Modern Railways – April 2019

64 Modern Railways April 2019 http://www.modern-railways.com

BALCOMBE TUNNEL JUNCTION

Unlike some of the major blockades of the recent

past at places like Waterloo and London Bridge,

the blockade of the southern stretch of the

Brighton main line did not have a grand aim such

as platform lengthening or major layout changes.

Rather, it gave a chance to get on with some of the

‘uncomplicated stuff ’ identified by Chris Gibb.

The most critical site was Balcombe Tunnel

Junction, as the S&C replacement work here

was of the ‘once you’ve started, you’ve got to

finish it completely’ nature, giving the risk of

over-running. In the nine-day blockade, seven

days were allocated to 24-hour construction

working at this site, a day to commissioning

and half a day to resilience testing. Most work

elsewhere on the blockade, such as the extensive

tunnel drainage works, were of the type that

could be paused mid-job in the event that not

everything planned got done in the blockade.

The S&C at Balcombe Tunnel Junction was

life-expired and eight point ends and 600 yards of

plain line track were renewed during the blockade.

Also a diamond crossing, a maintenance-heavy

and vulnerable element in the track design, was

removed and replaced by two separate crossovers.

Linespeed for trains crossing over was raised from

20mph to 40mph in the process. Two signals

were moved as part of the job, points heating

upgraded and new track isolation switches –

improving the process for switching off the current

supply to take a possession – were installed.

‘The purpose of the work was to make this

junction more resilient’ explains Adam Kotulecki,

Project Manager on the job working for the

S&C Alliance of Network Rail, Aecom and Colas

that was responsible for this section of work.

Eighty track panels were delivered by road

for the job, with redundant track being taken

Tampers in possession: looking north at Balcombe Tunnel Junction on 22 February 2019.

The diamond that has been replaced was in the far distance. Jamie Squibbs

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