‘Persia – especially Seistan’ [‎90v] (179/949)

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16
line could reach the Kotal hy a shorter route than the right-angled bend along
which the section was taken.
At the foot of the Kotal, at the point A on the section, is a small plain of
sandstone on edge forming a cup among the mountains, and a certain amount
of development can he done round the sides of this hollow. At its eastern
extremity are the headwaters of the Sir Kaur (east). The section follows the
nulla for five miles till further progress is stopped hy a lake formed by slips from
the ends of a high range of shale hills that crosses the nulla at right angles.
Up to this point the alignment, though very expensive, has not been impossible,
hut the sides of the lake and the slips beyond are quite impracticable. The
alignment should, therefore, after following the nulla for 2 ^ miles, trend to the
right and tunnel through the clay ridge with a tunnel probably miles long.
The rest of the descent is easy. The outer range of sandstone, which runs
parallel to the clay shale ridge, and about i mile east of it, can be turned at
the debouchement of the Sir Kaur into the plain.
An alternative to this would be to tunnel through the clay ridge on the
north side of the nulla, but the point is immaterial. 1—45 will be the best
gradient that can be expected on this Ghat. 1—40 will be satisfactory.
This bit of reconnaissance was the most trying work, as it had all to be
done on foot, and the month was June. So precipitous and smooth is the clay
ridge that it was impossible to get any measurement over it, its sides appeared
quite unclimbable without some sort of paths; but from opposite ends of the
lake a good idea of its width was obtainable, and I believe .my estimate of H
miles of tunnel is liberal. The Trignometrical Survey maps, which, east of Seetaro,
are on a scale of 2 miles = 1 " and on the whole very accurate, support this
conclusion. Unfortunately any one unacquainted with the country will
hardly be able to distinguish this important clay ridge on the map, possibly owing
to its top and sides being a multitude of little cones, and in showing the cones
the fact that, in the aggregate they form a range, has been overlooked. It is
also shown further from the outer range than is really the case.
I need scarcely say that the detailed surveys from the Kotal downwards
will be exceedingly difficult and arduous from the inaccessible nature of the
hills. A raft or Berthon boat will be of great assistance.on the lake, which is
nearly * mile long but very narrow. None of us liked swimming it for fear of
crocodiles (though there were no signs of them on the bank), and so we had to
make a circuit of more than twenty miles to get to the opposite end, for the
hanks were too steep and friable to clamber along.
[Ar _Z2.—It will be observed that the large tracing on the scale of 4 miles=
1 " only shows the hills bordering on the proposed alignment from the Sir Kaur
to Karachi. The reason is that these few sheets.are only published on a scale of
2 miles=l", and to reduce them to the 4 miles=l" scale would have taken
months. Printed sheets, on the 2 milesr^l" scale, are, however, enclosed for
reference.]
The works on this Ghat will undoubtedly be very heavy. At the same time
a little consideration will show that Bela is one of the most convenient places
on the line for heavy works to be situated. The rails can reach the mouth of
the tunnel from Karachi in a single year, bringing tunnelling plant, construc
tion materials, and an ample supply of labour. While the tunnelling works
are in progress, the formation can be completed up to Jhau, so that by the
time the tunnel is complete there will be an uninterrupted stretch of line ready
for the rails as far as the Nal Biver, while the Jhau-Kolwa Section should also
be well in hand. It may be added that the clay shales and soft sandstone on
the Ghat are very suitable materials for tunnelling through, and that, with the
exception of the slips forming the bund of the lake, (where the cliffs were
so sheer and high that slips were bound to occur), there were no. genuine slips
in the country; nothing but occasional falls from overhanging cliffs.
Alignments from Bela to Karachi- —At the entrance of the Sir Kaur
into the Bela plain, 126 miles from Karachi, all difficulties of construction
cease. Thence, till we approach the low plateau forming the tail of the
Habb Mountains, the line is over alluvial country, once, no doubt, an arm of
the sea.
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