THE OTIRA TUNNEL.

Rangitikei Advocate and Manawatu Argus, Volume XXXIII, Issue 9139, 7 May 1908, Page 7

THE OTIRA TUNNEL.

OPENING CEREMONY. Per. Press Association. ~~ Ofcira, May 5. The West Coast deserved its name of the West Coast yesterday, when the opening ceremony of the Otira tunnel took place. During the night a north-westerly gale sprung [up accompanied by thunder and lightning, 'and this morning' the rain [came down in torrents and continued to fall throughout the day. A great disappointment was felt at the Christchurch visitors being stuck up at the Bealey owing to the high state of the river. The Railway Department had mdae elaborate arrangements for carrying three thousand people and only about three hundred braved the elements, including Lady Ward and several ladies. At Otira the weather was wretched, the rain coming down as is only known to West Coasters. The, Otira river was running bank high, and the'walk of the two miles to the tunnel site was anything but agreeable. On arrival at the scene of operations, Mr Bruce, county chairman for Westland, was introduced to the Premier, and expressed the pleasure all felt at the commencement of a Work that was of national importance.

The Hon. Guinness explained the active part he had taken since 1885 in the movement for the coupling of the Midland railway. Mr O’Halloran, the only Canterbury representative who had got through, said it was a proud day for him to take part in the ceremony of starting the “hole in the hill.” (Applause.) Sir J. G. Ward was greeted with cheers when he rose to speak. He stated that the work that they were commemorating to-day was one of historical importance. He was confident that the Government were only studying the welfare of the community in letting the contract. He traced the great progress the West Coast had made during the last five years, not only in population but in industries. The West Coast would show out in importance and the rich resources of the district would be developed. The timber industry had made rapid'strides, and the export had reached 51,000,000 feet V 1 anally. The coal export had increas'd considerably, and the flax industry was satisfactory. The resources of the West Coast were enormous, and the opening of the railway to connect Christchurch would be the means of developing the Coast. He felt sure that to-day would mark an epoch in the history of the coast. The Government had done right in forwarding this great work, as it was due to their late chief, the late Right Hon. Mr Seddon. If the present Ministry had not taken the responsibility they would have been accused of cowardice. He regretted that so many enthusiastic citizens of Canterbury had been delayed at Otira. The Premier then touched; the electric button and the first shot of the Otira tunnel was fired amidst great cneering. Mrs McLean then presented Sir J. G. Ward with a handsome silver casket, suitably inscribed, as a memento of the occasion.

Sir J. G. Ward thanked the contractors for their kind present, which he would cherish. He wished the contractors every success in the undertaking. Three cheers were then given for the Premier and contractors, and an adjournment was made to the banquet hall, where a pleasant hour was spent. Speeches in commemoration of the occasion were made and the Premier thanked and cheered for taking part in the gathering. The party left Otira at 6 o’clock for Greymouth, well satisfied with the onting, "although the rain throughout the day did not cease for one moment. THE TUNNEL. FIVE MILES THROUGH THE HILLS. A tunnel five miles long ’had no place in the Midland Railway Company’s scheme. The company|lntended to deal with the great grades over Arthur’s Pass, 3000 feet above sea level by an incline system, adopting either the Pell or the Aht method, and making the trains crawl up one side of the range, and run cautiously down the other. The Government, however, when it took control of the work in 1895, decided that it would he better to go right through the range, aud plans were prepared for the greatest tunnelling project in the Southern Hemisphere, and for one of the sis largest tunnels in the world. To he exact, the length of the tunnel will he five miles twenty-five chains twelve feet. It will he seventeen feet high and fifteen feet broad. It will be quite straight, with a dip from the east to the west. The eastern portal will he 2435 feet above sea level, and the western portal 1585 feet, giving an incline in the five miles of ’BSO feet, or one foot in 33. Messrs John McLean and Sons have contracted to make the tunnel for £599,794. “Extras” will probably bring the total cost up to £600,000. It has been calculated by a person fond of figures that the (tunnel will he 332,640 inches long, and it (will cost nearly £2 an inch along its whole length. The workmen inside the tunnel will be, on the average 700 feet below the mountains, but at one spot, beneath Warnock’s Knob, they will burrow at a depth of 1100 feet. The contractors have already prenared their plans for the attack upon the ranges. Electrical appliances will he used to a great extent, and as a means to this end the waterpower available will he brought into requisition. If steam-power were used, there would be no to the trouble and expanse of carting the fuel. Water-power, on the other hand, will he cheaper, and it is thought, more efficient. The contractors believe that all the jiower they will need at the Bealey end can he obtained from the Devil’s Punch Bowl Falls, about half a mile from the mouth of the tnunel. The water there has a direct fall of about 450 feet, and an available fall from the top of 700 feet, and it may give 1000 horse-power. If it fails, there are other sources close by which can be relied upon. At the other end Holt’s Creek and other streams will b£r utilised. For the first time in New Zealand Peltcn wheels will be used in connection with tunnel construction. They will he operated upon by water, and will supply the power for hauling trucks, pumping air and water, operating the drills, and supplying electric current for lighting the tunnel. The Pelton wheel will ha worked by the projection of a powerful jet of water against a large number of small buckets attached to the wheel’s

periphery. The air percussion drill will belnsed instead oLthe hydraulic drill. It is thought 'to be the best drill for boring the |hard salty rock through which the tunnel will penetrate for most of its length.. It is expected that exceptionally heavy demands will be made on the supply of water power at the Bealey end of the tunnel. Water will probably accumulate in the workings as the tunnel slopes from that end, and a powerful pumping power will be required, as the water will naturally flow downwards to the opening. Probably about 750 horse-power will be required at the Otira end for all purposes. The tunnel, of course, will be bored from both evnds, the gangs meeting somewhere*near the middle. About two7miles and a quarter will be done from the Bealey end and about three miles from the Otira end.

The work of ventilation alone will be an important undertaking, and in this respect the contractors are “tied down to stated conditions'. Air, for instance, must be supplied at the working faces at the rate of 73 cubic feet per man per minute, where blasting operations are necessary, and 30 cubic feet where there are no blasting operations. Each horse used in the*tuunel will be given as much air as four men. With a complete plant of rock drills, boring steadily, many holes will be bored at one time, and there will be large blasting operations. The smoke and gases caused by these operations will be removed by exhaust tubes, and fine water sprays will be provided to absorb the gases. Although the specifications make provision in the case of horses being nsedif or haulage, it is likely that some form of mechanical traction will be adopted. The working and living conditions of the workmen receive considerable attention in the specifications. lAt each end of the tunnel, and at any winzes, or small shafts sunk for ventilation, which may be driven, the contractors will provide waiting-rooms, clofches-rooms, and bathrooms, which will be warmed as required, and will be furnished with a sufficient supply of hot and cold water. The accommodation : provided in this respect must be sufficient to meet the wants of ail the men in any incoming or outgoing shift, within half an hour after they reach the portal of the tunnel. Within one month of [starting the work on the tunnel these rooms must be completely finished and°equipped. Ambulance and first aid equipment must be kept, not only -at each portal, but at each working face. Outside the tunnel the contractors will house their men in huts, the sizes of which are in the specifications.