Construction
of the world's tallest railway bridge from the point of pillar height
has begun in Manipur by the Northeast Frontier Railway Construction
Organisation. The proposed bridge near Noney with pillar height up to
141 metres is slated to become the tallest in the world from the
point of pillar height surpassing the existing tallest of Mala-Rijeka
viaduct on Belgrade-Bar railway line in Europe where the height of
pillars is 139 metre, said an N-F Railway spokesman. The bridge in
Manipur is part of the 111 km-long Jiribam-Tupul-Imphal railway line
to connect the capital of Manipur with the broad gauge network of the
country, the spokesman said. The alignment of the railway line passes
through steep rolling hills of Patkai region, eastern trail of the
Himalayas, he said. While Jiribam, a small town of Manipur near
Assam-Manipur border, is situated 37 metres above mean sea level
(MSL), Imphal is situated at 780 metres above MSL. The alignment has
to traverse through not only a number of deep gorges but over several
rivers flowing at low ground levels necessitating construction of 46
tunnels measuring a total 54.5 km in length and tall bridges to
maintain a suitable gradient for efficient operation of railway, he
said. The longest tunnel will be 4.9 km long between Jiribam-Tupul
and 10.75 km between Tupul-Imphal section.
While
the high mountains are penetrated by constructing tunnels, the deep
river gorges between the mountain ridges are connected by tall
bridges. The tallest of such bridges near Noney spans over a gorge
with an overall length of about 700 metres, he said, adding, Railway
had constituted an expert group to study the possible alternative
span arrangements of such tall bridges considering parameters like
the length of span, type of span, location of the piers,
constructibility, serviceability, geological features, possible
tectonic movement. Based on the recommendations of the expert group,
it was decided that main superstructures will be steel open web
through type girders of 103.5 metre span (centre to centre of
bearings). The pillars are of reinforced cement concrete (RCC) hollow
type with the tallest pillar being 141 metre high, while the height
of other piers of this bridge vary from 50 metres to 90 metres. The
first phase of the project from Jiribam to Tupul (84 km), which
includes this bridge, is slated for completion by March 2016, the
spokesman said. An arch-type railway bridge under construction on
Chenab river in Jammu-Kashmir line bridging a gorge of about 360
metre depth from bed of river to the rail level is being considered
as the highest railway bridge in the world, he informed.
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