East Coast Mainline Blockade for Werrington Junction diveunder

[iands]

There is also quite a few route miles of simbids on Tyneside IECC control area (soon to be transfered to York ROC if not already done so). 

[PenrithBeacon]

IIRC much of the track out of London Bridge (in both directions) is bi-directional as is the elevated section of the MSJ&A in Manchester. I think there are lots of bi-directional working particularly in metropolitan areas, which is why I thought I'd misunderstood in my post above

[rodent279]

1 hour ago, caradoc said:

 

There are indeed, but far too few, particularly on key routes such as the WCML, as per my post above.

 

In Scotland the Glasgow/Ayr route between Elderslie and Kilwinning had bi-di signalling installed when resignalled to Paisley SC, along with electrification, in 1986, invaluable during disruption, even though a full service cannot be operated, and used occasionally on the night shift during engineering work. Bi-di working has now been extended from Elderslie right through Paisley, including on all three lines between there and Shields Jc !

 

There is also a section of the ECML signalled for bi-di working between Innerwick and Grantshouse, on one occasion we used this (at the request of the freight operator) to allow one freight to overtake another, with neither having to stop ! Probably not possible nowadays however, with increased passenger service on the route.

 

I think bi-directional running is much more common on the European mainland, especially in Germany, and also used more on a daily basis. Over here, it seems to be used during engineering works only, except in approaches to large stations such as New St, London Bridge etc.

[iands]

2 hours ago, iands said:

There is also quite a few route miles of simbids on Tyneside IECC control area (soon to be transfered to York ROC if not already done so). 

Just checked, more bi-directional route miles than I thought, effectively from Northallerton to Berwick on ECML, distance of nearly 150 miles although not under the control of one signal box/IECC (yet!). Not sure, but there may also be a fairly short section of about 7 miles between Granthouse and Innerwick.

Effectively only used in the “Wrong Direction” for planned engineering work on the adjoining line, an emergency when a line is blocked due to a failed train, broken rail etc., or to allow other trains to pass when rail grinding in operation. 

[The Stationmaster]

1 hour ago, iands said:

Just checked, more bi-directional route miles than I thought, effectively from Northallerton to Berwick on ECML, distance of nearly 150 miles although not under the control of one signal box/IECC (yet!). Not sure, but there may also be a fairly short section of about 7 miles between Granthouse and Innerwick.

Effectively only used in the “Wrong Direction” for planned engineering work on the adjoining line, an emergency when a line is blocked due to a failed train, broken rail etc., or to allow other trains to pass when rail grinding in operation. 

Is it bi-directional or is it reversible or simbids?   There are essential differences between these systems which stretch back to various safety concerns which prevented the original WR reversible signalling installations being used as bi-directional and then led to reversible being binned in favour of the much cheaper simbids which did away, in effect with comprehensive bi-directional capacity inherent in the original reversible installations.

 

The the early imposition of the restriction of 'wrong direction' line speed was really the first factor factor in killing it as bidirectional system and was very much linked with safety concerns regarding staff working on and about the line.  This led to an early undertaking from WR management, anxious to get the scheme into use, not to use reversible signalling as bi-directional signalling although of course there was already plenty of bi-directional signalling in use in station areas albeit at much lower speeds.  With a system effectively watered down by various safety concerns (some of which were definitely ill-founded although some weren't) it made a lot of sense to do a cheaper job and devise simbids as what was basically mechanised Single Line Working and nothing more.  Although oddly  a stretch of the former WR where the wrong direction signalling is more simbids than reversible is actually permitted to be used as bi-directional signalling

 

So the definitions -

Bi-directional signalled lines may be used at normal line speed by trains in either direction at any time.  Masses of it at larger stations and termini around Britain.  Trains may run on any line at any time, without prior arrangement or notice, and right hand (or wrong line) running can occur thus faster trains my use the bi-directional facility to overtake slower trains.

Reversible signalling was originally devised, and signalled accordingly, to allow a line to be used in the wrong direction at normal line speed in the event of perturbation or for Single Line working but the signalling spec actually accommodated full bi-directional running at normal line speeds (and was no doubt what the specifiers and designers had hoped to introduce).

Simbids (simplified bidirection signalling) is basically no more than mechanised Single Line Working with reduced linespeed in the reverse direction in most cases and intended to provide a far cheaper perturbation oriented system than reversible  or normal bodirectional signalling.

[DY444]

3 hours ago, PenrithBeacon said:

IIRC much of the track out of London Bridge (in both directions) is bi-directional as is the elevated section of the MSJ&A in Manchester. I think there are lots of bi-directional working particularly in metropolitan areas, which is why I thought I'd misunderstood in my post above

 

Not really that much at London Bridge.  In the old layout there was only one reversible line on the SE side which was line No2 and only one on the central side between Spa Road and Bricklayers Arms.

 

The new layout has a bit more but still only on 5 out of 11 lines inwards from Spa Road.

[melmerby]

The up line through Dawlish is bi-directional and is used

[iands]

1 hour ago, The Stationmaster said:

Is it bi-directional or is it reversible or simbids?   There are essential differences between these systems which stretch back to various safety concerns which prevented the original WR reversible signalling installations being used as bi-directional and then led to reversible being binned in favour of the much cheaper simbids which did away, in effect with comprehensive bi-directional capacity inherent in the original reversible installations.

 

The the early imposition of the restriction of 'wrong direction' line speed was really the first factor factor in killing it as bidirectional system and was very much linked with safety concerns regarding staff working on and about the line.  This led to an early undertaking from WR management, anxious to get the scheme into use, not to use reversible signalling as bi-directional signalling although of course there was already plenty of bi-directional signalling in use in station areas albeit at much lower speeds.  With a system effectively watered down by various safety concerns (some of which were definitely ill-founded although some weren't) it made a lot of sense to do a cheaper job and devise simbids as what was basically mechanised Single Line Working and nothing more.  Although oddly  a stretch of the former WR where the wrong direction signalling is more simbids than reversible is actually permitted to be used as bi-directional signalling

 

So the definitions -

Bi-directional signalled lines may be used at normal line speed by trains in either direction at any time.  Masses of it at larger stations and termini around Britain.  Trains may run on any line at any time, without prior arrangement or notice, and right hand (or wrong line) running can occur thus faster trains my use the bi-directional facility to overtake slower trains.

Reversible signalling was originally devised, and signalled accordingly, to allow a line to be used in the wrong direction at normal line speed in the event of perturbation or for Single Line working but the signalling spec actually accommodated full bi-directional running at normal line speeds (and was no doubt what the specifiers and designers had hoped to introduce).

Simbids (simplified bidirection signalling) is basically no more than mechanised Single Line Working with reduced linespeed in the reverse direction in most cases and intended to provide a far cheaper perturbation oriented system than reversible  or normal bodirectional signalling.

Hi Mike, 

The various sections are "simbids", max speed in "wrong direction" being 50mph, sorry should have made the clear in my previous post. However, you may not then have provided the detailed explanations of the differences in "bi-directional" systems which I find most useful, thanks. 

Edited April 9, 2020 by iands
Spell check

[Ken.W]

On 05/04/2020 at 18:59, Donington Road said:

 

Here are some photos of the signals taken last year.

The original is certainly suffering from a bit of rust rot and the ladder looks a bit iffy.

 

 

 

Hi,

That's definately the original signal still in use, with the "new" 4-aspect LED type replacement behind which was installed many years ago but has never been brought into use.

 

On 08/04/2020 at 19:58, Mike Storey said:

Similarly, Bi-Di signals (for routine use) were installed on the ECML in the 1980's, between Peterborough and Huntingdon, but were never used for many years, although they have been utilised subsequently under the drastically reduced requirements of SIMBIDs operation.

 

Erm no, there's been no bi-directional signaling brought into use on the main line between Peterborough and Huntingdon. There is an Up direction signal on the Down at Holme which has never been in use.

The only bi-direction working's wrong direction moves from Peterborough Station to Fletton to access the Nene Valley line

 

23 hours ago, PenrithBeacon said:

There are locations for bi-directional working in the UK, or perhaps I've misunderstood?

 

There's actually a section, not yet mentioned, at the subject of this thread.

Peterborough Station over the Up Slow to Werrington Jn. It allows a train having arrived from Lincoln in the Up platforms to return wrong direction avoiding crossing the main lines twice.

At Werrington it only gives access to the 'Joint Line', down main line trains have to cross back proper line at New England North.

 

13 hours ago, caradoc said:

There is also a section of the ECML signalled for bi-di working between Innerwick and Grantshouse, on one occasion we used this (at the request of the freight operator) to allow one freight to overtake another, with neither having to stop ! Probably not possible nowadays however, with increased passenger service on the route.

 

Now that section, actually Cockburnspath bank, is definately an odd one.

Both lines are signaled bi-directionally, however;

the Down direction over the Up Line (downhill) is SIMBIDS only,

while the Up direction over the Down Line (uphill) is fully bi-directional.

It used to be quite common, with the 21.00 off Edinburgh (the Aberdeen -Leeds) to pass a freight up the bank that was running the same direction wrong line.

That section also seems unusual in that the Up direction bi-di signals are normally green, and you see then changing down as a down train approaches.

 

12 hours ago, iands said:

There is also quite a few route miles of simbids on Tyneside IECC control area (soon to be transfered to York ROC if not already done so). 

 

Yes the full section of the ECML under Tyneside IECC is bi-directional, also Morpeth, Alnmouth, and Tweedmouth signaling areas. So that gives bi-directional operation from Northallerton Station Jn (ie not through Northallerton Station in the down direction, or from the end of the Down Slow at Longlands Jn. about two miles south) right though to Berwick  station.

Again, although Tweedmouth has got bi-directional signals north of Berwick, there's none over the border so no bi-directionals possible north of the station, other than into the Up Goods Loop.

Although it is mostly SIMBIDS, there are also sections of full bi-directional, including Darlington station, the Down Slow from Birtley Jn and then all lines from Low Fell Jn, through Newcastle as far as Benton Jn, also Wooden Gates to (but not through) Alnmouth station for terminating trains, and between Tweedmouth and Berwick station.

[caradoc]

When the Cathcart SB area was re-controlled to the West of Scotland SC, some useful operational improvements were made to the signalling; For example, crossovers previously worked from Ground Frames (eg Muirend) became Signaller-operated, and main aspect signals were provided for turn back moves, eg at Pollokshields East and Cathcart. In addition, the Up (towards) Neilston line was signalled for Down direction moves from Whitecraigs to Muirend, where the Down line was regained by the crossover mentioned above. However......one of the first times that facility was used was when I was travelling home off the night shift, the service was disrupted and my train was terminated at Whitecraigs, dumping me off in the cold ! I was not a fan of bi-di working that day, at least......

 

[melmerby]

9 hours ago, Ken.W said:

 

There's actually a section, not yet mentioned, at the subject of this thread.

Peterborough Station over the Up Slow to Werrington Jn. It allows a train having arrived from Lincoln in the Up platforms to return wrong direction avoiding crossing the main lines twice.

At Werrington it only gives access to the 'Joint Line', down main line trains have to cross back proper line at New England North.

 

I did mention the Down junction signal on the Up slow right near the start of the query on signalling, which has caused this thread to veer off course somewhat.

That's what started the swerve.

 

 

[Crun]

Good Friday bike ride to drop food and milk at my parent's house.  Looking south from Hurn Road bridge. A bit of earth moving activity on the dive under near Werrington Junction:

 

Edited April 11, 2020 by Crun

[Crun]

More sheet piling has gone in since last weekend:

[Crun]

The excavation for Werrington Brook has been nearly covered over:

[Crun]

A closer version of the previous view:

Edited April 10, 2020 by Crun

[Crun]

A view of some tall cylinders/tubes I haven't seen before:

Edited April 11, 2020 by Crun

[Crun]

A side view of the nearly completed work on the Werrington Brook:

Edited April 11, 2020 by Crun

[Crun]

Another photograph of the completed work on Werrington Brook:

Edited April 11, 2020 by Crun

[Crun]

Another view of the work over Werrington Brook:

[Crun]

A view of the newly added sheet piling looking NW across the ECML:

[Crun]

A wide angle view of the ECML and the progress of the sheet piling work:

Edited April 11, 2020 by Crun

[Donington Road]

Thank you for all the updated photos Chris.

The spoil coming out at Hurn Road will probably be from the tunnelling of the two guide tunnels at the northern portal.

[Mike Storey]

19 hours ago, Ken.W said:

 

 

Erm no, there's been no bi-directional signaling brought into use on the main line between Peterborough and Huntingdon. There is an Up direction signal on the Down at Holme which has never been in use.

The only bi-direction working's wrong direction moves from Peterborough Station to Fletton to access the Nene Valley line

 

 

I did not say they had been brought into use (in fact, the complete opposite), but they were definitely installed - I was a Piltoman on part of the works, and was told exactly what the work was for.

 

Whether all or some, or one, has been used subsequently for SIMBIDS, I can only guess, having left Operations on the ECML in the late 80's. They may even have been removed. The fact that one BiDi signal remains at Holme, suggests that, and that would be all that is needed for SIMBIDS on that stretch.

[jamie92208]

Thanks for the photos of the works. It's good to see that work is continuing. Just a point about the cylindrical piles.  What I think you are seeing is the cylinders that cut the holes. IIRC from when a similar process was used at Dover, the metal tube is used to drill the hole, then an auger us used to get the spoil out. Next  a pre made rebar cage us lowered in. The hole is then filled with concrete and the metal tube withdrawn.  All by the same remarkable machine.  I may be barking up the wrong tree and would be happy to be corrected.  Please keep thevpictures coming.

 

Jamie

[Ken.W]

On 08/04/2020 at 19:58, Mike Storey said:

Similarly, Bi-Di signals (for routine use) were installed on the ECML in the 1980's, between Peterborough and Huntingdon, but were never used for many years, although they have been utilised subsequently under the drastically reduced requirements of SIMBIDs operation.

 

20 hours ago, Ken.W said:

Erm no, there's been no bi-directional signaling brought into use on the main line between Peterborough and Huntingdon. There is an Up direction signal on the Down at Holme which has never been in use.

 

1 hour ago, Mike Storey said:

 

I did not say they had been brought into use (in fact, the complete opposite), but they were definitely installed - I was a Piltoman on part of the works, and was told exactly what the work was for.

 

Whether all or some, or one, has been used subsequently for SIMBIDS, I can only guess, having left Operations on the ECML in the late 80's. They may even have been removed. The fact that one BiDi signal remains at Holme, suggests that, and that would be all that is needed for SIMBIDS on that stretch.

Hi Mike,

Sorry if it wasn't  clear, but in saying there's been no bi-directional signaling brought into use on that section, I was meaning any bi-directional, including SIMBIDS.

The remaining signal at Holme has as I said never been in use, and in fact, I don't recall any other bi-direction signals ever actually being installed in that section.

I signed the route, btw, from 1990 until leaving last October