c a s e s t u d y : n u m b e r  three

Second Severn Crossing

Invited by the client to take control of this section of a project with only 6 weeks to completion was possibly our greatest challenge in a network build that had seen us traverse the UK in a double figure of eight from Lands End to Edinburgh and back taking in London, Leicester, Leeds, Glasgow, Belfast, Dublin, Manchester, Birmingham, Bristol and now a final link to Cardiff.

The structure itself is quite amazing being 5km long and consisting of 2 x 2km viaduct sections joined together by a 1 km suspended central section. Each viaduct section comprising 2 parallel and separate tunnel like chambers supported on columns from the banks of the river. Each cross section being capable of holding possibly 5 double decker buses, 3 upright and 2 laid on top of those. Unfortunately the buses would need to be dismantled down to less than 1.5m by 0.6m to get them inside, this being the size of the only access to the viaducts, through a single door at the land end of each viaduct. Access to the central section was via the motorway hard shoulder and a lift down to the walkway landing. In addition to this, such access

required an escort and deliveries had to be made by the bridge maintenance crews.

Task

To install a 144 fibre armoured cable through the structure for the project completion date. Note;
nothing had been installed into this bridge since its construction.

In the project folder supplied by the client was a fax from the contractor that purported to be the method statement for the installation of the cable through the structure. It consisted of 12 lines. When asked where the rest of it was, I was informed by the contractor that that was it, he was duly informed that he would be going nowhere near the bridge and that that section of the project was being removed from his contract. In view of the short timescale for this project I decided to invite the bridge maintenance company to bid for the works, (who better I thought to provide a method statement that would satisfy them). The company declined for resource reasons (one of which was to impact on our operation considerably) but recommended a contractor that was familiar to them. Consequently this contractor was invited to survey the structure and put forward a bid. Whilst the method statement provided was reasonable, the number of men employed (30) and the estimated time to complete the works (9 weeks) reflected I believed a lack of true understanding of the job, in so much that this ratio calculated out at .5 metres of cable installed per hour, all at a cost of some £264,000.00. I subsequently informed our client that I was not prepared to allow this contractor on the bridge either, at which point the client requested that we undertake the work as principle contractor. Though I found this to be rather unethical the client was insistent.