14 June 2011

Perfect planning is a key ingredient for the Costain-Laing O’Rourke joint venture (jv) remodelling project at London’s Farringdon rail station.

The project is preparing the 19th century station to handle a revamped Thameslink service running north-south through the capital. This includes lengthening the platforms, building a new trainshed roof and creating an integrated ticket hall that will serve both the overground and underground lines passing through the station as well as the future east-west Crossrail link.

To do this means taking frequent possessions of the tracks at Farringdon.  A possession is railway terminology to describe a section of track that a contractor literally takes possession of in order to carry out maintenance or construction works.  The typical duration of a possession at Farringdon is 52 hours over a weekend. During this period all passenger services are suspended along that section of track.

Responsibility for ensuring everything goes smoothly lies with Possession Planners Amer Inayat and Atif Tufail. “We have two different organisations to deal with at Farringdon – Network Rail [for the overground works] (NR) and London Underground (LUL). The job we’re building is for Network Rail but because it runs through an LUL station there’s obviously an interface,” explained Atif.

LUL is using the opportunity to undertake work on its station at the same time as the NR possessions.

Generally, NR possessions last from close of services on Friday night to Sunday morning, or early on Mondays. LUL possessions usually start at 1.45am on Saturdays and run until Mondays.

However, separate applications have also to be made to close the actual station, which sometimes remains open at weekends allowing the public access to use ticket machines or charge their Oyster electronic rail passes.

As well as these weekend closures (and occasional longer spells over public holidays), the team frequently work during what LUL refers to as Engineering Hours and Network Rail calls White Periods during mid-week nights.

However, in the case of LUL the last Tube train departs around 1am and the track has to be handed back at 4am in preparation for services starting around an hour later.

With NR the last passenger trains are at 22:30 with start of traffic again at 04:30. However, once the isolations have taken place this period reduces from 23:30 to 03:30: “We have a maximum of three hours on LUL and four hours on NR, however some works require isolation of both the LUL and NR tracks which leaves us with only two hours,” says Atif. “We do what we can. Usually we prepare for the weekend possessions so we can have a proper go at the work over the longer period.”

A hawk-like watch has to be kept on the progress of overnight or weekend work, as handing track back late incurs major financial penalties. "Since the job started three years ago, we’ve never overrun on one of our possessions,” he says.

Both NR and LUL need precise information on what work is being done, and how – down to details of what plant is required and how it will access and exit the site.

Before any works are carried out on or near the line on NR, a Safe System of Work (SSOW) plan needs to be produced.  This is a document to inform the Controller of Site Safety the location of the works, access/egress points, isolation details, whether there are trains running, line speed and direction and any other hazards associated with the site of work. 

One plan is required for each work group. To give an idea of the number of documents that are produced, over the Easter Possession Amer Inayat, Costain’s only SSOW Planner, produced over 100 of them.

To ensure possessions run smoothly, Atif attends two ‘red, amber, green’ (RAG) meetings each week where clients and contractors go through possessions planned for the following 14 weeks.

This information is updated regularly on the ‘RAG sheet’ that is distributed through the project team and Atif talks to team members daily. They are also circulated with details of which possessions have been approved…or declined.

“We’ve never been turned down by LUL as such,” says Atif, “but possessions have been refused for external reasons. For example, LUL wanted to keep services running for the royal wedding during the holiday Friday and NR shortened their possession to cope with the London Marathon.”

 

Ends