Bridge Refresher Topic 16 3 Callendar Hamilton span

Bridge Refresher Topic 16. 3 Callendar Hamilton span

Washout

Photograph of Bridge After opening to traffic

General • Temporary arrangements are structures used in lieu of the permanent bridges structure to ensure uninterrupted traffic • They are designed as simple and light weight structures so as to be handled easily during erection and ensure faster speed of constructions • Callender Hamilton Span is used for restoration works for longer spans (more than 24. 4 m).

Callender Hamilton span • The Callender-Hamilton bridge is a modular portable prefabricated truss bridge. It is primarily designed for use as permanent civil bridging as well as for emergency bridge replacement and for construction by military engineering units. Assembling a Callender-Hamilton bridge takes much longer than the more familiar Bailey bridge as it is made up of individual lengths of galvanised steel bolted together with galvanised high-strength steel bolts, all of which require torque settings. It is stronger and simpler in design concept than the Bailey bridge.

CH Span History • The Callender-Hamilton bridge system was designed by the New Zealand civil engineer, A. M. Hamilton, and patented by him in 1935. The system is currently fabricated by Painter Brothers, Hereford, operating within the Balfour Beatty Power Networks Division[1] formerly British Insulated Callender's Cables. • Hamilton's bridge concept was inspired by his work between 1928 and 1932 as principal engineer on the 'Hamilton Road' through Iraqi Kurdistan. He described the building of this road in his book, Road Through Kurdistan: Travels in Northern Iraq, 1937. Hamilton became aware of the need for strong, adaptable bridges made from simple components that could easily be transported and erected in remote locations or on difficult terrain.

CH Span Design • The Callender-Hamilton bridge system is a prefabricated Panel/Floor Beam/Deck system designed to span bridging lengths ranging from 30 to 150 metres with road widths of one to three or more lanes. The design uses Warren trusses and is centred on a series of gusset plates that allow the direct attachment of the longitudinal, diagonal, vertical, and cross framing members. Centralised connection points increase the speed of construction and allow identical panels to be fabricated from identical members and then installed on site. An important feature is that all connections are bolted, so removing the need for onsite welding.

CH Span Design • The bridge is usually built on falsework. A reinforced concrete deck is then superimposed on, and acts compositely with, the fabricated steel truss deck, thereby eliminating the use of scaffolding. A steel orthotropic deck, steel open grate deck or a timber deck are alternatives to a concrete deck. As with the Bailey bridge, an enhanced feature of the Callender-Hamilton bridge is that it can be assembled entirely on one side of a gap and with a removable launching nose added then be projected on rollers to the other side. [3] • All bridge elements are small enough to be transported by road and site operations can be carried out without skilled labour, special plant or heavy equipment. Because of the modular design, repairs are as structurally efficient as the original construction and at the end of service dismantled bridges can be reduced to initial components for reuse. Salvability is high due to the hot-dip galvanisation of each individual component.

CH Span Connections

CH Span Connections

CH Span Examples • • • • Bridge No 194 in KZJ-BPQ Section, South Central Railway, India Caparmesnil near St-Pierre-sur-Dives, Normandy Cleenish Island Road County Fermanagh, Northern Ireland Grand Falls - Province of Newfoundland Labrador Heusdensch Canal Netherlands Langwathby Bridge, Cumbria St. Lewis and Alexis Rivers, Province of Newfoundland Labrador Tal-y-Cafn type B 10 bridge over the River Conwy Two Fords Bridge Lydlinch, Dorset Two Lane Bridge at St. Paul's Bay - Province of Newfoundland Labrador Vernon, Eure, Normandy, between 1945 and 1955. Walton Bridge Fourth Bridge Pont du Mandrare, Anosy, Madagascar [14] between 1958 and 2012. Axminster, Somerset - A temporary Callender-Hamilton bridge has been constructed over the River Axe adjacent to the M 5 to facilitate construction works for the Hinkley C Nuclear Power Station power grid connection

Callender Hamilton span: In Indian Railways • Designed for purpose of building long spans (above 24. 4 m) as rapidly as possible in place of steel span in case of emergency • Panel fabricated of length 10’-4” • These girders are of warren type truss with double intersection for span 24. 4 m and 30. 5 m • The chord members as well as web members are made up of angles 8”x 1/2” (high tensile steel)

Callender Hamilton span: In Indian Railways • Main gussets are made with 1” thick plate • Member to gussets connections at panel points are with 2” dia turned bolt (high tensile steel) • Bearing are provided with flat type for 18. 3 and 24. 4 m and knuckle pin type for span above 30. 5 m • These girders are available with N. Rly, NE, C, NF & E. Rly. • A hand book containing details is available for using the span properly • Slightly heavier spans, also called US spans, available with NF Rly. • All the members of CH span can be transported to site by BFRs/ Wagons and Span is assembled at site.

Callender Hamilton span: In Indian Railways • Erection of these spans normally carried out on any one side and it is rolled in position with the help of skids and launching pad. • 200 men are required for 8 days to work in 3 shifts for assembly and launching of one 30. 5 span • Precautions while launching – Cribs should be checked for stability – Bolts and nuts should be tightened properly – Jacking points should always be on panel points

CH span being pulled 2 ft 15’-6” 2 ft

Erection of CH span in progress

Photograph of erection of UC span

Photograph of Launching of UC span

Train on CH span (semi through)

Photograph of Bridge After opening to traffic

Thanks