NORTH MOLE

Timaru Herald, Volume CXLII, Issue 20509, 29 August 1936, Page 7

NORTH MOLE

ALTERNATIVE PLAN DISCUSSED TWO SCHEMES BEFORE BOARD ENGINEER TO PREPARE ESTIMATES The estimated costs of Captain H. C. White’s scheme to improve Timaru Harbour by an extension of the North Mole and an alternative scheme submitted by the engineer (Mr B. W. Charman) are to be prepared by Che engineer and presented to the Board. This decision was arrived at by the Board at yesterday’s meetipg, when the engineer’s scheme was considered. The standing committee reported that the engineer’s scheme had been considered by it. A letter had been received from the Minister of Marine (Hon. P. Fraser) advising that should the Board promote the necessary legislation, the Royal Commission might be discontinued, and all members affirmed the principle of obtaining additional advice in place of the Royal Commission. The committee recommended that the engineer prepare estimates for the amended scheme in addition to that of Captain White’s or any other scheme. Immediate Needs The Engineer stated that the scheme was, after careful consideration of the recommendations of the 1928 Harbour Commission, of the present requirements of shipping, and more particularly of the probable future requirements of Che port. The immediate requirements of the port, from a navigational aspect, were increased manoeuvring area and a straight entrance channel. Any improvements that might be effected must make provision for not only the class of vessels at present trading to the Dominion, but provide for the safe handling of even larger vessels in the future. “Any alteration that may now be effected to the enclosed water area of the harbour must also provide for the construction of additional wharves in the future without the necessity of

again having to alter the enclosed water area of the harbour.” The accompanying table gives a comparison between the existing state of affairs and the state of affairs that would exist if Captain White’s scheme, or the amended scheme, was adopted, the first set of figures being the present harbour, the second Captain White’s scheme, and the third the amended scheme:— Area of harbour: 50 acres, 56.6 acres, 60 acres. Manoeuvring area: 24.7 acres, 31.3 acres, 38.7 acres. Percentage increase in manoeuvring area: per cent., 26.7 per cent., 56.6 per cent. Available berthage room for future wharves at North Mole: 1,350 lineal feet, 1,900 lineal feet, 1,700 lineal feet.' Estimated dredging required to complete new entrance channel: dredge roads, 1,190 dredge loads, 1,190 dredge loads. Estimated quantity of stone to be lifted from North Mole wall and deposited on new alignment: tons, 61,110 tons, 124,445 tons. Length of new wall to be built: lineal feet, 450 lineal feet, 1,200 lineal feet.. Estimated dredging required to dredge out new swinging area and to found new wall in 33 feet of water: dredge loads, 345 dredge loads, 867 dredge loads. “The estimated amount of dredging required to complete the new entrance channel . is 1,190 dredge loads. The essential dredging that is required before the new alignment of the entrance to the inner harbour could be utilised is estimated at 400 dredge loads. Dredging Operations “In view of the p*'obable construction in the future of a wharf adjacent to tlie North Mole, it is essential that the new wall be founded in sufficient depth of water to ensure its stability when a deep water berth is maintained at the proposed future wharf. In estimating the dredging required it has been assumed that the whole length of the wall would be founded in a depth of water 33 feet at L.W.O.S.T. Tliis provision has been made in both Captain White’s scheme and the amended scheme. It also provides for the entire new area incorporated in the inner harbour to be dredged to the depth of 33 feet below LW.O.S.T. It will be seen that the estimated quantity of dredging required to be carried out to found the wall in 33 feet of water at L.W.O.S.T. and to dredge the new manoeuvring area to the same depth is as follows: Captain White’s scheme 345 dredge loads, amended scheme 867 dredge loads. “An estimate of cost cannot be sub-

mitted at the present moment as essential information regarding the estimated cost of plant and material has not yet been received from England. An indication from the Board, however, would be appreciated at this stage as to whether or not the Board wish detailed estimates of cost to be prepared for the amended scheme. “The attached table shows a comparison between the leading dimensions of vessels trading to Timaru, both before and subsequent to the building of the North Mole. The North Mole was completed in 1890. The tonnage of the largest vessels trading to the port of Timaru are:—

Size of Ships “In 1906 the largest vessel to trade to the Dominion, the Athenic, visited the port of Timaru. This vessel was 500.2 ft in length, and 63.3 ft beam. The longest vessel to visit Timaru is the “Northumberland,” with a length of 530.4 ft, which first visited the port in 1917. The “Akaroa,” 550.7 ft in length, which is the longest vessel at present trading regularly to South Island ports is not permitted to visit Timaru. It would therefore appear that in 1917 Timaru had reached its ultimate limit with regard to the length of vessel that could be safely handled. It will therefore been seen that the building of the North Mole made provision for the development of shipping over a period of 27 years only. “During the past few years the beams of new vesels have shown a steady increase, naturally there is an enomical limit to the beam of a vessel in relation to its length. If vessels are to be still further increased in size, it is more likely that an increase in length will take place rather than an

increase in draught for obvious reasons.

“In making provision for the future requirements of shipping that will trade to New Zealand it would appear that any alteration to the enclosed water area of the harbour should make provision for vessels 650 feet in length and having a beam of 85 feet. The tourist trade is comparatively in its infancy in New Zealand; the visit of tourist class vessels to South Island ports will, without doubt, be encouraged and developed in the future. “Since Timaru is the natural starting point for tourists visiting Mount Cook, and the lakes district, it would appear reasonable that when alterations to the enclosed water area of the harbour are effected, provision should be made for the safe handling and berthage of the tourist class of vessel which at present visits North Island ports. It would appear, therefore, that if provision is mads, for vessels up to 650 feet in length and 85 feet beam, the requirements of the port wil be satisfied for a very considerable period.” Proposals Explained The engineer and harbourmaster were, present during the discussion and in an explanation to the Board the engineer said that the amended plan provided for removing the whole of the outer end of the North Mole from a point in line with the end of No. 3 whalf. The mole would be extended 820 feet in a nor-easterly direction parallel with the store breakwater at the end of No. 1 wharf. At the end of the new 820 ft of the North Mole a wall 1200 ft. in length would be constructed at right angles. Provision was made for the construction of two . new wharves on the inside of the North Mole, 820 ft of berthage on the new section and 880 ft along the old section. The improvements would increase the swinging room in the inner harbour by 44 acres. Additional Expenditure Whatever scheme was adopted said the chairman (Mr T. B. Garrick), the Board had practically rid itself of the need for a Royal Commission, but the Standing Committee considered it would be necessary to call in the advice of a consulting engineer and a nautical man. The committee recommended that the engineer go into the costs of both schemes, but was the game worth the candle? At a long shot the engineer’s scheme would cost £70,000 more than the harbourmaster’s, but did the Board think it would be advisable to have two strings to its bow? When working out the estimated cost it would not bother the engineer much more to give the costs of both schemes which could be placed before a con-

sulting engineer. The extra money required for the engineer’s scheme, could, the chairman thought, be used for improving the Eastern Extension, while it had to be remembered also that the Board was faced with the provision of cranes and other wharf improvements. Why go further than Captain White’s scheme? Captain White contended that his proposals would allow more swinging room and that the scheme would be sufficient to meet present needs. Mr A. F. Campbell emphasised that it was advisable to look ahead. In future it might be necessary to carry the wall further out. “We could discuss this all day,” said Mr D. C. Kidd, who considered that the engineer should be asked to give an estimate of the cost of both schemes. It was all a question of finance, said Mr R. S. Goodman. The Board wanted to secure a, scheme that would meet present day requirements and one that could be altered later. He was in favour of Captain White’s scheme and he thought that the engineer was too. The harbour was quite big enough to meet present day requirements and under Captair White’s scheme it could, if necessary, take double the shipping. What was wanted was deeper water, cranes and better working facilities on the wharves. Deeper water was wanted outside and the only way to get that was to change the course of the channel. If Captain White’s scheme were adopted sheet piling could be used so that alterations could be made as demanded. That time, however, would not be in their lifetimes. He felt that the only thing t> do was to get a scheme which would meet present requirements at a minimum cost. While a consulting engineer was necessary, it was also desirable to have further nautical advice as to swinging room and as to whether Captain White’s scheme would be sufficient for the Board’s requirements. Mr D. C. Turnbull said he was of opinion that the Board was a trifle astray as to the functions of a consulting engineer. The idea was that the engineer’s and harbourmaster’s schemes would be considered by a consulting engineer and a nautical man in preference to a Royal Commission. If approved by the outside authorities and the Board, a scheme could then be submitted to the ratepayers. The Standing Committee’s recommendation was unanimously adopted.

Year. Vessel. Tons. 1883 .. Rangitiki 1,227 1885 .. Rangitiki 1,227 1890 .. Nairnshire 3,720 1895 .. Rimutaka 4,473 1900 .. Aotea 6,364 1905 .. Delphic 8,273 1905 .. Gothic 7,755 1906 .. Athenic 12,234 1910 .. Athenic 12,234 1915 .. Corin thic 12,231 1917 .. Northumberland .. 12,160 1920 .. Hororata 11,243 1923 .. Rotorua .. .. 12,184 1924 .. Hertford .. 10,923 1925 .. Corinthic 12,367 1930 .. Ionic 12,352 1935 .. Waipawa .. 10,700 Dimensions of largest vessels trading to New Zealand: — Vessel. Tons. Length. Beam. Strathaird .. 22,284 638.7ft 80.2ft Mariposa .. 18,017 604.0ft 79.3ft Aorangi .. 17,491 580.1ft 72.2ft Akaroa . .. 15,128 550.7ft 67.4ft Rangitiki .. 16,698 531.0ft 70.2ft