BREAKWATER BORES

Hawke's Bay Tribune, Volume XXIV, Issue 10, 22 December 1933, Page 7

BREAKWATER BORES

COMPLETION OF WORK No Rock Formation Founs STATEMENT BY CHAIRMAIJ Boring operations which have bee* carried out at the Breakwater Harbour during the last few weeks have revealed that the ocean bed in that locality contains no rock formation, according to a statement supplied Jp-day by the chairman of the Harbour Board (Mr T. M. Geddis). The work of the borings was finished last night, and the contractor, Mr W. Richards, of Hamilton, has, Mr Geddis reports, expressed himself as satisfied, after making 70 bores, that there is no rock in tho locality and that the material of which tho sea bottom is composed could easily be dredged with a suitable dredger. “An experience of more than 25 year* in boring and testing operation* i* the record ot Mr Richards.” Mid Mr Geddis in his statement. “For over a quarter of a century he has been unceasingly eii ,d in the work; in those years he has. to use his own words, had ‘solid going all the time.’ Almost constant 1 1 , he has had five plants working under tho direction of himself, assisvedby his son. The contracts which he has carried out have given, him Ml unusually wide and varied experience, involving a* they have done work of all classes. He has undertaken many contracts for municipalities, testing ground and ascertaining the nature of its composition for the purpose of water supply works; he has had extensive work in connection with factory schemes in many parts of the North Island; and he has been engaged with the Public Works Department on two of the leading hydro-electric schemes hi tho North Island—Arapuni and Tuai (Waikarcmoana)

CONTRACTOR’S REMARKS. “Nearly all the factory schemes undertaken in the Waikato and requiring boring operations to ascertain the nature of the ground material have enlisted the services of Mr Richards. Besides operating extensively in the Waikato, he has carried out borings in other parts of the North Island, including a contract at Fcilding, where, after three other borings contractors had abandoned the work, he secured a flow of water amount to 4,500 gallons an hour from a three-inch pipe. With the Public Works Department Mr Richards has carried out extensive contracts; he was engaged at Arapuni on four occasions, and on the last he was at the site of the hydro-electric scheme for two years, without a break, working three machines all the time. He was also at Waikarenjoana—which he described as a most difficult scheme, on account of the nature of the ground —engaged in testing the country, “Mr Richards ha s been surprised at the easy nature of the boring encountered during operation* at the Breakwater,” the statement continues.

“ ‘Taking the whole thing right through, I failed to get any rock whatsoever,’ he remarked. ‘I can honestly say that there was no rock whatsoever.’ “ ‘The only thing I struck,’ he added, ‘was a piece of hard stuff which had mud below it as well as above it, proving that, it was a piece of boulder lying in the mud—and it wa* a very soft boulder at that. That wa* the only bit of hard materia] I encountered. Most of the material which we struck was all soft papa, and I would say that it could be dredged very simply and easily with a suitable dredger. There may be difficulties to encounter on account of the stickiness of the papa, . but with a suitable dredger it should easily be done. BORES ON AUCKLAND ROCK. “ ‘We did 70 bores, with a total of 1,700 feet Jf material bored through,* said Mr Richards. ‘We went away out; past the buoys and the Auckland Rock, and over the basin enclosed by the Breakwater Mole. We also took borings—between six and nine—actually on the Auckland Rock. The borings, taken over the entire area, were sunk to a depth of 35 feet beneath the sea floor—in some cases down to 54 feet. On the sides of sites for the proposed wall, the borings were sunk to 50 feet below the sea floor. “ Bore after bore produced much the same material, except that the further out wo went we struck limestone mixed with the papa. The limestone and-papa mixture is softer than papa mixture. When wo were boring in it we had to follow the casing down quickly for fear the soft material would wash m and fill the hole. In .some places we also found a little shingle mixed with the other stuff, but the pebbles were very small. “ ‘The only rock down there at the Breakwater,’ said Mr Richards, ‘is in the form of loose boulders—and there are not many of them—which can be picked up quite easily. We had a special apparatus with us for boring through rock, but we never used it.’ “Even boring actually on top of the Auckland Rock was surprisingly easy, according to Mr Richards,” continued Mr Geddis. ‘ Between six and nine bores weie sunk on top of the roek, and in each case the result-was the same—the cutter went into about two or three inches of rock and then tell right through, showing tliat the Auckland Rock is merely a crust-of haid material about two or three inches in thickness, with soft material (liniestono and papa) underneath. ‘Altogether the job was far easier than | anticipated,’ said Mr Richards. <And now that we managed to finish last night,’ he added. ‘l'm going straight eft home for Christmas.’ “