Howrah, a busiest bridge in India
The end of the 17th Century Kolkata witnessed the gradual emergence
of the city of Kolkata brought about by the merger of three villages - Kolkata,
Sutanati & Gobindapur,
on the eastern bank of the river Hooghly, the other name
of River 'Ganga'. On the western bank, Howrah came up as a bustling site of commerce.
The twin cities of Kolkata and Howrah, were separated by the River Hooghly, and
shared a common historical linkage towards the eventual construction of the Rabindra
Setu, more commonly known as Howrah bridge. While Kolkata, from a small sleeping
hamlet of artisans and mercantile community eventually developed, as a commercial
hub of a modern metropolitan city, Howrah (virtually the store house of raw material
resources) became its industrial satellite.
For the convenient plying of passenger and vehicular traffic, the pool was connected
as a whole. However, this was unfastened every day, particularly during the night
for safe passage of steamers, boats and other marine vehicles. From 19th August,
1879, the bridge was illuminated by fixing electric poles at the centre. The Bridge
was then 1528 ft. long and 62 ft. wide. On both sides were pavements 7 Feet wide
for the sake of pedestrians. The 48 ft. road in between, was for plying of traffic."
The present Howrah Bridge, renamed as Rabindra Setu in the year 1965, after Rabindranath
Tagore, the philosopher - bard and one of the most important nineteenth century
renaissance personalities to leave a lasting impression on modern India.
Technical Parameters
Rabindra Setu is a suspension type balanced cantilever bridge with central span1500
ft. between centers of main towers. The Anchor arms are 325ft. and the Cantilever
arms are 468 ft. long at both ends. While the middle suspended span is 564 ft.,
main towers are 280 ft. high above the monoliths and 76 ft. apart at the top Bridge
deck width is 71 ft. with two footpaths of 15 ft. on either side. All members of
the super structure comprise built-up reverted sections with a combination of high
tensile and mild steel. Between towers, bridge deck hangs from panel points in the
lower chord of the main trusses with a series of hangers (39 pairs). Roadway beyond
the towers is supported on ground leaving anchor arm free from deck loads. Bridge
deck comprises 71 ft. carriageway and 15 ft. footway, projecting either side of
the trusses and braced by longitudinal facia girder.
Brief Details
- Bridge type : Suspension type Balanced Cantilever
- Central span 1500 ft between centers of main towers
- Anchor arm 325ft each
- Cantilever arm 468ft each
- Suspended span 564ft
- Main towers are 280ft high above the monoliths and 76 ft apart
at the top
- Bridge deck width 71 ft with two footpaths of 15 ft either side
- All members of the super structure comprise built up riveted sections
with a combination of high tensile and mild steel
- Between towers bridge deck hangs from panel points in the lower
chord of the main trusses with a series of hungers(39 pairs)
- Road way beyond the tower is supported on ground leaving anchor
arm free from deck loads
- Bridge deck comprises 71 ft carriage way and 15 ft footway projecting
either side of the trusses and braced by a longitudinal fascia girder.
- The deck system consists of cross girders hung between pairs of
hungers with pinned connection.
- Six rows of longitudinal stringer girders span between cross
girder.
- Floor joists supported transversely on top of stringers.
- They support a continuous pressed steel troughing system.
- Over which deck concrete is laid out.
Expansion Joints
- Longitudinal expansion and lateral sway movement of the deck are
taken care of by expansion and articulation joints.
- There are two main expansion joints, one at each interface between
the suspended span and the cantilever arms.
- There are expansion joints at the towers and at the interface
of steel and concrete structures at both approach.
Foundation
- The main tower is founded with single monoliths which are 55.31
x 24.8 m in plan with 21 chambers
- Monoliths at Calcutta and Howrah side are founded 31.41 m
and 26.53 m in below ground level respectively.
- Minimum headroom in carriageway is 5.8 m
- Freeboard for river traffic is 8.8 m
Vidya Sagar Setu –The Twin
With the phenomenal increase in city traffic and to partially
release the pressures of the Rabinda Setu, the largest cable stayed bridge
(in Asia) over the River Hooghly was constructed by a consortium of Indian P.S.U.
and private firm under the consultancy of S&P Germany & FFP of UK. The Bridge
was commissioned in the year 1992 under the aegis of Hooghly River Bridge Commissioners.
This bridge was christened "Vidya Sagar Setu", after the country's greatest educationist-reformer
and freedom fighter, Pandit Ishwar Chandra Vidya Sagar.