Sandwiched between the Westway and the Hammersmith & City Line is Crossrail’s Royal Oak Portal – the point from which central section tunnelling will start in the west and the point at which trains will enter or leave the tunnelled section.
Construction of the Portal has now largely been completed, with tunnelling due to commence next year. At only 21m wide, its an incredibly narrow worksite and, as the photo below demonstrates, one that borders pretty much directly onto the live railway at various points.
A Circle service thunders past
For those familiar with this particular stretch of the Hammersmith & City, the site took over (amongst other things) the site formerly occupied by the old black cab park (complete with café and petrol pumps). All of that, and more, has long since disappeared beneath the site approach.
Looking towards Royal Oak Station
The Remains of the Arches
Spoil work continues as an FGW service approaches Paddington
Beneath the Westway
Advancing towards the Portal itself presents a rare opportunity to see Royal Oak from its northern side.
Royal Oak from the north
Royal Oak close up
Hampden Street footbridge sits at the start of the 285m long ramp down to the Tunnel Eyes. This was raised during an Easter blockage to facilitate the works beneath it, and the evidence of that can be seen on the second photo below. It will, however, still need to be lifted twice once the TBMs are assembled, in order to allow them to pass beneath.
The Hampden Street footbridge
The additional height added to the Hampden Street footbridge
The area cleared for TBM assembly is also where the new turnback sidings will ultimately be located. This can be seen in the photo below. First Group’s buses will need to be moved off the rear of the site to Atlas Road until after construction is complete. These will ultimately return to new facilities on top of the sidings at the end of the project.
Interestingly – especially in the context of Kensington & Chelsea’s push for a Crossrail station at Royal Oak – talking to the contractors on site revealed that the siding platforms that featured on the original plans will now not be built. Unfortunately they were unable to confirm when this decision was made.
The siding site
The Portal itself has elements of the Death Star trench about it when viewed from the surface. Approximately 100m of Sheet Pile Wall gives way to another 190m of D-Wall as the retained cutting gets deeper. Temporary props are still in place at the Tunnel Eye end, marking the point at which the evacuation stairway will eventually be sited.
The view from the side of the Portal
Temporary Props over the Tunnel Eyes
Heading into the Portal itself, a base slab on which the trackbed will eventually be placed gently slopes down to the Tunnel Eyes. A number of Permanent Props are in place towards the end, strangely reminiscient of the Connaught Tunnel (although more utilitarian in design).
Looking back up as the ramp begins its descent
The cutting deepens
Looking towards the Tunnel Eyes
The Permanent Props cast shadows over the proceedings
The cutting (with help from Matt from Sian Formwork in the Cherry)
The Tunnel Eyes from above (again, with thanks to Matt)
The Tunnel Eyes themselves have a diameter of 7.24m and sit in front of the tunnel head. It’s these the TBMs will use to drive off from when they begin tunnelling. Looking inside, they actually gently angle outwards, reflecting the fact that the twin tunnels will bow out slightly beneath Paddington.
Work continues at the Tunnel Eyes
The Tunnel Eyes up close
Looking back from the Eyes gives an idea of the track level
Overall, its an interesting and compact site, but one that will shortly be a hive of activity. Once the TBMs arrive and tunnelling begins, we will endeavour to engineer a return – something that would likely produce a very different set of photos.
Excellent pics John. It’s strange to see a finished component of Crossrail when you consider that it’s at least 6 years away yet! Still, gives us plenty to talk about and look at until then.
“Tunnel Eyes”? That’s a term I haven’t heard before… I’m used to them being called tunnel “mouths”!
Think of them as being like the eye of the needle – it’s through them that the TBMs will start carving into the tunnel head behind.
Nice photos JB.
Interesting that the ‘eyes’ need to be recessed, not just be circles drawn on a flat wall.
It has been obvious when travelling into Paddington that significant progress was being made with the Royal Oak Portal. Thanks JB for giving us a closer look. Perhaps you should explain that D-wall means Diaphragm Wall (& then have to explain what that is too!). Tunnel eyes is a construction term, meaning the starting or finishing points for a tunnel drive. They are almost certainly recessed because the wall within the circles is only temporary (so needs to be fairly easily removed), while the part outside the circles will be permanent. It would be great to see preview pics of the TBMs, but I guess they are too far away to be easily visited (in Germany?). These beasts are awesome when fully assembled with all the ‘train’ that follows behind the cutting shield.
Another excellent article from a great website. Keep it up.
Think of them as being like the eye of the needle – it’s through them that the TBMs will start carving into the tunnel head behind.
Don’t use analogies like that – otherwise we’ll end up with a load of camels driving the TBMs
For the “Remains Of The Arches” picture, does that imply arches have been demolished as part of this work? Great pics – looking forward to more. Also, is there that third and final part to the Euston Arch piece run a year or two ago?
First tunnel mouths, then tunnel eyes, and now an entire tunnel head…
@Ratty
It appears that if you are starting tunnelling from a location you need eyes to position it precisely. If you are tunnelling to a location you merely need to mark out where the TBM will emerge.
As I understand, it the live railway won’t be called Crossrail, anyone know of any names floating around?
What were the arches that were demolished originally for?
Hope the TBM drivers are better than me when I try and drill holes on a tiled surface. Always endup skidding across the wall and landing in the bath. What they need is a couple of enormous strips of insulating tape stuck over where the drill bit will start.
They can have that tip for free, next time I charge £500 a day.
Now is probably a good time for the Curator of the London Transport Museum to worry about how they will get a TBM through the doors and what exhibits will need to be moved to one or even two sides.
Fantastics pics. That looks like quite a gradient there, do you know how steep?
Now is probably a good time for the Curator of the London Transport Museum to worry about how they will get a TBM through the doors and what exhibits will need to be moved to one or even two sides.
The cutting head for the DLR extension to Lewisham is displayed in the ticket hall area of the Greenwich Cutty Sark station.
I think that the arches were part of the original ramp that led up to the former goods yard. I hope that answers your question anonymous
Some pedantry for Pedantic of Purley to enjoy:
If you are tunnelling to a location you merely need to mark out where the TBM will emerge.
Why? Can the TBM see through the rock to the exposed side?
Fantastic pictures! It certainly will be very exciting to see what it will look like when it has been completed.
Sophie Hobson, deputy editor London Loves Business
http://www.londonlovesbusiness.com/
Thank you for giving us a view from inside the trench, it’s been difficult to appreciate the extent of the work from passing trains. Building Crossrail should have happened twenty years ago, but at least now it has finally started in earnest.
When does tunnel boring works commence?
Construction of Crossrail’s tunnels will begin in spring 2012 when the first tunnel boring machine is launched from Royal Oak. This will be followed by the launch of further TBMs to construct the remaining tunnels for the new Crossrail service.