58 
Indian Forest Records. 
[Vol. VI 
6 inches high, from the ground, on which slides a beam at right angles to 
the rails and therefore parallel to and above the tanks, filled with flat 
iron plates. To the centre of the beam are attached two simple wooden 
pulleys, about 3 feet apart ; to raise a parcel of sleepers, two ropes, one 
over each pulley, are hooked to the chains round the sleepers, and as 
the parcel of sleepers is raised out of the tank, two small poles or bars are 
put at right angles across the tank and the parcel allowed to rest on them 
until it is broken up and the sleepers removed. In the same way the 
sleepers to be treated are made up into lots over the tank, then bound 
and lowered into the solution. After having dealt with the sleepers 
for one tank, the bar is pushed over the next tank and the same operation 
repeated. 
Such a type of plant is very convenient for treating a- few sleepers 
for experimental purposes. With an immersion period of, say, ten hours, 
the four small tanks can deal with about 48 sleepers a day or 1,200 a 
month. Were the work to be carried out on a larger scale, it would be 
necessary to raise the travelling bar to 5 feet above the ground in order 
to permit of differential, instead of simple pulleys, being used and to 
have larger tanks of, say, 6 feet 4 inches long by 5 feet broad and 2 feet 
8 inches deep, taking two parcels of 9 sleepers each or 18 per tank. 
Working with an immersion period of 10 hours and with 10 tanks in 
use, the number of sleepers which could be dealt with daily would amount 
to 360, say, 9,000 a month or 100,000 sleepers a year. 
The difficulty experienced in sinking the Pine sleepers was not ex¬ 
perienced when dealing with the Dip'erocarp sleepers, as their specific 
gravity is higher than that of the Pine woods, so that a bit of old rail 
was found to be quite sufficient for the purpose. 
The treatment of the sleepers was carried out as follows :— 
As soon as the oil reached a temperature of about 70°C., the sleepers 
were put in and allowed to remain in the hot oil at a temperature vary¬ 
ing from 75°C. to 90°C. for an hour. At the end of that time the fires 
were drawn and the sleepers allowed to remain in the oil for another hour 
while the liquid cooled down. As the work of treating the sleepers 
was in progress, a number of sleepers were weighed before and after treat¬ 
ment with the result that 72 Dipterocarpus alatus and 168 D. 
tuberculatus metre-gauge sleepers absorbed Ml lbs. of the oil each. 
It is probable that this is not a sufficient quantity of oil to protect the 
timber, so that a longer period of soaking would have been advisable. 
Tn order to ascertain the quantity of oil this species of timber will 
absorb, 4 sleepers were treated for an hour in the hot oil and then 
allowed to remain in the oil for 19 hours as it cooled down. These 
sleepers absorbed 9-4 lbs. each or, roughly, 6 lbs. per cubic foot. 
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