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Exclusive: Dragados' travelators stole a march on Bank Tube rivals

Airport-style travelators were the key innovation that won Spanish contractor Dragados London Underground’s (LU) complex £625M Bank Station upgrade contract, NCE can exclusively reveal.

Two 94m long travelling walkways will significantly speed the journey of passengers travelling to and from Central Line platforms.

Dragados’ unique travelator solution was a major factor in it receiving the top score in London Underground’s evaluation system which was deliberately weighted to reward schemes that cut passenger journey time and congestion in the station.

Dragados scored 72.5, way ahead of the second placed bidder on 56.3 points. The effective value of a quality point in the evaluation was worth about £10M.

“We measure value in terms of many more things apart from cost,” said LU capital programmes director David Waboso. “The key value thing about Bank is: how can we get more people through the station? How will we keep the place open when we build [the station] and then provide additional capacity in the future? Capacity is the very big prize.”

The Spanish contractor was revealed as preferred bidder last month, beating off competition from three other UK-led teams in the first bid competition to use LU’s Innovative Contractor Engagement (ICE) procurement method.

ICE was devised by LU as a means to encourage innovation at tender stage. Bid teams were set the task of improving on LU’s base case design, with the intention that LU would buy good ideas off losing bidders.

But LU has said that so complete is Dragados’ solution that it has no need of the other bidders’ solutions.

The base case design sought to relieve congestion at the hugely busy interchange station by creating a new ticket office and entrance at ground level and building a new running tunnel and platform for the southbound Northern Line with the existing tunnel converted into additional circulation space. Extra tunnels would create a new pedestrian link to the Central Line platforms.

But Dragados’ innovative solution significantly improved the base case by simplifying the pedestrian tunnel layout and making room for the travelators.

It also significantly improves on the base design by replacing lifts with triple-escalators throughout.

Taken together, modelling shows that Dragados’ solution will cut an average 11 minute-plus journey through the station by more than 90 seconds. “It’s the simplicity of the layout that won it for us. But the travelator was the real winning idea,” Dragados project director Danny Duggan told NCE.

“Modelling shows we have made a vast improvement in journey time with every single journey one and half minutes faster. Rather than focusing on cost we were driven by adding value, and that changed our behaviours,” he said.

Dragados also found ways to speed construction and reduce the planned closure of the Northern Line by five weeks, chiefly by finding a new site for the access shaft for tunnelling operations. This allows work on the ground level station to be carried out concurrently with the tunnelling.

Taken together, Dragados’ solution boosts the scheme benefit to cost ratio from 2.4:1 to 3.5:1.
In addition to adding significantly to the benefits it also cut the estimated final cost by almost 10% to £564M.

“The ICE process LU has bought to the market has allowed Dragados to show the innovation and capability we can bring to solving client problems and delivering value driven solutions,” said Dragados managing director for England & Ireland Javier Teulón.

Supply chain’s crucial role

Dragados rail director and Bank project director Danny Duggan told NCE that tier two suppliers, bought in to exclusive agreements were key to the contract win.

Duggan said the four, tier two contractors played a particularly key role, providing their services during the lengthy tender process for free with the knowledge that they would get to carry out the work should the bid succeed.

These four are Geocisa as settlement mitigation specialists; Cleshar as track and possession management specialists; Keltbray as demolition experts; and T Clarke as mechanical, electrical and station power suppliers.

As revealed in NCE last week, the Dragados design and build supply chain also includes URS as lead designer, Dr Sauer & Partners as sprayed concrete tunnel designers and Wilkinson Eyre Architects.

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