by Ewan Fergus, The Herald
Early in the new year massive sections of bridge will be inched
into place to carry the M74 sweeping over the main West Coast rail
line at the Port Eglinton viaduct.
The operation, part of the massive M74 Completion Project, will
be a painstaking affair. Each of the 170-metre 4,000-tonne steel
segments has to be edged into place at a speed of just 10 metres
per hour.
The process is a delicate one, because the railway line beneath
must remain open throughout.
That means the work can only be carried out in the wee small
hours, for just two hours a night.
Despite the constraints, Transport Scotland are confident that,
like the rest of the project so far, the work will be caried out on
schedule.
The viaduct is just one of the many jobs that have to be done to
join the M74 to the M8 in Glasgow, and complete the "missing link"
in Scotland's transport network.
The scale of the project is massive and includes the
construction of 13 bridges and one underpass, but work is now
developing at speed.
At Fullarton Road, two bridges are being constructed and should
be going up in February, while the Auchen-shuggle Bridge, taking
the M74 over the Clyde, will be manoeuvred into place in June.
One of the most complex parts of the plan is being carried out
at Rutherglen Station, where both carriageways of the M74 will
cross the railway lines either side of the station itself and over
a section of the station platform.
The four-span bridge is supported at each end by re-inforced
concrete supports and at three intermediate locations by
re-inforced concrete columns. The bridge deck will be made up of
steel box girders with re-inforced concrete cast in place over
them.
The steel girders will be lifted into position over the railway
lines during the night when the rail lines are closed. Commuters
using the station will be unaffected by any of the bridge work.
Stephen McFadden, engineering representative on the M74 project,
said: "Piling work at Rutherglen Station is underway and the bridge
beams will go up in February.
"The bridge supports are concrete, and we have to pile into the
ground to build them.
"The steel beams of the four-span bridge are being fabricated in
Darlington at the moment and we should be moving them into place in
February or March.
"It's quite tricky because there is a live railway line here,
and we cannot have any impact on it, so all the work there has to
be carried out at night.
"We're piling in between the lines at the moment, and that has
to be done with care. It's complex work."
But despite the project's complexity, it is expected that the
whole M74 link will be open, on time, by August 2011 at a cost of
about £445million.
Graham Porteous, head of construction at Transport Scotland,
says it will have a massive impact on the efficiency of Glasgow's
road network, reducing congestion and making journeys easier and
faster.
Mr Porteous said: "The M74 link will remove congestion for
people who currently find themselves sitting in queues of traffic
on the M8 at rush hour in the morning.
"It will provide an alternative route to the south west and it
also opens up the development potential for the south of Glasgow,
with direct motorway access.
"Overall, it will open up a range of regeneration opportunities
for the whole of the west of Scotland."
However, the project has also been throwing up other benefits as
it progresses.
Pupils from Cairns Primary contacted Transport Scotland to say
they were interested in learning about the environmental impact of
the project.
To help pupils get a close-up view of the work without putting
themselves in danger, a viewing platform was built close to the
site where the Auchenshuggle Bridge is being built.
Mr Porteous added: "There's been a lot of engagement with
classes.
"The kids were interested in the river and from our point of
view it helps us make them aware of the project and construction
generally."
For more information log on to: www.transportscotland.gov.uk/projects
Reproduced with the permission of the Herald and Times
Group.