NILGIRI
MOUNTAIN RAILWAY
 Asia's
steepest and longest metre gauge Mountain Railway is the Nilgiri Mountain
Railway (NMR) situated in the Nilgiri range of mountains. This mountain
railway covers a distance of 45.88 Km from Mettupalayam to Ooty with
the help of a unique rack and pinion system built specially to negotiate
the steep gradient of 1 in 12.28 (i.e. the train climbs up 1 foot for
every 12.28 feet of forward motion).
The route of this
mountain railway starts from the plains at Mettupalayam and negotiates
the steep gradient, passing through 16 tunnels many of which are unlined,
250 bridges and 216 curves to arrive at Udagamandalam (Ooty) situated
at an altitude of 7350 feet (2205 meters) above mean sea level.
In the year 1885 the
Nilgiri Railway Company was formed with a capital of Rs.25 lakhs and in
August 1891 the construction of the hill railway commenced. This metre
gauge hill railway line from Mettupalayam in the foothills of the Nilgiri
range to Coonoor situated at a height of 6000 feet (1800 metres) above
mean sea level was completed and opened for public traffic on 15th
June 1899. The line was later extended to Ooty from Coonoor in the year
1908 at the cost of Rs.24.4 lakhs.
 The
unique rack and pinion section (right) of this railway line extends from
Kallar and ends just a little distance before the Coonoor railway level
crossing. The average gradient on the rack and pinion section is 1 in
15. The rack rails consist of two toothed steel bars laid in a double
row 44mm apart and 64mm above the running rails so that the tooth of one
is directly opposite to the gap of the other to ensure that the engine
pinions do not work off the rack while negotiating the curves. The entry
to the rack is effected by a specially designed entry tongue laid in special
channel sleepers fitted with bow springs and connecting links which is
finally connected to the rigid bars.
The engines are always
attached in such a way that they push the coaches while going up (note
the LV or Last Vehicle board on the locomotive) and pull the coaches
while coming down. Each coach is provided with a brakeman who independently
operates the hand brakes and the rack brakes on whistle codes obtained
from the engine driver.
The 'X' class locomotive
used on this railway line are tank engines of '0-8-2' type with 4 cylinders
of compound type. The high-pressure cylinders work on the adhesion wheels
while the low-pressure cylinders working on the exhaust steam of the first
two cylinders work the rack system.
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For
Technical Details; & the Sound of the Steam Engine Chugging
Click Here
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