HS2 'green tunnel’ takes major step forward

In a HS2 video update, HS2 and EKFB project managers discuss the progress being made on the Chipping Warden ‘green tunnel’.

Transcript

00:00Our trains will pass through the second green tunnel on this section, the 1.5 mile or 2.5

00:05kilometre long Chipping Warden Green Tunnel. Like Great Worth, we are constructing this tunnel in

00:10two sections, each separated by a road. Construction started in 2022 and whilst our team have faced

00:16many challenges, this is now the most advanced green tunnel on this section and lessons learned

00:20during its delivery are helping to accelerate productivity on our green tunnels at Great Worth

00:24and Wendover in Buckinghamshire. Construction of the northern section is now largely complete

00:29with over one mile of concrete, foundations and blinding in place, over 1500 metres of

00:35precast concrete arches installed and over 1100 metres of the site has been handed to

00:40our Earthworks team for backfill. Our team is building the northern porous portal which

00:44will reduce the noise of the trains entering and exiting the tunnel along with the small

00:48portal buildings to house safety and electrical equipment. At the southern end the concrete

00:53foundations are almost complete and more than half of the precast concrete arches are installed.

00:59We are here at Chipping Warden North at the north porous portal where we are carrying

01:05on with the install of the porous portal itself which started just about a month ago and it

01:09is progressing nice and steady at the moment. The weather has been fantastic so far this

01:13year and we have really made the most of it, in particular Earthworks and the tunnel team.

01:17We have handed over 1000 metres, we have handed over section 6 which is where the A361

01:21is being diverted. Earthworks have been really really hard to actually get it to a phase where

01:25they can now hand it over to the highways team and they're starting to work on it. So the key for us

01:30is getting the road diverted, creating that connectivity back to the local neighbourhoods and

01:36also gives us the opportunity then to take up the plug and finally join up this piece of tunnel behind

01:41us which will be a massive milestone for us. We've got the porous portal as you said there we started that,

01:47we'll finish that off this year. We then have the porous portal coming up in about two months over at Chipping South.

01:51So I took a lot of lessons learned from this one and take it over to Chipping South because that's a

01:56big piece over there to complete. In terms of other works coming up at the moment, a lot of handover,

02:02handed over to Earthworks and like I said the key at the moment is making sure we're ready for the

02:07future works that aren't directly coming now but next year time Robust Curves needs to be as efficient as possible.

02:12So