‘Persia – especially Seistan’ [‎94v] (187/949)

The mountain barrier overlooking Kech is apparently at its minimum of
height and width at the Kathag Pass. The ascent to the Kotal from the north
is short, and the height from the plain to the proposed tunnel mouth is only
300 feet. There will be some two miles of rather heavy earthwork among some
foot hills on the approach.
Through the summit at It. L. 2,600 or 2,650 a tunnel about } mile in
length is suggested, so as to clear the main range and some spurs that abut
on its southern slope. To shorten the length of the tunnel would entail prohi
bitively heavy works on the south approach. Prom the mouth of the tunnel
the line would develop at first among the foot hills and afterwards over a
broken glacis fissured with deep wide nullas. The glacis gets easier and the
ground less broken as the descent is made. After about 4 miles of expensive
development the line reaches easy country and descends to Rahgiwaran along
the natural slope of the glacis.
The ruling grade will be 1—50.
Two sections are plotted of the south approach of the pass, one running in a
south-east north-west direction, and the other in a north-east-south-west direction.
The first was hardly necessary, for it is obvious, ceteris paribus, that the natural
direction of development would be up the valley rather than down it.
At Kahgiwaran the Kil Kaur should be crossed, as it widens enormously
lower down. Thenceforward the alignment to Turbat is the same as that
a bead v described.
*
A good site for the bridge exists close to the camping ground where founds
on hard conglomerate will most likely be got close to the surface.
The banks are hard shingle and conglomerate 20 to 30 feet high, steep and
well defined. The waterway would be about 800 feet in 60 feet spans. There
is no surface flow in the river at Rahgiwaran, but there is at Oshaf three miles
higher up. Prom the size of the pools in the bed of the river and from other
circumstances I am inclined to think that the founds will require a lot of
pumping, for a tail race of ordinary length would hardly reach the rock, and
one would naturally expect a strong flow of water through the shingle.
The river when in flood evidently carries an enormous volume of water.
Its discharge in the recent floods cannot have been much less than the highest
recorded of the Nari, which has a catchment area many times larger. A? the
road crossing below the Tangi, I noticed that the water had been nearly level
with the banks there, 20 feet high and 800 feet apart. At Sami, where it is ^ a
mile wide, immense damage was done to the cultivated fringe on its right bank,
and the river bed was strewn with date trees.
Turbat to Tasni .—Prom Turbat two caravan roads lead to Pasni, one via
Pidark, and the other over the Gok Parosh Kotal, the scene of Major Mayne’s
victory over the Baluchis in the rising of 1897. I investigated both routes,
and the latter is undoubtedly the right one.
Considering the general elevation of the range, the pass is a remarkably
easy one. Its summit, B. L. 900, is only 350 feet above Turbat, 150 feet of
which takes the form of a gentle rise over a glacis.
The fall on the south side to the plain is only about 170 feet. A ruling
grade of 1—80 should be obtainable, but the works will be heavy for some
five miles among rough hills on both sides of the pass.
At the foot of the Kotal we are 52 miles from Pasni and only 700 feet above
sea level. The road thence runs for six miles in a south-easterly direction over a
stony plain intersected with a few shallow but well-defined nullas. It then
turns to the south through a short Tangi, and for the next 10 miles the works
will be average to heavy along the banks of the Samundari nulla. The
country is rugged with the usual chains of ridges.
Is ear Biloo Bandaf, between miles 28 and 31 from Turbat, the last and worst
of thf se is cleared : the road leaving the nulla and crossing a neck of ravines
which form the tail of the ridge.