Recent Completed Projects
Please follow the links below for further details of each project.
 |
£6.5m replacement of a 4 span overbridge |
 |
£13m reconstruction of the superstructure on a 49 span viaduct |
 |
£3.5m reconstruction of the superstructure of two underbridges |
Kilburn High Road
Network Rail were responsible for the design and construction of a £6.5m project with Galliford Try to replace a four span overbridge, at Kilburn High Road in North London, which is owned by Network Rail. The structure carries the A5 over the West Coast Main Line railway, at this point the A5 is the direct arterial route from Marble Arch in central London to the start of the M1 motorway.
The bridge comprised three spans of cast iron beams dating from the 1850's and a fourth more recent span of steel construction. The three cast iron spans failed their Bridgeguard 3 assessment and needed replacing in order to carry modern 40 and 44 tonne HGV traffic. The fourth span required strengthening. The road bridge was the central one of three. The adjacent parallel bridges carry footways, shops and Kilburn High Road station, meaning that access to the site was extremely restricted.
The scheme to replace the bridge was further complicated by the presence of a large number of utility pipes and cables. In particular two 450mm diameter gas pipes, two 450mm diameter and one 300mm diameter water pipes and over 50 BT ducts had to be temporarily diverted or worked around.
The planning and sequencing of the works were crucial to the success of the project which had to be completed whilst minimising disruption to vehicle and pedestrian movements. Through detailed liaison and planning with Camden Council and Transport for London, Network Rail was able to devise a scheme that saw the bridge replaced with modern precast concrete units over a 106 hour possession of the railway using a 500 Tonne crane at each end of the bridge and a third service crane.
The overall cost of the scheme was £6.5 million which included £2 million of service diversion costs. At the height of the possession weekend there were around 100 engineers on site and approximately 1,500 m3 of debris was removed from site. The project was a logistical success and saw a large bridge carrying one of the busiest roads in London over the busiest mainline railway completed on time and to budget.
During the main weekend, temporary bridges, 45m long were used to support some of the BT cables in-situ and hence reduce the cost of diverting them. Pedestrian access around the site was maintained at all times through careful planning and shops and premises remained open throughout.
The possession was handed back 30 minutes early and the eight week road closure was given up one day early.
Leven Viaduct
Network Rail were responsible for the design and construction of a £13.0m competitively tendered project with Carillion to reconstruct the superstructure on a 49 span viaduct. The viaduct is located on the Carnforth to Barrow-in-Furness Railway Line near Ulverston, in the South of the Lake District. The rail line is a strategic route for nuclear trains to Sellafield and an important long distance passenger and freight service route to Manchester and trans- Pennine.
The 49 span,480 metre viaduct was originally constructed in 1848 and reconstructed in wrought iron in 1880. The viaduct was assessed as approaching the end of its serviceable life and a speed restriction was imposed. Route strategy analysis concluded that allowing the condition of the asset to deteriorate and the imposition of weight restrictions and a further reduction in speed would significantly affect the operating capacity of alternative rail routes and would increase road traffic.
The viaduct crosses Leven Estuary which feeds into Morecambe Bay and is included within the limits of the Site of Special Scientific Interest, RAMSAR, Special Conservation Area and protected bird areas. These environmental restrictions prevented any access to the viaduct from the estuary bed and effectively reduced the allowable working to the width of the viaduct.
Extensive planning and consultation with the train operating companies and local authorities allowed the railway to be closed for 16 weeks to enable the reconstruction of 48 decks with new steel units whilst span 37, the original shipping channel, was strengthened and refurbished to meet current design loading requirements. A further consideration was the relocation of three 11kV power cables which were located along the full length of the viaduct.
The logistics of the site and the constraints led to an innovative approach whereby the demolition and reconstruction made extensive use of mobile gantries, which allowed the demolition and construction activities to run concurrently.
Site access for all major plant and equipment was located three miles away in each direction at Cark and Ulverston stations. The environmental and geographical considerations led to satellite worksites being established and managed.
A 125 strong workforce was employed for the 16 week long blockade which involved the fabrication and erection of 3500 tonnes of new steelwork and over 1km of new railway tracks. All works were successfully complete within the blockade, safely and within budget. The viaduct was handed back into operational service on time despite delays at the start of the project due to adverse weather and mechanical failures.
All works were successfully complete within the blockade, safely and within budget. The viaduct was handed back into operational service on time despite delays at the start of the project due to adverse weather and mechanical failures.
Clapham Junction
Network Rail was responsible for the design and construction of a £3.5m project with Edmund Nuttall Ltd to reconstruct the superstructure of two underbridges, between Vauxhall and Clapham Junction Stations. The extensive engineering work at Clapham Junction included the reconstruction of a 100 year old rail bridge.
The bridges carry all tracks of the Brighton Main lines between Battersea Park and Clapham Junction, together with all tracks of the Bournemouth Main line, the Windsor lines and a siding between Queenstown Road and Clapham Junction. The bridge decks were single span structures, with main and cross girders of riveted metal, built up section, supporting longitudinal timbered track.
Extensive planning and consultation with the train operating companies and local authorities allowed the railway to be closed for 100 hours over the Easter Weekend in 2004.
The work involved two of Britain's largest rail cranes which removed the existing Victorian, steel girded bridge and lifted in new prefabricated steel composite bridge decks.
- 10 Bridge decks replaced in 101 hours
- Lines to Waterloo and Victoria open to traffic on both sides of the worksite
- 60 tonnes of track timbers removed
- 220 tonnes of brickwork removed
- 360 tonnes of new steel deck
- 200 tonnes of pre-cast concrete installed
- 16 Engineering trains involved
- Two Kirow Cranes required for the job
- Over 1300 site shift briefings given during the main weekend.
The attention to detail and planning of this complex operation ensured that all works were successfully complete within the blockade - safely and within budget – and the bridge was handed back into operational service on time. The project delivered a new structure with a design life in excess of 100 years, providing a more reliable railway on one of the busiest routes into the capital.