Blackfriars Station is currently visited by more than 44,000 people every day and as part of the Thames Link Project initiated by Network Rail and First Capital Connect an improvement scheme was undertaken at the Station to increase its capacity from 12 to 24 trains an hour and provide an improved link with Blackfriars Underground station.
In order to facilitate the scheme at Blackfriars Station Northside the works carried out by Keltbray consisted of multiple complex demolition interfaces and groundworks in and around the live operational rail station. The station remained live throughout the works.
In addition to maintaining the station live with a large daily throughput of passengers the worksite was bisected North/South by the LUL District and Circle Line. Although the underground station was closed trains continued to run through the worksite within a temporary protected tunnel structure.
The demolition works included the removal of the existing Network Rail station including the roof, platforms, track structure, abutments and superstructure in conjunction with the removal of the existing LUL ticket hall structure directly over the temporary tunnel structure and the removal of the existing building over the live railway. This latter structure included the removal of a 200 tonne Vierendeel girder and 2No.60m trusses over the River Thames.
The groundworks package included the design and installation of a propped temporary ‘king post’ wall and specialist piling decks to facilitate the secant piling works and basement works which required the design of two strutted secant piled excavations which extended 4 metres below the LUL platforms. These excavations incorporated temporary bridges for access.
All temporary works solutions employed on the project were designed in-house by Wentworth House.
Project Challenge and SolutionsNetwork Rail Approvals – early liaison and workshopping with the Balfour Beatty and Network Rail teams with the aid of 3D modelling technology in order to explore value engineering and sequencing efficiencies ensured that Works Package Plans and Form C sign offs for the works methodology and temporary works engineering solutions were completed within the required programme timescales. Maintaining Stations Live throughout the works – Due to the sheer volume of passengers using the station during the week much of the work was carried out during weekend and night time possessions of the railway. During a single possession over Christmas 2009 4 No. track decks and over 200 tonnes of heavy girders were successfully removed using 2 No. 450 tonne cranes. These works were carried out with very tight programme constraints as Balfour Beatty and Network Rail had to carry out the new bridge slide operation during the same possession following our enabling works. A further weekend possession in February 2011 saw the removal of an existing 70 tonne Vierendeel steel girder which formed part of the original station roof. This was removed following the culmination of months of pre-planning and workshopping across Keltbray demolition and civils division, in-house temporary works engineers (Wentworth House Partnership), Keltbray Plant and Keltbray Rail. Site Logistics – the site was accessed from heavily trafficked adjoining roads. Careful adherence to the Project Traffic Management Plan ensured that no incidents with non-site interfacing traffic occurred during the project. To help alleviate the inevitable additional strain on the local road network from the site traffic Keltbray utilised our river based facility at Thames Wharf in Silvertown to service the site with barges along the River Thames for waste removal and delivery of new materials for Balfour Beatty. Sensitive 3rd Parties and Neighbouring Properties - Outside the site boundary numerous shops , offices and a major hotel were in close proximity to the site and through close liaison with the project team and the EHO’s from both Southwark and the City of London minimal disruption to these premises was achieved throughout the duration of the works due to Keltbray ensuring that the works were planned and executed within the set parameters which were set out in a Section 61 agreement. NWR & LUL assets along with adjacent structures were monitored for movement and vibration 24/7 to ensure that the demolition and excavation works did not adversely affect any of the surrounding buildings or assets. On the back of Keltbray’s performance at Blackfriars North and the additional project for Works on Blackfriars Station South was successfully negotiated and undertaken: - (Contract Profile C926)
- Client : Balfour Beatty / Network Rail
- Location : London
- Value : £11m