135

D.—l

through the Manawatu Gorge, and the slow rate of travelling from Tawa Fiat to Wellington, the time from Woodville to Wellington vid the Tauherenikau deviation would, I think, be a little shorter, as it also should be by the Woodside-Eoad Saddle route—in both cases for passenger-trains. The ruling gradient vid the Manawatu line against traffic to Wellington is 1 in 56, with 42-chain curves, as against 1 in 70 on the straight by the Tauherenikau deviation. I have endeavoured to condense into the attached table all the information available as to the costs as estimated and the salient features of the several routes. The costs given for hauling 100,000 tons of gross loads of goods-trains (i.e., the weight of wagons and their loads only, exclusive of the weights of the engines) from Woodside to the Upper Hutt, over the several routes, are computed on the supposition that engines of about the power of the new B engines will be run on the deviation, also that the gross weight of the trains up the 1 in 15, exclusive of the weights of the Fell engines and Fell brake-vans, is 110 tons. The average weight of the trains up the incline is, for the last year, just under 100 tons, so the comparison should not be unfair to the existing line. It would, however, be possible to get Fell engines capable of taking up greater loads; but, on the other hand, it would also be possible to get more powerful engines than the B engines, and I have no doubt by the time the deviation is made that such engines will be in use. The volume of the present traffic over the Eimutaka Incline is given in the attached memorandum from the General Manager of Eailways. The information regarding the Wainui-o-mata-Wairongomai route is hardly complete enough to enable any very definite comparisons being drawn between it and the other possible deviations between the Upper Hutt and Woodside. The estimated cost of this deviation is given by Mr. Dobson at £378,000, and is so high that the route will not at all compare with the Eoad SaddleFeatherston route, with equal grades 1 in 40, but for which the ascertained cost is only £181,200. In addition to this the distance would be ten miles longer. The great cost, the steep ruling grade, and the great extra length are, I think, quite sufficient to condemn this route. A considerable time will be required to make the permanent survey of the whole deviation from the Upper Hutt to Woodside—say, eighteen months to two years for a party as ordinarily constituted ; therefore, if anything is intended to be done in the near future, the survey should be put in hand soon. The first work to be done should, I think, be the running of a grade-line from the north end of the tunnel down the Tauherenikau to Woodside on the l-in-70 grade. This, with a sufficient number of cross-sections at suitable points, would enable the general character and amount of the works required to be approximately ascertained. Then a similar survey should be made from the east end of the Eoad Saddle Tunnel to Woodside. The limits of curvature should be 10-chains radius, except for the worst parts of the Tauherenikau, when 7-J-chain as well as 10-chain curves should, be tried. In the final location of the adopted line all grades on curves should be reduced to make the probable traction on each curve no worse than on the steepest grade on the straight. I think also that provision should be made for putting transition curves at the ends of all curves. As there is no very reliable information available for curveresistance on 3 ft. 6 in. gauge lines, I would recommend that some measurements of curve-resist-ance be made sufficiently numerous and accurate to enable the results to be used with confidence in all future railway locations. P. S. Hay.

PROPOSED DEVIATION, WELLINGTON-NAPIER RAILWAY, OVER RIMUTAKA. Summary of Leading Features of the Several Routes between Upper Hutt and Woodside Stations.

Boute. Ruling G] g , S •adients. § t s ? 3g.sa 3 . §538 " O I a Estimated Nui required foi 100,000 Tons of load from \ Upper Hutt, Haul I CO B0 <D -_ CD "i la! cnber of r Haulag Gross E Voodsid and Coe lage. Trains geof Qnginele to st of Lenj o Turn Rths >f nels. I ■a u oco -w to MO '5S-S III H x"S a 1 "3 ® a a a a OS [pper Hutt to Peatherston.uia No. 1 line and Road Saddle (1) 1 in 40+ 10-ohain curves 1 in 50 on straight (2) 1 in 34 on straight Miles. - 22| Ft. 1,585- £ 285,000 Trains 538 Trains 12,235 1,835 Yd. 3,146 Yd. I 440 . Ft. ■ 897 1 in 45 on straight 1 in 60 on straight 298,000 380 8,645 1,297 3,146 i 440 pper Hutt to Fernside, vid No. 1 line and Road Saddle 1 in 66 on straight 1 in 55 23 1,419 370,000 .287 6,601 990 3,120 l 440 + 500*1 897 , Upper Hutt to . Woodside, vid No. 1 line and Road Saddle 1 in 82 on straight 1 in 55 1 in 74 on straight 23J 1,279 460,000 235 f>, 464 820 3,100 ' 440 + 800" 897 pper Hutt to Woodside, vid No. 1 line and Tauherenikau 1 in 70 on straight 1 in 56 on straight ) 1 in j 60 J str. ( 1 in 64 on straight 1 in 53 on straight [ 324 (•272 j 338 6,120 918 [ to ] 1,650 J 440 + '< 800* 979 to 927 1,347 325,000 7,605 1,041 910 5,200 1,144 Ixisting line .. Iinl5+ 5-ohain curves 1 in 35 + 5-ehain 29| 2,485 •• curves * Assumed aggrei ite Iβ: igth of short tunnel*.