MB. PARK'S REPORT ON BROWNING'S PASS.

Lyttelton Times, Volume XXIV, Issue 1485, 14 September 1865, Page 6

MB. PARK'S REPORT ON BROWNING'S PASS.

Ashburton, August 28th, 1865. Sir,—ln accordance with instructions contained in your letter of the 3rd July, 1865, requesting me to examine, lay off, and repo-t upon part of a line of road to the West Coat at the North llakaia pass, I have the honor to report as follows :— That, after considerable delay, in co - sequence of snow upon the face of the hi if, and general inclemency of weather, I at last succeeded in reaching the top of the hill, and examining the features of the ground from the south to the north face of the pass. That I find there will be very little difficulty in cutting a track for stock up the south face and down the north, with very fair gradients ; and that should the Government determine eventually to form a dray road, that can also be accomplished at not a very great cost. That there is feed for stock right up to the foot of the hill, even at this season ; and

Mr, Browning informs me that there is grass on the face and top of the hill, now, of course, under snow. The snow lies from three to four feet on the sides and top, and on lake Browning, and I suspect will remain for two months longer at nearly the same depth ; but were the road once formed, stock could travel at this time of year by clearing away the snow, either by manual labour or by the snow plough. The snow has never fallen to a greater depth at one time than from a foot to eighteen inches since I have been on the spot, and we have experienced very severe weather, generally commencing with rain, then sleet, and ending with snow ; the surface then freezing formed a crust for the next fall to rest upon, until the accumulation became three or four feet. It is plain, however, that were there sufficient traffic on the line, the road could always be kept open. The snow, when I left, only extended about three miles on either side of the pass. The read by its windings stretches to a distance of about two and three-quarter miles; but the only part requiring to be cleared would be the faces, say about one mile and a half; stock would not now sink more than six inches to a foot on the summit. After several attempts to reach the top, by cutting a traverse through the enow, I was obliged to abandon that method, and walk straight up the face, we digging our toes into the snow. But when Mr. Browning and party left, they having heavy packs to carry, we found it necessary to dig steps in places; it took from an hour and a half to two hours to reach the top, but only a quarter to return, as we found sliding down the easiest mode of descent. When unable to face the hill, the men were employed in erecting a comfortable hut, 26 feet by 13 feet, containing two rooms, one 10 feet long, as an eating and sleeping apartment, lined with canvas, and having eight bunks therein, with chimney, table, &c.; the other is used as a store-room; the sides are of split totara, and the roof covered with two tarpaulins. This hut is about a mile from the foot of the pass. We could not get splitting stuff nearer, and it would have taken too much time and labour to have carried the slabs up to the foot. While the men were thus employed Mr. Browning made a survey of the valley from Sebastopol to the waterfall. I shall now proceed to give a somewhat detailed report upon the Toad, referring you to the accompanying maps and profile of hill for the purpose of elucidating the same. No. 1 is a tracing from Mr. Browning's map of the valley and pass, an actual survey as far as the north face, the remaining portion of the wooded saddle being from recollection of former sketch survey. No. 2. An enlarged map of the pass alone. No. 3. Profile and sketch of hill, as accurately laid down as I could accomplish. Keferring to Nos. 2 and 3 (to both of which the same letters and lines apply), I commenced work by running the yellow line from the boulders (marked on plan), intending to reach the summit by that course, when, after getting as far as the rocks, Mr. Browning, who was in advance of the party, slipped upon the frozen snow, and went down on his back some •*OO feet, at an angle of about 35 deg., luckily reaching the bottom unhurt. Afraid of risking the men further in this direction, the rocks being coated with ice, I spent some days further in traversing up the hill to B, when, sleet and snow coming on, and lasting three to four days, filled up all our work. Afterwards the weather was so bad at intervals, that I found it utterly useless to attempt work that might be obliterated next day. I therefore set the men to work upon the hut. The scheme I propose for the road is shown by a red line, commencing at A near the waterfall, and at about the same level as the boulders (marked on map, and taken as 2300 feet above the sea). From that point, with a gradient of one in five, and a distance of some 55 chains, I reach the rocks at B, about 726 feet of rise. From B, rock cutting will commence, and as far as C I hope to get a gradient from 1 in 9 to 1 in 12, the distance being some 25 chains. About 15 chains of this will be through rock, a clay slate on edge, a portion of which may be removed with the crow-bar and pick, harder rock by blasting; but, from the impossibility of reaching those rocks for examination, I cannot speak correctly as to their character. Should Mr. Greenlaw, in cutting his tracking, find much difficulty with the rock. I have instructed

him to traverse up the hill, as shown by the red dotted line. Stock could travel up this slight benching in the spring, thus leaving time for the rock work.

I wish to cut the rock at an easy gradient, on a line that, by widening, will suit for dray traffic if required. By looking at the maps you will see that I have pencilled a track up the eastern stream that would suit such purpose. From C to D, the level of the lake, and over summit, one in nine will be obtained, with a short cutting of about six feet, near the margin of the lake. The length of this portion will be, say, 20 chains. I make this summit (the surface of the lake) about 1050 feet above the starting point, and 150 below the gap on the hill, 1200 feet in nil from the boulders to gap. This height is from a mean of four observations of the aneroid. I think it near the mark, as, by an observation with a pocket sextant, the height of the hill at gap from the boulders was 1300 feet. My base, however, was not good ; I hnd no artificial horizon, and had to get the level from an instrument not adapted to the purpose. I therefore hold to the former heights. From lake Browning to the north face stock might travel without any or very little cutting work. I shew on the map the line as laid down by Mr. Browning, with the appropriate grades.

Thus, for ftbout 20 chains to E, the line would be neirly level, another 25 chains to F

at about 1 in 8, and the remaining 25 chains to G, at about 1 in 4 to 1 in 4J. The red dotted lines are to be examined by Mr. Greenlaw, and reported on, as likely to give an easier grade if not too expensive. I now proceed to quote Mr. Browning's report to me on the line from lake Browning (at D) to the wooded sad lie, as I went no furiher than the north face, I shew a gradient from the top of the north face to where that road is proposed to cross the Taipo, my data being that the foot of the north face is about the same level ns

that on the south, and the fall to the Taipo crossing 100 feet from foot of precipice, lhis I think near enough for the present purpose, there being no doubt that stock could descend along the face of the hill, were the snow off the ground, or a benching cut, and Avould turn down from the stream coining from Mount Harman to the Taipo. Mr. Browning states—On rounding the spur over the waterfall, the road would follow

(from D.) on a dead level, on the western side of lake Browning, crossing the head of a small gully antt sideling along the downs, as shown on the plan, until a point is reached on the Taipo (G), where the gorge becomes shallow, through which the overflow from the ltike pusses ; here a cutting would be required about 6 or 10 feet deep, and the stream, which is very small, crossed on the level on rocky bottom. A sharp rocky spur from Mount Hnnnan here runs down to the creek, and requires, probably, three to four yards of rock cutting.

"Prom this spur ike road wo*ld descend

in a practicable gradient to n,„ river, crossing it about half aLi , T «ipo north face of the pass. On tS ?• m °>e four or fire chains from thrf ' ab °ut hill side is of the fiame nature T*' the southern face of the pass- .1 0n the of the half-mile traverser! b y the g Z, fIBO ?"? Btone - The downs on i 18 0n side of the saddle terminate in a "l, r " orth pice (the north face), several V T prf:ciabove the rocky bed of the Tair,, , 1 fe <* or two below the point (G) where? Chain crosses the overflow of the lake r,)a( i 'From the lower crossing of Mie T., ; point on the terraces above thr/ L p,) to a tance of about half-mile the r 7f' a ,!iaeasiiy taken, and continued on the™" be flats to the point at the junction Harman stream with the Taino i the bridge will be required, ettim.L I ? a Cahiil to be about fifty feet snan t ! )y rza S « probably bc ISS ; J'• rfggrant. and a copple o[ ITIX , l ajl | *' J' 1 « foot passengers. oss f op " On the north side of the Harman th. I n side, which is gras«y, slopes down i t? • bed, for a short distance, up which l, r ! Vtr track could be taken at a practical.!?' i ' ng till a point i, reached 'StU menceg, Iron, here the t,„k round a spur of the range to tl / L \ the second or wooded saddle which • of little lower, a dtaance „i ,2, " ' and a half miles tl,rough hill side is probably of the sn.if.? as that of the other side of 'the T • e SSi"» " iU ' large it then appears that all the difficulty n K in rising the south face and J.l* north, the top being nearly level f or t chains; the remaining 50 chains, only , tH X places requires little or no work, and it ' provable by better gradients. The ascent on the south face, 100 chains imhL quarter ' with a totalrise "f The descent from the top of the precipice to the lower crossing of the Taipo i, at ' 55 chains, with a fall of, say, 660 feet On the whole distance. I do not anticipate more than 20 chains of rock cutUn* • ft r gradients for a stock road, and elbow-room 1 work out better ones for a dray road An 1 besides, by tunnelling the hill from a mii o t d a mile and a-quarter through, a railway mav be constructed from Christchurch tolioki tika. l "

With regard to the cost of forming a sir foot track, I feel rather diffident in giving a " opinion, so many items require consideration such as price of labour, transit of plant and supplies, the uncertainty with regard to the nature of the rock, &c., &c. But, assuming that four feet cut out of the solid will be sufficient to give a firm six-foot of road taking the inner slope of cutting at one in one (about all to be got, as the slope of the hill to be traversed is from 24 c to 32 =. and although I am aware that one in one is too steep in shingle cutting, yet it cannot well be improved, and slips must therefore be remove 1 as they occur) ; the result is, say, one and three-quarter cubic yards to one lineal vard, or some 3000 cubic yards among sLiirMe and earth cutting, and of course something less for rock, as it will stand nearlv perpendicular. (There will be no wheeling) I leave to the Engineer's office the decision as to value, strongly recommending that the work should be let by contract. Mr. Greenlaw commences benching out the red line whenever it is possible to work on the hill,and in themeantimeis clearing a track to the foot of the pass for the more easy passage of pack horses. A bullock dray would have very little trouble in reaching the foot of the hill even now. Your obedient servant, Robert Park, To the Secretary of Public Works.