Unique HS2 tunnel portal completed
25 Apr 2025Our Align JV builds tunnel extensions for HS2 to stop sonic booms from 200mph trains entering the 10-mile Chiltern Tunnel.
So we're in precast factory for the viaduct segments
for the Colne Valley Viaduct.
It's a purpose built factory for the 1,000 segments
that we have to prefabricate for the viaduct.
This is a 3.4 kilometre long viaduct,
which we are building as a segmental bridge.
So meaning it's sliced into 1,000 segments,
and that's the first one of these 1,000 segments
that will effectively make up the deck.
So we're using the matchcast principle.
So basically, we are pouring each segment against the previous one.
So we have to pour them in the correct sequence in the same sequence
that we'll be erecting them.
That ensures that we have a perfect matching
between the two faces of the segments.
Behind me, you have the first segment that we poured.
We've now moved it into what we call the matchcast position
so that we can ready the rebar cage for the second pouring,
which will be done in a, in a few days.
Once the second segment will be
poured, we'll move the first segment out of the factory
through the big doors that are on the on this side,
and then it will go into a finishing area, if there's any finishing to be done,
and it will then go on to storage
where it will wait for the start of the erection of the viaduct.
When the factory will be running at full speed, basically,
the aim is to pour 12 segments a week. Each segment is unique.
They vary in size. They vary in the complexity of the reinforcement.
The only size that is always constant is the width,
which never changes throughout the viaduct. This is the first segment.
There's still 999 to go, so there's still a lot of hard work
ahead of us and a lot of challenges.
But we're really proud to show this first one
and hopefully it will be a proud moment
in a, in a few years to show the 1,000th.
