to electric'shock, and secondly because of the greater, length they covered in passing over the ground, and whereas a horse in its stride might be subjected to a large percentage of an earth fault potential—fatally if it was of. any magnitude—a human being would not be conscious of any untoward circumstancc.

The remainder of the report discussed the safeguards employed in New Zealand and in overseas countries.