Bermondsey dive under open

[IanKR]

Assuming the part-demolished viaduct is for the CHX tracks (southern viaduct), it looks like there is also a fly-under down on the south side of the CST tracks (northern viaduct)?
http://cdn.londonreconnections.com/2013/Bermondsey-DiveUnder.png

 

[Barn]

Assuming the part-demolished viaduct is for the CHX tracks (southern viaduct), it looks like there is also a fly-under down on the south side of the CST tracks (northern viaduct)?
http://cdn.londonreconnections.com/2013/Bermondsey-DiveUnder.png

I *think* that line was designed for the proposal to run Thameslink services to Dartford via Bexleyheath / Sidcup. I'm not sure what use it'll see now that those services are no longer anticipated - others will know.

 

[hwl]

I *think* that line was designed for the proposal to run Thameslink services to Dartford via Bexleyheath / Sidcup. I'm not sure what use it'll see now that those services are no longer anticipated - others will know.

Indeed that was the original purpose linking Up kent slow to Up Thameslink, it now provides a link between the CHX platforms at London Bridge and the Slow /CST lines through New Cross (or Greenwich). Using will off course create lots of potentially conflicting moves so it is probably for engineering works on Sundays only type use (though possibly a few down CHX - Lewisham stoppers the rest of the week as it avoids using Tanners Hill)

 

[swt_passenger]

I think this updated picture, posted by Unravelled (David Harvey) on flickr yesterday, shows the same reinforced brick pier I mentioned in post #13, back on page 1.


Bermondsey diveunder works by David Harvey, on Flickr

Is it likely therefore that the presence of the reinforcement around the base means that this will be the 'join' between the old (level) and new (descending) viaduct sections?

Edited to add:

Here's another odd detail, seen on another picture taken yesterday:


Bermondsey diveunder works by David Harvey, on Flickr

If you magnify the photo and look at the south end faces of the brick piers, there's a set of red/blue painted marks that suggest a gradual slope down towards the west (London Bridge direction). Are they possibly recycling the piers as part of the new viaduct for Southeastern services towards the underpass?

 

[hwl]

I think this updated picture, posted by Unravelled (David Harvey) on flickr yesterday, shows the same reinforced brick pier I mentioned in post #13, back on page 1.


Bermondsey diveunder works by David Harvey, on Flickr

Is it likely therefore that the presence of the reinforcement around the base means that this will be the 'join' between the old (level) and new (descending) viaduct sections?

Edited to add:

Here's another odd detail, seen on another picture taken yesterday:


Bermondsey diveunder works by David Harvey, on Flickr

If you magnify the photo and look at the south end faces of the brick piers, there's a set of red/blue painted marks that suggest a gradual slope down towards the west (London Bridge direction). Are they possibly recycling the piers as part of the new viaduct for Southeastern services towards the underpass?

The point demolition has stopped aligns with the point where the new virtually complete viaduct starts to descend towards the dive under structure.

If you look at some of David's other recent photos (Saturday 27th June) you can see they are neatening up the brickwork on the pier that has the been protected for example:
https://www.flickr.com/photos/unravelled/18592643724/in/photostream/
https://www.flickr.com/photos/unravelled/19209242982/in/photostream/


I was looking through David's photos before I came here and I also had the idea that they might also reuse the piers, the demolition has stopped just the right amount above the red/blue lines to allow the brick work to be neatened up and reused. Assuming a similar construction method to the new viaduct you could add concrete structure to act as a base for arches on to the existing piers. The piers spacing on the new viaduct appears to be exactly half the spacing on the part demolished CHX line viaduct so if new intermediate piers were added the top half of the new structure could be identical to new viaduct...

Previous survey marks in white that match the red /blue marks can also be seen on some on the piers in this photo:
https://www.flickr.com/photos/unravelled/17596109261/in/album-72157633053354298/

(May 2015)

 

[Chrisgr31]

I have read somewhere, maybe in a Skanksa (think they are the contractors) article that they are reusing some of the piers, and that they have recreated arches in order to do so, which is very unusual in todays railway construction. However it will make the construction process quicker.

 

[IanKR]

[...] If you look at some of David's other recent photos (Saturday 27th June) you can see they are neatening up the brickwork on the pier that has the been protected for example:
https://www.flickr.com/photos/unravelled/18592643724/in/photostream/
https://www.flickr.com/photos/unravelled/19209242982/in/photostream/ [...]

Great pictures. Thanks for the link.

 

[swt_passenger]

Some new photos on David Harvey's flickr, including the remnants of the reinforced bridge over Bolina Rd:



Bermondsey diveunder works by David Harvey, on Flickr

 

[thebigcheese]

It's been quite interesting seeing how work is progressing on my occasional commute to Waterloo East although a bit disappointing at the boards that have gone up at London Bridge so you can't the station being rebuilt from the train

 

[Bald Rick]

Some new photos on David Harvey's flickr, including the remnants of the reinforced bridge over Bolina Rd:



Bermondsey diveunder works by David Harvey, on Flickr

That's a few days old, that pier went on Wednesday

 

[Bald Rick]

London Reconnections have just published an article on the subject...

http://www.londonreconnections.com/2015/bermondsey-diveunder/

 

[FOH]

I see the brand new sections have had their tagging christening today. Maybe graffito's read London Reconnections

 

[Skimpot flyer]

I thought people might like to see the scale of the demolition and reconstruction work on the approaches to London Bridge, as viewed from a train I was on yesterday.

I hadn't been to London Bridge since diversion of all Thameslink services to the Elephant And Castle route, and I was surprised at the extent of the works !

 

[swt_passenger]

David Harvey has recently uploaded a number of new photos and a video of the Bermondsey site progress to his flickr account.

As an example, the photo below shows the current state of the new arches that will take the Thameslink lines towards their new flyover, note the slight upward slope compared to the eventual Cannon St lines behind.

Much more to see once in his photo stream:



Bermondsey diveunder works by David Harvey, on Flickr

 

[ComUtoR]

I had a thought last night about the concrete construction. Why isn't it being done in steel ? Surely steel construction would mean a much faster and longer lasting structure ?

The concrete must take a huge amount of time to build the forms, pour and then set.


Thanks in advance.

 

[Deepgreen]

I had a thought last night about the concrete construction. Why isn't it being done in steel ? Surely steel construction would mean a much faster and longer lasting structure ?

The concrete must take a huge amount of time to build the forms, pour and then set.


Thanks in advance.

Is it possibly that the arches may be used as tenancies after completion, and concrete allows easier internal (ceiling) fitment fixing by the occupiers? Or an electrical earthing issue?

 

[ComUtoR]

Is it possibly that the arches may be used as tenancies after completion, and concrete allows easier internal (ceiling) fitment fixing by the occupiers? Or an electrical earthing issue?

Steel can do the same thing.

I must admit that my curiosity has come from both watching programs like grand designs where steel frame construction goes up super fast and is extremely durable. FYI it usually has those concrete block fillers that slide into the I beams. Other construction programs show wide use of steel constructions.

I've also watched a few rail bridges go up in recent years and its typically got a steal based construction too. Most of the bridges have been updated with steel due to the age of the concrete and brick works.

I'm not an engineer or have any engineering knowledge, just really interested

 

[Bald Rick]

I had a thought last night about the concrete construction. Why isn't it being done in steel ? Surely steel construction would mean a much faster and longer lasting structure ?

The concrete must take a huge amount of time to build the forms, pour and then set.


Thanks in advance.

The arches are precast off site, and go up very quickly. AIUI it was part of the planning conditions to replicate the old arches as far as possible.

 

[ComUtoR]

I appreciate that and thanks for the response.

I watch the construction progress regularly and generally from a good viewpoint. The flyover part could have been constructed from steel.

Could it be because of costs ?

 

[swt_passenger]

I appreciate that and thanks for the response.

I watch the construction progress regularly and generally from a good viewpoint. The flyover part could have been constructed from steel.

Could it be because of costs ?

Derailment containment requires mass concrete, IIRC.

It needs to be solid enough that under any credible scenario a train coming off the tracks in the dive under cannot affect the lines over the top.

There are similarities with the concrete walls and decks which can be seen at Reading, where the fast lines are on the viaduct and the west curve box, the Festival line box and the feeder lines box intersect at various angles underneath.

 

[hwl]

Derailment containment requires mass concrete, IIRC.

It needs to be solid enough that under any credible scenario a train coming off the tracks in the dive under cannot affect the lines over the top.

Indeed it effectively does - Notice the steel work on the recently modified bridge at St John is encased in concrete for this reason.

A lesson learned from the 1957 Crash at "Lewisham" that brought the Lewisham - Nunhead bridge down on top of the 4 tracks just south of St Johns.

https://www.youtube.com/watch?v=k2zZIFtg9KE&feature=related

 

[kdoganorak]

I travel via South Bermondsey frequently and have recently noticed you can see concrete pillars/piers in the distance - probably for one of the ramps on the London Bridge side.

The first, single track bit on the other side comleted last year is too far away to see from here as you pass on the train but this new bit sticks out, particularly as it seems to be mostly white concrete with no brickwork (yet).

I might try and take a few picies from here or from a train via new cross gate next week.

Don't suppose anyone has any other progress updates?

 

[Bald Rick]

Read the latest comments on the London Reconnections article on the subject.

http://www.londonreconnections.com/2015/bermondsey-diveunder/#comment-267393

 

[kdoganorak]

Read the latest comments on the London Reconnections article on the subject.

http://www.londonreconnections.com/2015/bermondsey-diveunder/#comment-267393

Thanks! Quite a lot of progress then. I was on that guy's flickr yesterday and somehow missed that. It might be the Western end of the box I can see.

 

[Chrisgr31]

Not sure this question should be in this thread or the London Bridge one, but they have taken away a lot of trackbed stone from the section of track between the diveunder and London Bridge, and then brought a whole load of stone back.

Is it in fact the same stone and taken away to wash all the years of accumulated rubbish from it or is it new stone? If they dont use the old stone here what happens to it?

 

[swt_passenger]

Not sure this question should be in this thread or the London Bridge one, but they have taken away a lot of trackbed stone from the section of track between the diveunder and London Bridge, and then brought a whole load of stone back.

Is it in fact the same stone and taken away to wash all the years of accumulated rubbish from it or is it new stone? If they dont use the old stone here what happens to it?

Old ballast gets worn too smooth, and too small, so eventually it doesn't provide the necessary interlocking for track restraint no matter how clean you can get it. I would expect they would take the opportunity of such an accessible worksite to do a 100% removal and replace - if only to get a head start on future maintenance requirements.

But on the operational railway the High Output Ballast Cleaning train basically runs along and treats the ballast by cutting it all out, then sorting it for size, cleaning most stone and replacement with some new stone added.

Ballast that is beyond further use on the railway is washed and recycled into the construction industry, it is done at places like Whitemoor, Westbury and Eastleigh to name but a few.

 

[HarleyDavidson]

I've been told that somewhat ironically that a fair amount actually ends up in the construction of new road projects.

 

[SpacePhoenix]

When this or any other dive-under/fly-under or flyover is completed do drivers have to learn and then sign it or does it get classed as the existing route that they already sign?

 

[swt_passenger]

When this or any other dive-under/fly-under or flyover is completed do drivers have to learn and then sign it or does it get classed as the existing route that they already sign?

On the day it opens they'll use the new route, (probably extremely cautiously), based on prior training using video simulation. The fact that a particular route will now be running through or over a concrete box doesn't add a lot to the basic problem that they also had to overcome back in January when the new platforms 7, 8 and 9 at London Bridge, and the new Borough Market flyover opened. The drivers still had to take a new route that they had not all driven over before.

This is also what happened at Reading when that major flyover opened, and presumably what has recently been done for Norton Bridge.

 

[najaB]

When this or any other dive-under/fly-under or flyover is completed do drivers have to learn and then sign it...

Not a driver but I'd expect that it would classed as new, since your approach speed to a flat junction will be completely different as compared to a grade-separated junction. Which will have affects on braking points, etc.

I seem to remember that there was route learning required before the Hitchin flyover was brought into use.