GWR Quadrouple Lines.

[Methuselah]

Years ago, the main GWR line both north and south of Snow Hill was quadroupled, and most, but not all of the intermediate stations had at least four platforms. There was a main Up and Down, and next to that, seperate slow/goods/refief Up & Down lines.Did the GWR always follow that pattern, or did they sometimes run both Up lines next to each other and both Down lines next to each other....?

 

Did the other 'Big Four' have a set approach/policy to how they laid-out quadroupled lines with regard to the traffic directions....?

 

Have modern practices changed in regards to this issue...?

[WillCav]

The GWR used both methods - UDUD for example from Cogload Jn through Taunton and beyond. UUDD Ladbroke Grove to Didcot.

Will

edit: UUDD at Cogload and UDUD at Ladbroke grove (oops)

Edited May 4, 2020 by WillCav
Being wrong- very wrong

[Methuselah]

19 minutes ago, WillCav said:

The GWR used both methods - UDUD for example from Cogload Jn through Taunton and beyond. UUDD Ladbroke Grove to Didcot.

Will

 Yes - this is why I asked, as it seems a rather odd approach, as it could potentially cause confusion for drivers - it was bad enough with drivers on the right and signals on the left..... I wonder what the GWR's rationale was......

[Pete the Elaner]

I think most applications preceded the big four, but there are advantages & disadvantages of each layout.

[WillCav]

UUDD is better for trains swapping between main and relief with no opposing trains getting in the way.  It is also better for passengers if two island platforms are provided - one for both ups and one for both downs.

UDUD is better for engineering work as you can close mains, run on reliefs or vice versa if you don't need all four lines. It also has a smaller footprint as only one wide way 10' required.

If you want to swap from one type to the other,  you can with a flyover as at Bishton.

Will

[Siberian Snooper]

2 hours ago, WillCav said:

The GWR used both methods - UDUD for example from Cogload Jn through Taunton and beyond. UUDD Ladbroke Grove to Didcot.

Will

 

I think you will find that between Ladbroke Grove and Didcot it's  Down Main, Up Main, Down Relief and Up Relief. Between Cogload and Norton Fitzwarren was Down Relief, Down Main, Up Main and Up Relief.

Between Bentley Heath and Moor Street was as Cogload - Norton Fitzwarren.

 

 

[Pete the Elaner]

2 hours ago, WillCav said:

UUDD is better for trains swapping between main and relief with no opposing trains getting in the way.  It is also better for passengers if two island platforms are provided - one for both ups and one for both downs.

UDUD is better for engineering work as you can close mains, run on reliefs or vice versa if you don't need all four lines. It also has a smaller footprint as only one wide way 10' required.

If you want to swap from one type to the other,  you can with a flyover as at Bishton.

Will

 

UDUD allows lines to diverge without an expensive flyover. It also allows trains to reverse more easily, whether heading off to a yard to be stored or (probably a modern application), terminating on a line between up & down.

10' way was not universal (but may be on newer lines). The southern section of WCML is 6' between all 4 lines.

[Zomboid]

10 minutes ago, Pete the Elaner said:

UDUD allows lines to diverge without an expensive flyover.

Only if it's acceptable to have a flat junction on one pair of lines. Of course a flat junction is possible on either configuration, as Didcot and Woking prove. Which is "better" really depends on the type of traffic, junctions etc, both have advantages and disadvantages depending on the situation.

 

I think UDUD is more common in the London area, but in other parts of the country I think UUDD might be the more likely arrangement.

[Trog]

One thing that is for certain is that having both options in the same geographic area is dangerous for the staff. As if you are used to one arrangement then work on the other, your instinctual reactions can lead you into danger.

[jim.snowdon]

5 minutes ago, Trog said:

One thing that is for certain is that having both options in the same geographic area is dangerous for the staff. As if you are used to one arrangement then work on the other, your instinctual reactions can lead you into danger.

I wouldn't disagree with the common sense logic of that, but within the London area, there are the examples of the BML, which is UDUD from Waterloo to Wimbledon, then UUDD all the way to Basingstoke (Worting Junction). The Brighton main line is UDUD all the way to Victoria, except for the line to London Bridge, which is UUDD.

It's the sort of thing that was probably far less of a problem in the days when gangs were more confined to their own areas than it is these days when contract staff end up all over the place.

 

Jim

[Bomag]

38 minutes ago, Trog said:

One thing that is for certain is that having both options in the same geographic area is dangerous for the staff. As if you are used to one arrangement then work on the other, your instinctual reactions can lead you into danger.

 

It's no different than if lines were bi-directional; for any section of track you are on you need to know where there nearest place of safety is and the lateral safety zone you need to allow for. On any of the multiple track sections I surveyed I always chose the datum rail from the line between the one being surveyed and the cess, it meant the chainman (or myself if using a laser level) had nor more that one full line to cross.

[Compound2632]

It does depend upon how the quadrupling came about. On the Midland main line out of St Pancras as far as Glendon South Junction, the line capacity was increased by adding a parallel set of goods lines that in some places went their own way to get easier gradients, the original line having been built a bit on the cheap - so UDUD. In other places, widening was more piecemeal - a running loop on one side being extended to join up with another, and so forth - so UUDD evolved. 

[Pete the Elaner]

1 hour ago, Zomboid said:

Only if it's acceptable to have a flat junction on one pair of lines. Of course a flat junction is possible on either configuration, as Didcot and Woking prove. Which is "better" really depends on the type of traffic, junctions etc, both have advantages and disadvantages depending on the situation.

 

I think UDUD is more common in the London area, but in other parts of the country I think UUDD might be the more likely arrangement.

 

Sort of.

In the WCML's case, the slow lines are already the correct side for Northampton, so they just split at Roade. The nearest junction is several miles away. The junctions are only used for trains to swap between fast & slow lines.

 

Shenfield on the GE is another matter. The Southend lines are on the wrong side so the down has a dive under but the up line has to cross the Norwich lines.

This may sound crazy but I believe it is because the stabling yards at Shenfield & Gidea Park on on the north side of the line & it is probably not possible to move them.

Gidea Park is unusual because the down Southend line passes through the yard, which allows trains to reverse without having to cross any lines.

 

1 hour ago, Zomboid said:

 

I think UDUD is more common in the London area, but in other parts of the country I think UUDD might be the more likely arrangement.

 

Quite probably. The first 3 examples I am most familiar with are the WCML from Euston to Roade, the GE from Liverpool St to Shenfield & the GW out of Paddington.

[melmerby]

Crewe station on the WCML has different formations each side

South of the station it is UDUD with the fasts on the East side, north it is UUDD.

North of York, at Skelton Junction, the ECML formation changes from UDUD to UUDD

[Methuselah]

     Thanks for all that info'. It seems that today there is quite a mixture everywhere. Actually - I hadn't even considered the safety of gangs on he line - a good point - but it all seems to have great potential to confuse drivers. Logically, you'd have expected there to be some sort of national standard - especially after two hundred years..... :-). I wonder if the issue has ever caused any accidents...?

     There certainly seems a balance of logic for UUDD on the face of it, as the fast traffic is away from the margins, and the slow lines can access sidings etc more easily.

[Trog]

7 hours ago, Methuselah said:

    ....................................

   I wonder if the issue has ever caused any accidents...?

  There certainly seems a balance of logic for UUDD on the face of it, as the fast traffic is away from the margins, and the slow lines can access sidings etc more easily.

 

I was on a site where a member of staff presumably confused the UF with the DS being more used to DUDU which we did most of our work on, and walked under a slow moving UF train.

 

As for accessing sidings with DUDU you can have both slow lines adjacent to a single yard, and would need to cross the fasts to access sidings less often. It also helps separate fast and slow services as a reversing train does not need to cross the fasts to reach the other slow line, which would increase line capacity by reducing conflicts. 

[jim.snowdon]

7 hours ago, Methuselah said:

     Thanks for all that info'. It seems that today there is quite a mixture everywhere. Actually - I hadn't even considered the safety of gangs on he line - a good point - but it all seems to have great potential to confuse drivers. Logically, you'd have expected there to be some sort of national standard - especially after two hundred years..... :-). I wonder if the issue has ever caused any accidents...?

     There certainly seems a balance of logic for UUDD on the face of it, as the fast traffic is away from the margins, and the slow lines can access sidings etc more easily.

A major disadvantage of the UUDD arrangement is that when you want to work on the fast lines and keep trains running, the worksite is surrounded by operational lines. Access to and from the cess is more difficult, as is working with machines (under current NR rules for Adjacent Line Open working, it becomes all but impossible). In today's safety environment (whatever you may think about it), having the two sets of lines as parallel double track railways, ie UD+UD, is far easier. It would be the way to build a new railway, but, what we have is the result of past widening of double track railways, in a past era when both working practices and safety considerations were very different. Changing that would be a very expensive exercise for minimal gain. It has been done, but there are very few instances, and those were to solve mounting operational problems with an existing layout.

 

Jim

[WillCav]

13 hours ago, Siberian Snooper said:

 

I think you will find that between Ladbroke Grove and Didcot it's  Down Main, Up Main, Down Relief and Up Relief. Between Cogload and Norton Fitzwarren was Down Relief, Down Main, Up Main and Up Relief.

Between Bentley Heath and Moor Street was as Cogload - Norton Fitzwarren.

 

 

Snooper - you're absolutely right - I know what I MEANT to write but what I typed was totally opposite!

Many Thanks

Will

[GlenPudzeoch]

Of course the Northon Fitzwarren accident in WW2 was on a line  which was/is UUDD and the driver misread the signals (much mitigating factors) .  Always a hazard with UUDD.

 

 

[Pete the Elaner]

9 hours ago, Methuselah said:

Logically, you'd have expected there to be some sort of national standard - especially after two hundred years..... :-). I wonder if the issue has ever caused any accidents...?

 

 

Adopting a standard would require changing from 1 to the other at many places. This would involve changing the layout of track & platforms at many stations which only serve trains on the slow/relief lines, junction changes, storage yard re-designs, possibly also new flyovers & lots of re-timetabling work.

[jim.snowdon]

When you consider that what are now four track lines were created by widening existing (and operational) railways, without stopping the services, it probably couldn't be done these days with the number of safety "rules" imposed on  constructors and designers.

 

Jim

[melmerby]

9 hours ago, Methuselah said:

    

     There certainly seems a balance of logic for UUDD on the face of it, as the fast traffic is away from the margins, and the slow lines can access sidings etc more easily.

Except on the WCML From Rugby to Brinklow where, looking north, it is DF-DS-UF-US.

 

(Following that there is section where there is only one down line before reaching Attleborough from whence all the way to Colwich Jn it is DS-DF-UF-US, and several stations only have platforms on the slow lines)

[LMS2968]

27 minutes ago, Pete the Elaner said:

 

Adopting a standard would require changing from 1 to the other at many places. This would involve changing the layout of track & platforms at many stations which only serve trains on the slow/relief lines, junction changes, storage yard re-designs, possibly also new flyovers & lots of re-timetabling work.

The section eastward out of Lime Street was originally US-DS-UF-DF until preparation for electrification. From 5 September 1960 it became US-UF-DF-DS, which must have involved a few headaches for both PWay and S&T staff.

 

Approaching Wigan from the south it was DS-US-DF-UF. At Bamfurlong Jct things changed, with the Whelley line heading off east to north. North of Wigan it was double track only until the Whelley rejoined at Standish Jct, the Whelley effectively being the Slow lines, even if widely spaced, so the situation we effectively DF-UF-big gap-DS-US, which was the situation at Standish. From here though it became DS-US-DF-UF, requiring some very big crossovers to sort out the various roads.

[The Stationmaster]

12 hours ago, Methuselah said:

     Thanks for all that info'. It seems that today there is quite a mixture everywhere. Actually - I hadn't even considered the safety of gangs on he line - a good point - but it all seems to have great potential to confuse drivers. Logically, you'd have expected there to be some sort of national standard - especially after two hundred years..... :-). I wonder if the issue has ever caused any accidents...?

     There certainly seems a balance of logic for UUDD on the face of it, as the fast traffic is away from the margins, and the slow lines can access sidings etc more easily.

Officially there is (or definitely was not too long back in BR days) a 'preferred arrangement',  and that was pairing by direction, not pairing by use.   I suspect the main reason for it was that in terms of new work it was the cheapest most cost effective way of quadrupling a formation.

 

The Western generally preferred pairing by use but even that had its dangers for those whose work took them around the Company/Region.  A former pal of mine worked in the S&T Dept on telecoms and his work took him all over the place and he always moaned about the difference between the London Division, where the Main lines were on the Down side,  and the quadruple section between Lapworth and Birmingham Moor St where things were the opposite way round and the Mains were on the Up side which made it much easier to be caught out by fast trains.   However when the pairing by direction was altered to pairing by use between Newport and Bishton flyover (where it changed from one to the other) the Mains there were created on the Up side as they were between Cardiff and Newport.

[The Stationmaster]

17 hours ago, Siberian Snooper said:

 

I think you will find that between Ladbroke Grove and Didcot it's  Down Main, Up Main, Down Relief and Up Relief. Between Cogload and Norton Fitzwarren was Down Relief, Down Main, Up Main and Up Relief.

Between Bentley Heath and Moor Street was as Cogload - Norton Fitzwarren.

 

 

My memory is confirmed by a check of the signal box diagrams that Lapworth (where the quadrupling started)  to Moor Street was paired by use, not by direction (although some of it might well have been changed when it was rationalised as part of the Saltley resignalling??).