RAILWAY DEVIATION.

New Zealand Herald, Volume LXIV, Issue 19798, 19 November 1927, Page 8

RAILWAY DEVIATION.

MCKLAOT'S NEW OUTLET. iWORK AT WESTFIELD END, FINISHING ORAKEI TUNNEL. J GOOD PROGRESS RECORDED.

The part o! tha Westfield railway deviation furthest from the city has been snaking not less satisfactory progress than the work at this end. A gonoral survey of the BJ miles of route from the. Auckland station to Westfield station, where the deviation joins the Main Trunk line, leaves the impression of a very skilfully co-ordinated advance all along tha line. It 13 confidently expected that • all the major portions oi the wo:rk will be completed before the end of next March and formation will be sufficiently advanced to enable the laying of plates and rails then to bo commenced There are between 600 and 600 men always engaged on the job, many of them seasoned and expert workmen, and with the incentive of cooperative contracts and piece-work rates they turn out in the aggregate a very j big day's work The huge cutting at the northern approach to the Orakei tunnel is now almost completed. Of the 120,000 cubic yards it contained moro than 100,000 have been removed to make embankments, chiefly at Hobson Bay. Little remains now but to trim back the sides to the permanent hatter. From the Porewa end the top heading of the tunnel has now been driven in 930 ft. out of a total distance of 1930 ft. At the south end 600 ft. has been driven, leaving only 400 ft. yet to be done until the headings meet. The Purewa end heading is now almost underneath the St. Haliers* Ba.y Road at the point where there is a miximum height of 140 ft. of hill above the level of the rails. Very Severe Pressure. Tho pressure here is very severe and the nature of the country makes it necessary to exercise the greatest caution in driving forward. Explosives cannot be used at tho present time and every inch of' the heading has to be picked out. The massive character of the timber supports used is eloquent indication of the character of the pressure that has to ba withstood. When a visit was paid to the spot yesterday morning the gang at the face was engaged in manoeuvring into position one of the green kauri logs that form the essential part of the crown arch. Tfiese are 18in. logs, 19ft. in length, and are pushed ahead alongside the similar logs already in position, ready to take tho strain from them as the work advances. In the completed drive below the top /heading the walls are adorned with j thousands of glow worms, which entared the tunnel at the Purewa end and have gone on ahead of the concrete work, which is not to their liking. Unlike their kinsfolk at Waitomo, they seem to have , I no fear of sound. They have been brought up to the clash and clang of workmen's tools and explosives and they scorn to dim their lights when a stranger approaches. They came, apparently, from the bush-clad gully at the Purewa end and none are to be seen at the south end of the tunnel. Progress in the Tunnel. Both faces of the tunnel are now in dry country. The men at the south end, who had great difficulties to contend with at the commencement, are now in a very satisfactory piece of country, where the material is sand, permeated with scoria until it has almost become rock. Yesterday morning tho men were engaged on the interesting work of completing the top ol the concrete arch by filling it in horizontally from the front of the arch. The concrete is packed in to the depth of 2ft. 6in. As progress on the tunnel averages over 100 ft. a month, tho remaining 400 ft. should be completed during the latter part of March, allowing for tha Christmas holidays. From tho southern end of the tunnel jto the junction of the deviation with the main line at Westfield is a distance of miles. Of this two miles is now practically completed, and the remaining 2J miles is well in hand. The whole work is more than half done. Near tho temporary railhead a large quarry plant has been erected to supply the metal" required for roads, bridges, culverts and so forth. The crushers and elevator turn out large quantities of stone graded to the size required. Along the route of the railway the department has been fortunate in en- j countering stone of varying quality suited tc the differing" requirements of various parts of the work. An interesting record left by tbe volcanic forces of a bygone age is a perpendicular steam vent about lOin. across and very perfectly formed. It reaches from tbe scoria below right up through tho solid rock to the surface. Very Few Gaps Bemain. On the Klierslie-Paumure Itoad an overbridge and an extensive road deviation are almost half completed. The new railway continues by Mount Wellington, runni:ag parallel with the Mount Wellington highway. At the Waipuna Road crossing there is another massive overbridge in course oi completion. The concreting for the Mount Wellington highway overbridge is about one-third done. The country hereabouts is almost level and presents no engineering difficulties. Progress is being made on several sections of the route and the largest gap now remaining to be closed up is not mqre than 30 chains. To complete the main line formation there are three fairly large cuttings, each of which is about half finished. On this end of the line not much could be done during the past exceedingly wet winter, but since the ■weather became fine the work has been pushed on rapidly. A steam navvy is just now making excellent progress through swamp land where the Sylvia Park station will shortly be placed. Alongside this part of the line a most important new road, which will save a detour of quite a mile, is being put through from the Great South Road to the Mount Wellington highway. In addition to shortening a commonlyused route the new road will give access to the Sylvia Park station. The new line will cross the Great South Road practically at the road level and the formation of the approaches to the overbridge that will be required is now in hand. The* whole of this extensive work, under the direction of the resident engineer, Mr. R. H. Packwood, is being earned through well up to schedule .time, and it is gratifying to know that in a comparatively short time this new and beautiful approach to tho city will bo permanently opened up.