East-West Rail (EWR): Oxford-Bletchley construction progress

[Dr A.Johnston]

New video from NWP Exploring on YouTube - Progress on EWR

 

[Bald Rick]

It will be interesting to see the position of that track at 1600 on Tuesday.

 

[Ploughman]

Did they initially lay sleepers and rail directly on to the Terram?
Then Tip Stone and Tamp, lifting the track in front of the Tamper or did the Tamper manage to lift enough to avoid puncturing the Fabric?

 

[swt_passenger]

Did they initially lay sleepers and rail directly on to the Terram?
Then Tip Stone and Tamp, lifting the track in front of the Tamper or did the Tamper manage to lift enough to avoid puncturing the Fabric?

Yes. Rail first, then the Balfour Beatty New Track Construction machine adds the sleepers. Then ballast is dropped. It’s how it has been usually working on this project, there's a video in post #549 of how it lays the sleepers, and various photos of it and other trains on ballast-less track a few posts back around that point.

But I think it can also work if there is ballast laid first, other videos of it working at Werrington Junction on new track a while back had it working over a higher ballast depth. The linked video seems to show most ballast removed but I suppose renewals are different again?

 

[Trainee9]

New video from NWP Exploring on YouTube - Progress on EWR

An interesting video showing several of the same views I saw on the 15th. The shots of a ballast train in action dropping ballast on the outskirts of Bletchley (where both tracks are already laid) are particularly interesting.

 

[Ploughman]

I understand about the NTC, I worked with it once a number of years back.
My point is that when the track is laid directly onto the Terram, how is the track lifted through the ballast without puncturing the Fabric?
Is it first Tamper pass with a big lift?

 

[swt_passenger]

I understand about the NTC, I worked with it once a number of years back.
My point is that when the track is laid directly onto the Terram, how is the track lifted through the ballast without puncturing the Fabric?
Is it first Tamper pass with a big lift?

Ok sorry, yes I see on a reread that’s really your main question. It does seem risky for the Terram as you say. What sort of depth is the Terram supposed to be on completion of the final alignment?

 

[Nicholas Lewis]

I understand about the NTC, I worked with it once a number of years back.
My point is that when the track is laid directly onto the Terram, how is the track lifted through the ballast without puncturing the Fabric?
Is it first Tamper pass with a big lift?

Yeah i was a bit surprised to read the above and look back at the pictures to see the sleepers laid direct onto the terram. Also the front of the NTC is supported on steel tracks which could also chew up the terram but clearly the client track team are comfortable with the approach.

 

[Nottingham59]

Did they initially lay sleepers and rail directly on to the Terram?

My point is that when the track is laid directly onto the Terram, how is the track lifted through the ballast without puncturing the Fabric?

Can anyone tell me what is the function of the Terram in this instance,please? I see there are lots of different sorts of Terram geotextiles used as trackbed separators at https://terram.com/products/ , but I can't tell what sort is being used here.

What would happen to the track over time if Terram was not used? And given that the fabric is supposed to be permeable, why does it matter if it gets punctured by ballast?

 

[zwk500]

Can anyone tell me what is the function of the Terram in this instance,please? I see there are lots of different sorts of Terram geotextiles used as trackbed separators at https://terram.com/products/ , but I can't tell what sort is being used here.

What would happen to the track over time if Terram was not used? And given that the fabric is supposed to be permeable, why does it matter if it gets punctured by ballast?

It helps stop weeds growing into the ballast and stops the ballast mixing with the soil. The permeability allows water to drain but stops the solid particles moving through. If it were torn by the tamper, you'd have long gashes where the sub ballast could mix into the ground, and over time this would lead to insufficient support and drainage for the track, giving low spots, wet beds, etc.

 

[Nottingham59]

It helps stop weeds growing into the ballast and stops the ballast mixing with the soil. The permeability allows water to drain but stops the solid particles moving through. If it were torn by the tamper, you'd have long gashes where the sub ballast could mix into the ground, and over time this would lead to insufficient support and drainage for the track, giving low spots, wet beds, etc.

Thank you for that explanation. The great thing about these forums is that there is always someone who knows the answer!

 

[zwk500]

Thank you for that explanation. The great thing about these forums is that there is always someone who knows the answer!

I may be wrong, I am familiar with the reasons but don't have any close involvement so there may be other factors. It's a combination of informed guesses, Heritage railway project updates and the fact that terram is very similar to the membranes Gardeners use.
Of course, Terram matting doesn't help with soil and seeds that creep into the ballast from the sides or above (in rain, wind etc), and it degrades over time, which is why lesser maintained lines still have a healthy growth of weeds in the four foot.

 

[Nicholas Lewis]

It helps stop weeds growing into the ballast and stops the ballast mixing with the soil. The permeability allows water to drain but stops the solid particles moving through. If it were torn by the tamper, you'd have long gashes where the sub ballast could mix into the ground, and over time this would lead to insufficient support and drainage for the track, giving low spots, wet beds, etc.

I would surmise on first pass the tamper operator would put on maximum lift (150mm) so the tines are well clear of the Terram product and get a base of ballast under the sleepers then on 2nd pass can fine tune lift and alignment.

 

[Dr A.Johnston]

Latest video from

'Trains,Planes, Phones and Drones ,GRM production' on YouTube as of yesterday

 

[swt_passenger]

Neat update.

From the video it looks as if for the next phase of tracklaying they are starting with bottom ballast laid already as there’s no visible Terram membrane under those rails on the up side that are positioned awaiting sleepers.

Further west a significant length of LWR is present having been delivered into the down line four foot, I wonder if anyone could estimate the length, a couple of km maybe?

I noticed at about 1:30 - 2:40 there seems to be recent activity on the left at the top of the embankment, does that look like ‘crest drainage’ improvements? Presumably bringing that system up to current standards is part of the overall work, I think many of the cuttings on the out of use section were fairly wet when the project began.

 

[Mogz]

Long may it continue!

This line will provide interchange between multiple main lines.

Once it’s all up and running I hope Bletchley becomes a regular stop on the longer distance WCML services to ensure a decent interchange between that line and the MML and later the ECML if the project gets that far!

 

[a good off]

Long may it continue!

This line will provide interchange between multiple main lines.

Once it’s all up and running I hope Bletchley becomes a regular stop on the longer distance WCML services to ensure a decent interchange between that line and the MML and later the ECML if the project gets that far!

It won’t, but Bletchley is only a quick hop on a frequent local service from MKC.

 

[Ploughman]

What is the standard length of a rail ? 235yd / 215m just guessing.
You can see a number of rail ends overlapping by a metre or so.

 

[swt_passenger]

What is the standard length of a rail ? 235yd / 215m just guessing.
You can see a number of rail ends overlapping by a metre or so.

Yes, very close, AIUI the maximum length LWR strings that the delivery train can handle is 216m, which is two of the maximum length that the steelworks produce welded together.

 

[richieb1971]

It won’t, but Bletchley is only a quick hop on a frequent local service from MKC.

Oxford has a direct connection to MKC. Cambridge does not. Only folk from the East need to change at Bletchley. If folk from Oxford catch the Bedford train they will also need to change, but a direct train will run to MKC as well.

 

[cle]

Oxford has a direct connection to MKC. Cambridge does not. Only folk from the East need to change at Bletchley. If folk from Oxford catch the Bedford train they will also need to change, but a direct train will run to MKC as well.

Have they figured out the paths for MKC? I know it is touted as 2tph MKC and 2tph Bedford at launch, all to Oxford - but I understood it wasn’t actually calculated how.

Expecting some shorter turns - the Southern to Watford we know - but maybe another service at Bletchley itself.

 

[Bletchleyite]

Have they figured out the paths for MKC? I know it is touted as 2tph MKC and 2tph Bedford at launch, all to Oxford - but I understood it wasn’t actually calculated how.

Expecting some shorter turns - the Southern to Watford we know - but maybe another service at Bletchley itself.

2 MKC and one Bedford, no?

I would be surprised if the paths hadn't been taken into account in the December recast.

 

[The Planner]

Have they figured out the paths for MKC? I know it is touted as 2tph MKC and 2tph Bedford at launch, all to Oxford - but I understood it wasn’t actually calculated how.

Expecting some shorter turns - the Southern to Watford we know - but maybe another service at Bletchley itself.

2 MKC and one Bedford, no?

I would be surprised if the paths hadn't been taken into account in the December recast.

They exist.

 

[DarloRich]

I know they wont but it would be nice if the Marston Vale train could run into the high level platforms rather than P6. The high level platforms will be more accessible!

Once it’s all up and running I hope Bletchley becomes a regular stop on the longer distance WCML services to ensure a decent interchange between that line and the MML and later the ECML if the project gets that far!

They wont - but E-W passengers will have a direct link to MK where the transfer will happen. Passengers from Bedford will have to change at Bletchley & MK

 

[Tobbes]

They wont - but E-W passengers will have a direct link to MK where the transfer will happen. Passengers from Bedford will have to change at Bletchley & MK

It still seems nuts that the N-E chord at Bletchley isn't being built - why you would force a change to the major local travel generator is unclear to me.

(And let's not talk about the failure to electrify throughout from day one.)

 

[DarloRich]

It still seems nuts that the N-E chord at Bletchley isn't being built - why you would force a change to the major local travel generator is unclear to me.

argh - Kenny, Get me a Zantac!!!!!!!!!!!!

 

[Bletchleyite]

I know they wont but it would be nice if the Marston Vale train could run into the high level platforms rather than P6.

I don't think the Dec 2022 timetable has any Bletchley terminators, and so 6 should be able to be put pretty much out of use and 5 used instead?

If 6 has any future they really should install a lift.

 

[DarloRich]

I don't think the Dec 2022 timetable has any Bletchley terminators, and so 6 should be able to be put pretty much out of use and 5 used instead?

If 6 has any future they really should install a lift.

LNWR wont use P5 at peak time ( for MV services) as it blocks access to the carriage sidings and p6 should have a lift now!

 

[Tobbes]

argh - Kenny, Get me a Zantac!!!!!!!!!!!!

I get that. But nonetheless....

 

[swt_passenger]

I get that. But nonetheless....

This thread was purposely broken out of the original more general thread to concentrate on construction news. I think lack of specific curves is not really a construction issue?