NEW TYPE OF SEA WALL

Sun (Auckland), Volume III, Issue 753, 28 August 1929, Page 11

NEW TYPE OF SEA WALL

DEVONPORT EXPERIMENTS PROTECTION FOR ROADWAY Devonport is experimenting with a l ,yi H ' of protective sea-wall along the Narrow Neck beach frontagef. ihe concrete road here runs along y, rr F w strip of land only a few feet above high-water mark, and it was close to destruction during a severe storm in 1926. The borough engineer, Mr 4. T Griffith, found that the beach consists of a sand mat carried by mud resting in a V-shaped valley that was once an outlet for the Waitemata. He reported to the council that the ordinary type of wall with a “toe” into the sand would give no permanent jirotection. and suggested that concrete slab-piles weighing between nan a ton and a ton should be driven mto the papa rock foundatlo“- T his is now being done. The piles are interlocking. They are lowered into position through a water jet at their lower end, removing the sand until rock is encountered, when the usual type of piledriver can be used. Several piles, w-hich will later be used as an anchorage on the landward side, have already been driven by the contractors, Messrs. Jones and Gifford. It is hoped to complete the work before the end of the year, and to lorrn an esplanade between the wall and the roadway during the coming summer.