Bridge Details
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
Other features of the Bridge
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.
More about the Bridge
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.
Joint System of Bridge (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.
Articulation Joints
There are total 8 articulation joints.
3 at each of the cantilever arms.
2 in the suspended portions.
They divide the bridge into segments with vertical pin connection between them to facilitate rotational movements of the deck.
Camber and Traffic clearance
Bridge deck has longitudinal ruling gradient of 1 in 40 from either end
They are joined by a vertical curve of radius 4000 ft.
Cross gradient of deck is 1 in 48 between kerbs and central 4.9mtr. is level to provide tramway housing channel in between troughing.
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