Track design

[Ianno87]

No. Loco changing was done, but sub optimally, reducing the capacity of Preston station as a whole.

== Doublepost prevention - post automatically merged: 10 Jan 2021 ==

So which trains could not fit in the timetable because of the necessary engine changes at Preston eating up capacity?

 

[furnessvale]

So which trains could not fit in the timetable because of the necessary engine changes at Preston eating up capacity?

You want me to produce a notional timetable from 1976 indicating which trains had to be removed due to lack of capacity? No can do.

What I can say is that, at the time, we were told the new track layout was designed to accommodate 80% of the trains currently running, as that was the estimated requirement for trains going forward.

After remodelling, it was demonstrated that 80% of the trains that previously ran were now running, thus proving the accuracy of the previous estimates! Such are the policies/economics (call it what you will) of the madhouse.

 

[Dr Hoo]

Surely the point was that certain flows were disappearing anyway - such as the collapse of traditional business to Blackpool in the face of foreign holidays; some flows were handled more efficiently - such as the improved traction and braking capabilities of electrification and air-braked liner trains meaning fewer trains for the same tonnage and faster throughput; and others were diverted - such as residual un-fitted freights diverted over the Settle & Carlisle from south of Preston station.

It really would have been the 'economics of the madhouse' to essentially replicate the steam age manually-signalled layout with colour lights when some of it wasn't needed any more.

 

[Ianno87]

You want me to produce a notional timetable from 1976 indicating which trains had to be removed due to lack of capacity? No can do.

What I can say is that, at the time, we were told the new track layout was designed to accommodate 80% of the trains currently running, as that was the estimated requirement for trains going forward.

After remodelling, it was demonstrated that 80% of the trains that previously ran were now running, thus proving the accuracy of the previous estimates! Such are the policies/economics (call it what you will) of the madhouse.

In other words, the layout successfully accommodated the level of service it was designed for.

 

[Joseph_Locke]

No. Loco changing was done, but sub optimally, reducing the capacity of Preston station as a whole.

== Doublepost prevention - post automatically merged: 10 Jan 2021 ==


Nasty cough you've got there Joseph. Of course those lines are NOW electrified, as I mentioned in my post, 40 years later. Meanwhile, for most of those 40 years loco changing was a sub optimal process eating into station capacity.

My bad, read your post too fast to get all the words!

Anyway, I can confirm that the 1976 view of the world turned out to be good for another 20 years in terms of decline in traffic. Crewe remdelling was done on a similar basis, hence it's troubles today. It wasn't until late into the 90s that the industry woke up to the fact that the trend had definitely reversed and we started planning for growth instead of shrinkage.

As to loco-changing, optimally efiicient loco-changing is a pretty low bar, IMHO, if nt an oxymoron altogether?

 

[furnessvale]

In other words, the layout successfully accommodated the level of service it was designed for.

It could hardly have accommodated any more, so less trains ran! Cause and effect?

 

[Ianno87]

It could hardly have accommodated any more, so less trains ran! Cause and effect?

Fundamentally the same layout has accommodated all the various service increases from the mid-1990s to the present day.

 

[172007]

Leamington Spa suffers from the rationalisation at the north end. Services coming from Warwick can't access bay platform 1 and also platform 2. On the full non Covid timetable some trains have to shunt over from platforms 3 & 4 to 1 & 2; using both North and South options. Simply too much stuff tries to terminate in platform 4 during the rush hour shoulders with a lot of traffic also passing through 3.

 

[furnessvale]

Fundamentally the same layout has accommodated all the various service increases from the mid-1990s to the present day.

Most of those increases involve MUs. There is no way of knowing just what services never saw the light of day in the late 1970s-1980s due to restrictions on loco changing and other restrictions caused by the remodelling.

It has to be remembered that "making the services fit the layout" included things like removal of Blackpool to London services.

 

[Dr Hoo]

Most of those increases involve MUs. There is no way of knowing just what services never saw the light of day in the late 1970s-1980s due to restrictions on loco changing and other restrictions caused by the remodelling.

It has to be remembered that "making the services fit the layout" included things like removal of Blackpool to London services.

I really can't let comments like this pass unchallenged. A quick check of the 1976 timetable (after the electrified WCML timetable had settled down) confirmed my recollection. For example, a normal weekday morning in Preston:

0941 Liverpool Lime Street-Glasgow Central. Arr 1033, changes traction, departs 1041
0956 Manchester Victoria-Glasgow Central and Edinburgh. Arr 1040, changes traction, departs 1048
0800 Euston-Blackpool North. Arr 1058, changes traction, departs 1107
0800 Glasgow Central-Manchester Vic and Liverpool Lime Street. Arr 1040, changes traction on front portion, departs for Manchester at 1051.
Fresh locomotive then attached to rear portion and departs for Liverpool at 1059.

How on earth could five trains be dealt with like this in around half an hour if...

A remodelling of Preston in the early 1970s allowed for no engine movements for loco changing on Blackpool, Liverpool and Manchester trains

?

 

[Ianno87]

It has to be remembered that "making the services fit the layout" included things like removal of Blackpool to London services.

That was, what? A full 15 years after the remodelling? And driven by the economics of the service to Blackpool, not lack of capability to operate it.

 

[furnessvale]

I really can't let comments like this pass unchallenged. A quick check of the 1976 timetable (after the electrified WCML timetable had settled down) confirmed my recollection. For example, a normal weekday morning in Preston:

0941 Liverpool Lime Street-Glasgow Central. Arr 1033, changes traction, departs 1041
0956 Manchester Victoria-Glasgow Central and Edinburgh. Arr 1040, changes traction, departs 1048
0800 Euston-Blackpool North. Arr 1058, changes traction, departs 1107
0800 Glasgow Central-Manchester Vic and Liverpool Lime Street. Arr 1040, changes traction on front portion, departs for Manchester at 1051.
Fresh locomotive then attached to rear portion and departs for Liverpool at 1059.

How on earth could five trains be dealt with like this in around half an hour if...

?

It would appear that my recollections are wrong. My only defence is that by the time the scheme was completed I had left the Preston drawing office for pastures new.

Maybe a few extra crossovers were slipped into the scheme at the last minute when it was realised that electrification wasn't going to happen.

 

[Joseph_Locke]

It would appear that my recollections are wrong. My only defence is that by the time the scheme was completed I had left the Preston drawing office for pastures new.

Maybe a few extra crossovers were slipped into the scheme at the last minute when it was realised that electrification wasn't going to happen.

At the north end of Preston? No small re-design, that.

 

[snowball]

Around the time the electrification of Weaver Junction to Glasgow was completed I used to do 6-8 round trips per year between Manchester and Edinburgh. I always found it frustrating that changing locomotives at Preston took so long, cancelling much of the time gains elsewhere.

I also bought a copy (which I probably still have somewhere) of the book "Electric Euston to Glasgow" by O.S. Nock. If I remember correctly, Nock compares the layout at Preston unfavourably with that at Crewe, criticising the lack of features to facilitate quick and easy locomotive changing, such as the handily-placed shunting necks that then existed at Crewe. Perhaps this is the point furnessvale intended to make.

In the first years after electrification there were morning Manchester-Glasgow and Liverpool-Edinburgh trains allowing cross-platform interchange at Preston. However, with both having to change locomotives, the time from the arrival of the first to the departure of the second was horrendous. Nock in his book suggested reducing this a bit by switching the Liverpool one onto the down slow at Balshaw Lane, allowing (he claimed) simultaneous arrival of both trains at platforms 3 and 4. However, if he had studied the track layouts in his own book, he would have seen that this parallel movement is not provided for.

 

[Ianno87]

Around the time the electrification of the northern WCML was completed I used to do 6-8 round trips per year between Manchester and Edinburgh. I always found it frustrating that changing locomotives at Preston took so long, cancelling much of the time gains elsewhere.

I also bought a copy (which I probably still have somewhere) of the book "Electric Euston to Glasgow" by O.S. Nock. If I remember correctly, Nock compares the layout at Preston unfavourably with that at Crewe, criticising the lack of features to facilitate quick and easy locomotive changing, such as the handily-placed shunting necks that then existed at Crewe. Perhaps this is the point furnessvale intended to make.

Although at the time it was probably expected that Manchester/Liverpool electrification would have followed quickly in the subsequent years negating the need for loco changes...which then proved not to be the case.

 

[furnessvale]

Although at the time it was probably expected that Manchester/Liverpool electrification would have followed quickly in the subsequent years negating the need for loco changes...which then proved not to be the case.

Isn't that what I said in #22?

 

[Ianno87]

Isn't that what I said in #22?

Yes, but the loco changes could still happen, just a bit less elegantly.

 

[Dr Hoo]

Well, I've re-skimmed Nock's book and found no reference to problems at Preston such as Snowball describes. Perhaps there was a second edition (?) as the first one was published before the overall scheme was completed in May 1974.

The simplification of Preston was described in terms of "the work has not been extensive". The main benefits were bi-directional working through all platforms and raising the speed limit from 15mph to 35mph (which only benefitted freight as practically all passenger trains called) through elimination of redundant connections. (The LMR was never very wised up on parallel working as I will readily concede.)

The Crewe layout was, of course, not really changed for electrification in the early 1960s so all of the complex paintwork (and its painfully low speeds) remained by default.

I agree that the general 'so near yet so far' perception of a locomotive change not far from Manchester, Liverpool or Blackpool wasn't ideal but I still stand by my conclusion that a station that could handle five locomotive changes, each within around eight minutes, in the space of half an hour was hardly un-equipped for the task.

 

[CW2]

In my experience, Preston in the 80s / 90s usually worked pretty well, although it was quite labour intensive.
In later years when dealing with WCML sleeper diversions (dragging) it got worse, with fewer staff and lack of regular practice at loco changing.
Crewe remains an issue. To go back to the original post, your starting point must be to consult and agree as to what you are trying to achieve. In the case of Crewe, the insistence on having as fast as possible fast lines through the middle of the station causes delays to the 95+% of traffic which is scheduled to call. So I would say:

1) Agree with your stakeholders what you are trying to achieve, and how this will be measured.
2) Make a personal site visit, and talk to the local staff, gathering their views and ideas.
3) Draw up a basic track plan, with speeds and distances included. Involve a P.Way designer in this, if you can.
4) Include a signalling engineer at this stage, and modify track layout as required.
5) Reiterate steps 3 and 4 until you are satisfied. Add layers of detailed design with each iteration.
6) Present to stakeholders. Obtain feedback.
7) See step 5.
8) Obtain a decent cost estimate based on the most recent design. (Have the smelling salts ready when presenting to stakeholders).
9) Be prepared to modify scheme in light of excessive costs. (Costs are ALWAYS "excessive").

 

[snowball]

Well, I've re-skimmed Nock's book and found no reference to problems at Preston such as Snowball describes. Perhaps there was a second edition (?) as the first one was published before the overall scheme was completed in May 1974.

I'll try to find my copy. I'm fairly sure it said the things I mentioned. I don't think I have a later edition. My copy is full of pre-wiring photographs, perhaps due to the time it took to produce a book in those days. I think it was written late enough that he had had sight of the post-May-1974 timetable.

 

[furnessvale]

Yes, but the loco changes could still happen, just a bit less elegantly.

Exactly what I said in #30.

 

[Inversnecky]

Here’s one for the railway modellers to try!

Farringdon

 

[172007]

Here’s one for the railway modellers to try!

Farringdon

View attachment 91075

Reminds me on Bearley Jct near Stratford OA. The junctions diamond crossing actually had point blades within it as the angle was tight; it was not a slip, only worked as a diamond.

 

[Bald Rick]

Reminds me on Bearley Jct near Stratford OA. The junctions diamond crossing actually had point blades within it as the angle was tight; it was not a slip, only worked as a diamond.

A switch diamond? Pretty common (or were, there are fewer of them around these days).

 

[Inversnecky]

A switch diamond? Pretty common (or were, there are fewer of them around these days).

I'd read switch diamonds were not considered very favourably.

 

[Bald Rick]

I'd read switch diamonds were not considered very favourably.

They’re not! At least not now.

 

[Cheshire Scot]

Going back to loco changes on the 'new' 1970's layout at Preston it is worth noting in addition to the Liv/Man to Scotland trains (6 per day I think?) the enhanced May 74 WCML electric timetable included five trains per day from Euston to Blackpool, once a day the Ulster express to Heysham to connect with the night boat to Belfast, and for Barrow the overnight from Euston plus a portion detached off the 18.05 Euston to Carlisle, all of these requiring diesel traction north from Preston, and similar southbound workings, meaning traction changes were happening at Preston throughout the day. Plus, to keep things interesting the Barrow sleeper conveyed a Preston sleeping car which got parked in the short north end bay to await a civilised hour to alight.

 

[Annetts key]

Are there any informative resources about track design (thinking of in urban areas and station vicinities)? How switches, slips and crossings are organised and laid out? Are the more complex elements built are required, or do they generally simpler if space allows?

As a child I was always amazed at the complexity on some routes. And wondered if there was a ‘design manual’.

As stated above, there are various documents.

Officially track layouts (especially junctions, complex station areas and other complex areas) are supposed to be designed after discussions between the relevant train operator(s) (both passenger and freight), Network Rail operations, the Permanent Way engineering section, the Signalling engineering section, if relevant, the overhead line (OHL) or third rail engineering section, and if relevant the structure engineering section.

Factory made track panels are the preferred method of construction at the moment. Whereas in the past, bespoke designs constructed on site were sometimes used to fit a more complex layout in.

The overall cost of the design is a very big factor, so wherever the cost can be reduced by simplifying the layout, this will take place. Hence single lead junctions with standard crossovers having displaced more traditional junction layouts.

As well as the very practical consideration of fitting points and crossings in to the layout. Clearances, overlaps, standing room, braking distances all have to be considered during the design of the signalling system. As does the positioning of the signals.

And if if the line is electrified or due to be electrified, the relevant infrastructure (e.g. the poles, masts etc.) all have to be considered.

If there is a level crossing, the highways authority may also need to be consulted.

So it can be a very complex task.

Each engineering section has its own documentation on the requirements in a design.

 

[The Planner]

As stated above, there are various documents.

Officially track layouts (especially junctions, complex station areas and other complex areas) are supposed to be designed after discussions between the relevant train operator(s) (both passenger and freight), Network Rail operations, the Permanent Way engineering section, the Signalling engineering section, if relevant, the overhead line (OHL) or third rail engineering section, and if relevant the structure engineering section.

Factory made track panels are the preferred method of construction at the moment. Whereas in the past, bespoke designs constructed on site were sometimes used to fit a more complex layout in.

The overall cost of the design is a very big factor, so wherever the cost can be reduced by simplifying the layout, this will take place. Hence single lead junctions with standard crossovers having displaced more traditional junction layouts.

As well as the very practical consideration of fitting points and crossings in to the layout. Clearances, overlaps, standing room, braking distances all have to be considered during the design of the signalling system. As does the positioning of the signals.

And if if the line is electrified or due to be electrified, the relevant infrastructure (e.g. the poles, masts etc.) all have to be considered.

If there is a level crossing, the highways authority may also need to be consulted.

So it can be a very complex task.

Each engineering section has its own documentation on the requirements in a design.

And train planning, many an occasion in the past where we have been forgotten, things have developed and a sponsor gets a bit upset when we say "that doesn't deliver the timetable"

 

[edwin_m]

And train planning, many an occasion in the past where we have been forgotten, things have developed and a sponsor gets a bit upset when we say "that doesn't deliver the timetable"

Or someone comes up with an operational requirement they hadn't thought of before, that throws everything back to square 1.