LINKED AT LAST.

Auckland Star, Volume LXV, Issue 122, 25 May 1934, Page 3

LINKED AT LAST.

SHORE AND CITY.

WATER PIPE LINE LAID.

IN USE IN FORTNIGHT.

Without hitch of any kind, and aided by perfect weather, the most difficult stage in the laying of the pipe line across the harbour to connect Birkenhead with the city water supply was completed this morning. The particular task carried to such a satisfactory conclusion was the putting in approximate position of the half-mile length from, roughly, the end of the Point Chevalier reef to join with the Birkenhead main on the sTiore very near Kauri Point. An attempt was made on the early morning of May S, but owing to the fact that everything went wrong, weather and machinery as well, it was not successful.

Hiis morning the water was as calm as a mill pond, and nothing untoward occurred; and just at 9.30 the end of the main 011 the beach near Kauri Point was connected with the main from the other side of the harbour. A few brief instructions, the consequent unlocking of a screw, and the first water ever to flow from a North Shore reservoir through pipes leading citywards, gushed through those laid this morning. Task Not Completed. That, however, docs not mean that the task is completed. It will be another two weeks yet before the whole line from the dam at Waitakcre to the reservoir is ready for use. All that was done this morning was to complete the trans-harbour section. There yet remains to bo done a gap 011 the city side, of seven-eighths of a mile, from the beach to low water mark.

Strictly speaking, explained Mr. A. D. Mead, waterworks engineer, who was in charge of the work, the task was not begun this morning, but at low water at t> a.m. yesterday. At the foot of Garnet Street, Ponsonby, the two lengths of pipe line to be used were lying in the mud. These were laid out oil sleepers on parallel lines, and at high tide, 3 p.m., they were floated out, one end being joined to the other, to make one long liiie instead of two. There it was left to settle when the tide fell again. Two men stood by to see that when the tide began to rise the line would still be in position. An hour before high water this morning, at 2 a.m., a small party arrived with a launch and started to tow the pipes over the shallow portion of the harbour, roughly parallel with the Point Chevalier reef. Beacons had been placed and lit at low water edge and at the edge of deep water, to show the course to be taken. Waiting at Anchor. By the time an hour had elapsed, the party was on the edge of the navigable channel —deep water —where the for'ard end of the pipe line was anchored, the other end being allowed to swing away with the outgoing tide. There the party remained at anchor until the tide began to ebb, and the critical time of the laying of* the length on the harbour bottom came. By 7 a.m. additional launches had arrived, bringing the total up to six. By the time all arrangements as to the towing procedure had been finalised, and ■the journey commenced, an hour had passed. Two launches were drawing the line,, and the others were keeping j the pipes straight. The towing time was only half an hour—but a most critical half-hour.

The foremost end of the line was taken right to a point near the Birkenhead end of the main, near which barges were moored. There, after manoeuvring which looked most complicated, and after half an hour's orderly confusion, the two mains were joined. All that now remained was the sinkof the pipe line. Mr. Mead knew precisely the nature of the harbour bottom. as he had had a diver examine it. It is shingly, with very deep potholes here and there. He expected that after a tide or two the pipes will be covered, and there they will remain for tne next 90 years —or more. Two sets of floats had been used to keep the pipes afloat, a larger and a smaller set, the latter beiii"- placed at closer intervals. When the ends of the mains were joined at Birkenhead, the larger floats, which were lashed to the pipe with ropes, were cut away with an axe, while the remainsmaller floats, just sufficiently buoyant to float the weight of the pipes, were mincturcd with a spike hammer. Without their buoyancy, the pipe line sunk —the task was finished. To give weight to the pipes, the water was turned on from the Birkenhead end, and so flowed the first water from North Shore to city. A Knotty Problem.

A knotty problem to solve was the actual joining of tlie mains, for the bed of the harbour falls away from Kauri Point at a grade of one in three, the maximum depth met with being 83ft. The join was made by the use of a pipe with a special flange spring bend of 20 decrees. The unevenness of the bed was another factor, to overcome which Mr. Mead placed flexible ball joints at points, while bags of concrete will support the line where necessary. When the laying of the -main in that particular fashion —sinking and floating —is completed, it will be the longest of its kind in the Dominion and one of the longest in the world. It has been no mean undertaking.

Among those to' witness operations wpre the Mayor of Birkenhead, Mr. G. Mills, and officials of the borough and of the Auckland Harbour Board.