Stevenage platform 5

[Mcq]

Towards the end of the video (post #247) you can see what looks like the horizontal sections of gantry near the recently erected masts... Have checked open train times and unlike Kings Cross there are no freight workings shown around that section, so guessing no track is being laid just yet.

I was hoping for some 'locked off' points whilst they had possession of the ECML - ever the optimist

 

[Aictos]

Just got back from filming the work that's currently underway. Main focus is at the A602 end of the turnback where three new gantries spanning all lines have been erected.... video will be uploaded shortly - need a cuppa first as it so ruddy hot !

I look forward to it, thanks for the videos! BTW not sure how hot it was earlier up here but walking into the local Lidl was like walking into a fridge, so nice and cool!

 

[malc-c]

Here's the video of today's (as of 3pm) progress

 

[adamedwards]

Many thanks for this. Good to see heavy duty beams going in at Langley Junction which should keep the wires up. I assume the big yellow road crane had put them in?

 

[malc-c]

Many thanks for this. Good to see heavy duty beams going in at Langley Junction which should keep the wires up. I assume the big yellow road crane had put them in?

I would have thought so, and looking at the number of the portable lights around the site, it probably went in during the hours of darkness (I believe the blockade was from midnight ?). As i mentioned in the description, I've watched them build these large bases, and ramps it that area, and now we can see why.

 

[malc-c]

Work continued through the night. The crane had gone, and the guys were busy running in new cabling and checking the running of the OHL

 

[59CosG95]

Work continued through the night. The crane had gone, and the guys were busy running in new cabling and checking the running of the OHL

Looks good - seems they were re-registering the Aerial Earth wires on new SPS Stovepipes affixed to the new portal/TTC, before panning the altered catenary/contact wires to make sure it was all correctly aligned.

 

[malc-c]

I popped down this morning and the task was complete and everyone had gone home I will upload a short video of the finished work shortly.

What does surprise me was that unless there is something planned in the future which required the replacement of two headspans I can't see what the point of this weekends work at the junction was for, and it doesn't look like anything connected with the turnback was installed in readiness. Looking at the foundations for the new masts, they are all to the left of what will be the track bed (as viewed from the A602 road bridge). It's still not clear where the turn back will join the Hertford loop line as the works stop abruptly at the bridge support. If they were going to swap sides and have new hardware fitted to the existing masts ( for argument sake, say the mast with the first new head span nearest the bridge) then with this closure in place for this weekend it would have made sense to install it now. Unless that will happen at Christmas ???

 

[edwin_m]

I popped down this morning and the task was complete and everyone had gone home I will upload a short video of the finished work shortly.

What does surprise me was that unless there is something planned in the future which required the replacement of two headspans I can't see what the point of this weekends work at the junction was for, and it doesn't look like anything connected with the turnback was installed in readiness. Looking at the foundations for the new masts, they are all to the left of what will be the track bed (as viewed from the A602 road bridge). It's still not clear where the turn back will join the Hertford loop line as the works stop abruptly at the bridge support. If they were going to swap sides and have new hardware fitted to the existing masts ( for argument sake, say the mast with the first new head span nearest the bridge) then with this closure in place for this weekend it would have made sense to install it now. Unless that will happen at Christmas ???

Not sure I fully understand this, but it seems to me that the supports for the replaced headspans were in the "footprint" of the new track so had to be replaced further back from the existing track. Replacing the supports means the headspans must also be replaced, and as they don't want any new headspans they've used portals. This requires isolation and partial dismantling of the OLE on all four tracks so it makes sense to do it when the line is blocked for other reasons.

I would guess that further north the new line will be behind the existing supports which can therefore remain in place. Whether they put new cantilevers on the back of the existing masts or add extra masts for the new track remains to be seen, but either of these can be done piecemeal without a long possession/isolation of the main line so not critical to do it in the blockade. If the layout changes don't affect those headspans then they may get replaced at some point, but under someone else's programme - and budget!

Previous photos showed a single track double cantilever locating the wires above the points where the Hertford Loop joins the main line. Is this still in place and also blocking the future track? If so it suggests the point will probably be replaced by a new turnout underneath one of the new portals (after which the now-redundant support can be removed). As this possession is apparently for re-controlling the signalling they probably don't want to do anything that changes the trackside signalling equipment at the same time. The other end of what wil effectively be a crossover between the Loop track (continuing into P5) and the Down Slow will probably be underneath another of the new portals.

 

[malc-c]

I've tried to capture a few stills to try and see the point you are trying to explain. To me the new track will be to the left of the masts, more or less where the small nit of ballasted roadway is, which would line up with the rest of the foundations once they re-landscape the groundworks they had to build for the crane.

In the two images below, the one on the right was before the new beams were installed, the one on the left after. I gather you are suggesting that the new point would be installed approximately where the truck is )bottom right of the left hand image) and then run to the right of the masts once they remove the two old (now obsolete) masts, something like the third image - that would make sense and would save any alterations to the bridge.

Looking at the curvature in the alignment that would also suggest that the new track is going to follow that line.

But would it not be dangerous fitting new OHLE to the new gantries without isolating the power to at least the down slow ? - hence why I would have thought that they would have removed the old masts and fitted the hardware whilst the possession was in place this weekend.

 

[edwin_m]

I've tried to capture a few stills to try and see the point you are trying to explain. To me the new track will be to the left of the masts, more or less where the small nit of ballasted roadway is, which would line up with the rest of the foundations once they re-landscape the groundworks they had to build for the crane.

In the two images below, the one on the right was before the new beams were installed, the one on the left after. I gather you are suggesting that the new point would be installed approximately where the truck is )bottom right of the left hand image) and then run to the right of the masts once they remove the two old (now obsolete) masts, something like the third image - that would make sense and would save any alterations to the bridge.

Looking at the curvature in the alignment that would also suggest that the new track is going to follow that line.

But would it not be dangerous fitting new OHLE to the new gantries without isolating the power to at least the down slow ? - hence why I would have thought that they would have removed the old masts and fitted the hardware whilst the possession was in place this weekend.

Thanks for that, your final image captures my suggestion perfectly. It also shows better the position of the new OLE with respect to the existing turnout. You have to have a support above a set of points to correctly align the wires, and as both the existing and your suggested new turnouts are roughly below portals then I suggest you have captured the approximate layout of the new connection.

Yes some isolation may be needed to attach new equipment to the left hand side of the existing masts, but probably only of the Down Slow and Down Hertford, for which I imagine it's relatively easy to get engineering access at quieter times by diverting traffic onto the Down Fast. Even if isolation of all tracks was needed, one or more cantilevers could be installed in a routine overnight possession. If the OLE for the new track is going on new structures then these are probably far enough from the live railway that they can be done at any time with no possession at all, at least until the time comes to connect it to the existing.

What they have just done required closure of all four lines for long enough to disconnect the existing headspans, install the portals and re-connect all the wires in the correct positions. From the posts above it's clear that it took more time than would be available in a normal overnight possession. They could probably have done some OLE work further north at the same time, but the more work you plan during a blockade the more likely it is something will overrun, so you probably don't plan in something that can be done at much less risk on a separate occasion.

 

[malc-c]

I thought that the regular concrete blocks that seem to follow a curve parallel to the main lines could possibly be the foundation blocks to attach the new masts (apologies if I'm not using the correct terminology for the equipment), as can be seen in the image below - but then there are similarly placed blocks on the main line as indicated by the arrows. If the blocks are indeed foundations I'm guessing the masts and beams that would support the wires would be independent from existing equipment, and thus will / could be installed all the way from the station to the junction "off line" so to speak without any disruption to main line running, and any isolation and disruption would be when it comes to "terminating" it over the new point so that the trains can transition from the existing OHL onto the new wires, which presumably could be done overnight ?

 

[Josh_justJosh]

This morning I have noticed that Great Northern are running one train per hour from Stevenage to Morgate via Hertford North with no repacement bus service.
Obviously without a platform 5 yet.
If they can do it now without a new platform, why couldn't they have been running them last week (or for the last year)?

 

[Fred26]

This morning I have noticed that Great Northern are running one train per hour from Stevenage to Morgate via Hertford North with no repacement bus service.
Obviously without a platform 5 yet.
If they can do it now without a new platform, why couldn't they have been running them last week (or for the last year)?

They run at weekends and bank holidays as there are less train using the mainline.

 

[edwin_m]

I thought that the regular concrete blocks that seem to follow a curve parallel to the main lines could possibly be the foundation blocks to attach the new masts (apologies if I'm not using the correct terminology for the equipment), as can be seen in the image below - but then there are similarly placed blocks on the main line as indicated by the arrows. If the blocks are indeed foundations I'm guessing the masts and beams that would support the wires would be independent from existing equipment, and thus will / could be installed all the way from the station to the junction "off line" so to speak without any disruption to main line running, and any isolation and disruption would be when it comes to "terminating" it over the new point so that the trains can transition from the existing OHL onto the new wires, which presumably could be done overnight ?

These are almost certainly catchpits for the drainage. Notice how they are much closer together than the OLE masts and some are close to existing masts. If your photo is zoomable enough then you might be able to see the blue gratings that often cover the catchpits.

 

[Hadders]

This morning I have noticed that Great Northern are running one train per hour from Stevenage to Morgate via Hertford North with no repacement bus service.
Obviously without a platform 5 yet.
If they can do it now without a new platform, why couldn't they have been running them last week (or for the last year)?

@Fred26 is correct. More trains operate on weekdays and there isn’t enough time to operate the Hertford loop services to/from Stevenage as they require occupy platform 4 for too much time while they turn round.

One upside of the shambles last year was that on weekdays fewer trains were running so the bustitution was delayed for a year.

 

[hwl]

These are almost certainly catchpits for the drainage. Notice how they are much closer together than the OLE masts and some are close to existing masts. If your photo is zoomable enough then you might be able to see the blue gratings that often cover the catchpits.

Some of the pre-cast catchpit sections are clearly visible stacked up at the front centre of the photo waiting to be installed along with black plastic drainage pipe.

 

[Josh_justJosh]

@Fred26, @Hadders:
Completly missed that, thank you verry much!

 

[malc-c]

I presume that as the consensus is that these are part of the drainage system that might explain the white sheeting on the ground between each of the areas surrounded by guards. Guessing that the black pipe is installed linking them ?

Would love to hear from people who know more about these thing, but I always though points and slips were "pre-made" and dropped into place when needed, if so wouldn't it have been a golden opportunity to have installed the point this weekend whilst the OHLE was moved / replaced or can they slide them in under the wires?

 

[hwl]

I presume that as the consensus is that these are part of the drainage system that might explain the white sheeting on the ground between each of the areas surrounded by guards. Guessing that the black pipe is installed linking them ?

Would love to hear from people who know more about these thing, but I always though points and slips were "pre-made" and dropped into place when needed, if so wouldn't it have been a golden opportunity to have installed the point this weekend whilst the OHLE was moved / replaced or can they slide them in under the wires?

Indeed the black pipe links them.

With the signal recontrol, the idea was to avoid other signalling work.

Points and crossing can easily be installed /replaced under OHLE and usually done with a Kirow Crane, but there are only 6? in the UK. 2 were in use for Newark Crossing replacement, 1 at Kings Cross in the tunnels lifting old track where the new points will go in the future, allowing the ballast to be replaced and temporary new track installed in the gaps to allow quick points installs later or installing the points (a mix of the 2 occuring).

The Kings Cross Twitter feed has a lot of good photos in this regard (inc Stevenage)

Pics of the Kirows at Newark under wires:
https://pbs.twimg.com/media/EC3wouEXUAATJk2?format=jpg&name=large
https://pbs.twimg.com/media/EC0ZYk9WwAUeWfp?format=jpg&name=large

Pic of One of the S&C carrier wagons at Belle Isle looking south into the Gas Work tunnels:
https://pbs.twimg.com/media/EC151mKXUAECoRB?format=jpg&name=4096x4096

Pic of track replacement in gas works tunnels:
https://pbs.twimg.com/media/ECwjX2_XkAAneP0?format=jpg&name=large
https://pbs.twimg.com/media/ECwjZ0pXUAgrpC8?format=jpg&name=large

 

[edwin_m]

There are standards limiting the time a new point can be in place without connecting it to the signalling, and signalling changes probably become easier after the recontrol. If the existing point on the Down Slow is retained, then like the remaining OLE changes inserting the new one on the Down Hertford should be possible with closure of only the Down Hertford and Down Slow, the Down Fast and Up lines remaining open. This is much easier to arrange than a total closure of the route.

 

[Mcq]

There are standards limiting the time a new point can be in place without connecting it to the signalling, and signalling changes probably become easier after the recontrol. If the existing point on the Down Slow is retained, then like the remaining OLE changes inserting the new one on the Down Hertford should be possible with closure of only the Down Hertford and Down Slow, the Down Fast and Up lines remaining open. This is much easier to arrange than a total closure of the route.

That's the explanation I was after - thanks very much.

 

[Ediswan]

They run at weekends and bank holidays as there are less train using the mainline.

And, according to the NR Journey Planner, a few of the very first and last services on weekdays.

 

[malc-c]

There are standards limiting the time a new point can be in place without connecting it to the signalling, and signalling changes probably become easier after the recontrol. If the existing point on the Down Slow is retained, then like the remaining OLE changes inserting the new one on the Down Hertford should be possible with closure of only the Down Hertford and Down Slow, the Down Fast and Up lines remaining open. This is much easier to arrange than a total closure of the route.

Thanks for the info. I'm 100% certain that the exiting point for the Hertford line to join the Down Slow line will remain. A lot of freight gets routed along the Hertford line so as not to hold up trains on the main ECML at the bottleneck caused by Welwyn North tunnels, station and the Digswell viaduct. It also provides relief lines should any work / incidents take place between Stevenage and Bounds Green area. I couldn't see them removing that point and effectively isolating the Hertford loop

 

[edwin_m]

Thanks for the info. I'm 100% certain that the exiting point for the Hertford line to join the Down Slow line will remain. A lot of freight gets routed along the Hertford line so as not to hold up trains on the main ECML at the bottleneck caused by Welwyn North tunnels, station and the Digswell viaduct. It also provides relief lines should any work / incidents take place between Stevenage and Bounds Green area. I couldn't see them removing that point and effectively isolating the Hertford loop

I may not have been completely clear here. I agree there are many reasons why a train from Hertford should be able to continue north of Stevenage instead of just terminating in the new platform, even if no passenger train is scheduled to do so. My point (sorry!) was whether the existing turnout where the Down Hertford joins the Down Slow will remain as it is, or be replaced by a new one possibly in a different position but fulfilling the same role.

 

[adamedwards]

I may not have been completely clear here. I agree there are many reasons why a train from Hertford should be able to continue north of Stevenage instead of just terminating in the new platform, even if no passenger train is scheduled to do so. My point (sorry!) was whether the existing turnout where the Down Hertford joins the Down Slow will remain as it is, or be replaced by a new one possibly in a different position but fulfilling the same role.

I assume the trade off is cost of signalling alterations on the down slow versus any benefit of moving the junction closer to the south end of Stevenage station. I'm guessing the extra half mile of Hertford line doesn't justify the cost of moving the points and signalling.

 

[edwin_m]

I assume the trade off is cost of signalling alterations on the down slow versus any benefit of moving the junction closer to the south end of Stevenage station. I'm guessing the extra half mile of Hertford line doesn't justify the cost of moving the points and signalling.

The signalling alterations would be similar either way but keeping the existing turnout avoids the cost of a new one. However I'm not sure what benefit results from moving the junction nearer to Stevenage. A Hertford train using the existing platform might save a few seconds with the speed restricted junction closer to the station stop, and on turning back would vacate the Down Slow a bit sooner, but these are the trains that will use the new bay platform instead.

 

[jyte]

Nice to see from your videos malc-c that some OHLE upgrades are also taking place (even if they're a necessity to actually install the new alignment).

 

[malc-c]

Nice to see from your videos malc-c that some OHLE upgrades are also taking place (even if they're a necessity to actually install the new alignment).

Not so much of an update, but whilst I was filming the two charters at the weekend work on the site continued with trenches being dug for ducting etc

 

[malc-c]

A further update from today. It's coming along nicely. Looking at the path the ducting is following, our earlier assumptions as to where the new point may go looks like they may well be correct.