THE QUEEN'S WHARF.

Dominion, Volume 4, Issue 1084, 24 March 1911, Page 8

THE QUEEN'S WHARF.

KESULTS OF EXAMINATION. "A recent examination of tho Queen's Wharf," reports the Harbour Board's engineer, "shows that the stringers and caps are in very bad order; they are principally birch, and are very much decayed. It will be necessary to rebuild the superstructure at an early date. Information is now being obtained to enable th© timber to be ordered and the work put in hand." When the condition of the muntz metal bolts in the (Jueen's Wharf was noticed, he continues, a careful examination was made of the sheathing and metal bolts in other wharves. It was found that all of the muntz metal bolts used during the last, ten or twelve years were interior, and would have a shorter life than tho metal which had been put in service many years ago. Sample bolts taken from the Glasgow and iiailway Wharves, although only in,,use nine and five years respectively, showed marked deterioration. "As noiv made, this metal does not appear to be suitable for the purpose for which it is used," continues the engineer. "The sheathing now in use is inferior to the old sheathing furnished in years gone by. In tho ease of tho King's Wharf, which has only been completed 21 years, tho metal bolts and sheathing were found to be deteriorating very rapidly. Some of the bolts were so corroded at their ends that the nuts were almost dropping off. The appearance of these bolts was entirely different to the older muntz metal bolts. It was found on analysis of the centre portion of a bolt that there was 1.6 per cent, of iron and 1.3 per cent, of lead, 54.4 per cent, of copper, and 41.7 per cent, of zinc, whereas muntz metal contains GO of copper to 40 of zinc. Tests made with -a delicate voltmeter! showed that when a rod of tho King's Wharf metal and a niece of sheathing were immersed in salt water and in contact, a current passes between them. This would account for some of tbe corrosion which has taken place. The metal bolts in tho King's Wharf will have to 1m renewed very shortly. The cost of such renewal will add very considerably to tho maintenance charges. In the meantimo renewals are being made with naval brass as required, but tho matter has been taken up with the manufacturers with a view to obtaining a metal at a reasonable cost which will satisfactorily resist corrosion in sea water. It is interesting to noto that a copper bolt which was taken out from the tirst-built part of the Queen's Wharf was in nerfect "good order after forty-eight years' use. A cast gunmetal bolt was also in good order. It is very questionable if copper rods and sheathii.g can be improved upon for this purpose."