This £5m contract is the latest stage in the complete renovation of the Bridge, which began in 2003 as part of Transport for London's £10bn Investment Programme.

Interserve Project Services Ltd. (previously known as Tilbury Douglas Construction) has worked closely with TfL, the client's representative and designers to develop the tender designs, gain the necessary approvals/consents from numerous stakeholders, third parties and statutory authorities as well as carrying out consultations with English Heritage.

The permanent works are being completed entirely from the river utilising Interserve's marine based construction plant. This includes the recently refurbished 'Tilman' pontoon with 110t capacity crawler crane and other construction barges. General Marine’s tugs ‘Revenge’ and ‘Sir Aubery’ have been used to position these barges and for general towage duties.

The site office complex is constructed on temporary piled foundations in the River, directly opposite the Houses of Parliament and upriver from the 'London Eye' (a previous marine based contract where Interserve undertook the temporary and permanent structures works to facilitate wheel erection). This is close to Number 7 Arch, which will be closed throughout the work. The other arches are/have been closed in turn as the work progresses.

The fascia replacement works consist of the removal and replacement of 14 cast iron self supporting fascia arches (originally erected in 1862) which have been weakened over the years by thermal movements and ship/barge impacts. The works are being undertaken over several river span possessions, whilst maintaining the structure open to both pedestrians and vehicular traffic at all times. This is being achieved by innovative temporary works solutions, fabricated and assembled at a separate location and transported to site by river for installation.

Interserve has previously worked on other London river projects including Greenwich Pier Refurbishment, River Wall Repairs at Blackwall and Convoys Jetty.

The full Bridge project is expected to be completed in 2009 and will include completely replacing the lighting and resurfacing the road. Minimising disruption on this key location has been essential to the project's success.

'By working from floating work platforms and scaffolding in the river, taking deliveries from the river, even positioning the site offices in the river, TfL has caused minimal disruption to pedestrians and road users,' said project manager, Phiroz Dalal. 'Footpath and carriageway capacities have been maintained and we have also worked closely with the Port of London Authority, London River Services and the Environment Agency to ensure safe and minimal disruption to river traffic.'

The project has involved scour protection works by Mowlem, completed in 2005; fascia replacement, due for completion at the end of 2007; refurbishment of lighting, due for completion in 2008; resurfacing, due for completion in 2008; corrosion protection, due for completion in 2009.

By Graeme Ewens