Every now and then you get a project come along which really captures the imagination – Tennison Road Bridge in Croydon was just one of those projects.
Our first contact with came via our website. Normally we get involved in remedial issues regarding a problem that has built up over years so the scope is to rectify the issues, clean up the site and prevent problems, but this one was different.
Firstly, the bridge had not even been built when we first got involved. We worked off engineering drawings and priced to provide a solution in a tender type format (we are very used to doing this type of pricing) but somehow this all seemed more exciting – the guys we were dealing with had a passion and energy to get the right solution in place.
Network Rail were very forward thinking in getting the bird protection sorted out to prevent a problem ever happening – they also specified our favorite bird proofing material, weld mesh, to provide a long lasting and permanent solution, which will last without maintenance for at least 20 years.
After the normal preamble, I was called up to the site to see the extent of the project and talk through our proposed solution with the Site Manger and the End Client.
This was my first view of the monolith of a bridge. It was huge. Basically the bridge had been built on the road in front of where the old bridge once stood – this had been demolished a while before to make way for the new bridge. The plan was to build everything, install all services in the bridge (including the bird protection) and then at a pre-determined time, launch the bridge over the railway tracks and position the bridge.
All sounds so simple, but it has only been done a few times before in the world, and on a much smaller scale. A huge crane would be used to lift a nosepiece in place that would counter balance the bridge and be used to guide it over the railway tracks. Hydraulic rams would then literally push the bridge over the gap and into place.
Anyway, design approved, negotiation completed and paperwork signed – the job was ours!
Installation dates were confirmed and we had just a few days in which to complete the challenge before the big crane arrived – we were the last trade on site to do any installation work, so the pressure was on.
As usual, our fantastic supplier partners rallied round to get materials on site ready for us. Access to the underside structure was via tower platforms as the headroom was only 2.5 meters or so – again a unique experience for us as we normally are working in cherry pickers etc.
So the day arrived for us to start – as normal a site induction and safety briefing was undertaken – all our staff carry CSCS cards anyway, but each site is slightly different and policies change from site to site – the funny thing was the guy who took our induction had such a broad Irish accent he was almost impossible to understand!
After the safety induction was completed, we measured up and got most of the sheets cut to size and T bars in place ready to finally position and clamp on the following day – being a new bridge all the dimensions were as per drawing so it allowed us to proceed quickly. We made astonishing progress before leaving site for the night.
Next morning, after the daily safety briefing, we moved off to get going again with one team positioning and clamping the weld mesh sheeting in place whilst another team attended to a particularly difficult section with complex cuts and fixings. All was going so well until the Network Rail project manager arrived.
He wanted us to place more vibration and insulation proofing in the bridge – something we always do – but not to this extent. The implications were to basically undo everything we had done and fit more rubber everywhere. The other problem was our normal supplier had exhausted stocks so it meant finding new sources locally in London – for a collection that day.
After a few hours, we had found a source, collected materials, dismantled the proofing already installed and were back to starting point but with much more rubber!
In most projects, this type of things happens so we record the events using Change Control Notices extensively to capture changes and specification amendments ensuring the quality standards are maintained and time lines changes are agreed.
Despite all the extra work and time we needed, the final sheet was fixed in place with a few hours to spare before the crane was due to arrive. The teams were exhausted but happy to have completed this epic job on time.
Some of the feedback from other workers on site was amazing – we also had a delegation of VIPs visit the site just as we were finishing and they were full of praise for us as a team and the whole construction site teams as well – always nice to get a pat on the back.
On Saturday 6th December, history was made in Croydon. The bridge was successfully moved into place without any disruption to the rail network. The event was filmed using time-lapse photography so we could all see this amazing event. We are extremely proud to be part of this whole chapter in history – please watch the video and be amazed at this engineering feat.
Watch the Time Lapse Footage of The Bridge Being Inched Into Place – Tennison Road Bridge Replacement Live Launch December 2014