13-FOOT SENTINELS TO GUARD CALIFORNIAN ROADS

Shannon News, 8 June 1928, Page 4

13-FOOT SENTINELS TO GUARD CALIFORNIAN ROADS

Six-legged tetrahedrons, tethered by steel cables, are being employed to guard the motor highways of California. ,

Recently one of them . got away, but was captured within a quarter of a mile of his post, and his sevon tons of bulk was promptly hauled back, by a powerful tractor, to where he bolonged. . ' ' No, these are not strange antede luvian monsters recruited to guard the wayfarer along the Pacific Slope, but geometric sentinels of concrete, designed to prevent the temperamental rivers of this State form eating away the highways. Where brush and rock works have failed to hold off the flood waters of a river from a paralleling road, a group of these 13-foot high skeleton tetrahedrons have been placed along the bank of the stream, laced together with steel cables, arid in every case have vanquished the high waters. As broad on one base as on another, even if overturned, the tetrahedrons continue to resist the surging river. When flood times come, they and their connecting cables quickly stop tho brush, trees and miscellaneous debris borne .downstream, ami soon a natural barrier is formed which causes the waters to slacken pace, drop their heavy load of silt, and thus reinforce the baA rather than destroy it.

The tetrahedrons cost the State .about llSdol. each, and their protection averages a little more than 7dol. a lineal foot, which is considered cheap as an alternative to having farm land and a motor highway shift from one country to another, during a single period of high water. The one which got away was the last of a string, and had not been anchored to his brothers. When tho iflood came he resisted stubbornly, and the fact that it was undamaged and moved only a quarter of a milo was considered an excellent record for a river bank protector.