WORLD ACHIEVEMENT

Manawatu Standard, Volume LIX, Issue 164, 13 June 1939, Page 11

WORLD ACHIEVEMENT

THE MERSEY TUNNEL. On December 16, 192.5, H. 11. H. Princess Mary switched on the power of tlie pneumatic drills—the work of building the Mersey Tunnel had begun. 1 loyal Assent was given oil April 26, 1928, to the scheme which was to provide lor both a dock and a Ira flic entrance oil both sides of the river. The cost was to be .1x5.222,000. Two down-shafts were driven—2oo feet in depth and 21 feet in diameter, one. at each side, close to the shore. During the building of the tunnel 1,200,000 tons of rock wore removed. On April 3. 1928, Sir Archibald Salvidgo broke through a thin _ wall with a pick axe, and in a few minutes the hole had been enlaregd by workmen to five feet in diameter. Then the Lord Mayor of Liverpool stopped through and said to flic Mayor of Birkenhead: “Liverpool greets Birkenhead.” They had met far below the river. The whole of the under-river section of the tunnel was lined with cast-iron rings built, up in segments that were rejected if there was an ihnecuraoy of 1000th of an inch. Each segment was bolted by hand, and the bolts, nearly a million of which were used on the entire tunnel, were fitted with bitumen washers, so that waterseepage was impossible from that source. The road surface of the famous tunnel is made up of nearly half a million square sections of cast iron, with ribbed undersides and studded upper surfaces. Those were laid upon the concrete finish of the roadway with the aid of a specially-made bituminous material. Olio section only, consisting of 2000 square yards of road surface where the tunnel passes over the Hirkenheed-Mersey Itailwsy, is surfaced with rubber instead of oast iron, to lessen vibration.

Tlie tunnel was opened on .Tilly If* 193-1, by King George tlie Fifth.—(L)