La Belle Sauvage (once again, Holborn Viaduct)

[TJ52]

Keeping just the single slip would provide some extra movements of empty stock etc so might be fun. Possibly more fun the building the double slip!

 

Terry

[Lacathedrale]

I guess I can always run or not run those empty movements with the connection in place, but I can't choose to run them without it!

 

I've also deciphered the plan, @TJ52 and realised that as a 1:10 slip the diamond MUST be switched,

 

1:10 with a fixed K-crossing - note the MASSIVE gap - part of the reason why the prototype never used fixed crossings above 1:8!

 

1:10 with a movable k-crossing. An extra pair of tie bars need to be fitted, adjacent the centre timber.

 

So overall, quite a complicated piece of track that 4/5 destinations on my layout must traverse, so worth getting right...

[Lacathedrale]

I've printed out the revised plan, and it looks really nice - there's no noticeable S-curve on the route from the up-main to P3 and overall I think it looks quite nice!

 

View from P1/2, pilot shed on the right looking towrds the throat

 

View from the signal gantry approaching the station

 

Overall view showing the full extent of the  throat board - approx 3'6"

 

One thing that has been on my mind is the notional plan I was working on for an urban terminus with @justin1985 - albeit set in a cutting. I've been delving through old photographs of Moorgate. I mean, just look at this and tell me it's not the scenic break between the throat and the station platforms:

 

Moorgate Street Station, circa 1960's?

 

By building the track on a separate board it could be mounted into a viaduct or at the base of a cutting. On one hand, stations-on-viaducts are basically my bread and butter - having commuted through London Bridge, Waterloo East, Charing Cross and Cannon Street - but it does make construction and maintenance significantly more difficult. A hybrid of Moorgate's setting and HV's track plan is a simple pivot, imagining Holborn Viaduct as an outgrowth of the low-level widened lines station, instead of way above ground level.

 

An aerial photo from the post-war era shows the station nestled in amongs road bridges and surrounded by large buildings, etc.

 

Moorgate Street Station, circa 1947 showing bomb damage

 

In layout form, the cutting could be omitted from the viewing side except for supports for road bridges similar to what you see here.

 

Edited September 16, 2020 by Lacathedrale

[burgundy]

Modelling 1947, you would not have many buildings to worry about. It would also be rather a poignant reminder of a less privileged period of history.

Best wishes 

Eric

[Lacathedrale]

An interesting idea. For now my time scale is fairly elastic at roughly 1910-1955 for the layout, and the location is potentially now somewhat elastic too - either part of the LCDR Metropolitan Extension, or the actual HV location, or somewhere further east on the ELR. I suppose for now it doesn't matter!

 

Moorgate Street, Platform 6 circa 1910 showing the arrangement of canopies and platform furniture

 

The blitz-era illustrate why the station ended up looking quite so austere:

 

Moorgate St towards the buffer stops of P5 and 6

 

Moorgate Street towards the throat. The leftmost bridge arch is the same as shown in the pre-group photo above

 

I think I'd rather go with Edwardian splendour, all told!

 

[Mikkel]

Edwardian would be great - though I have to say the brownish shades in that 1960s(?) shot of Moorgate  are pretty nice too. Although I suppose the film may have exaggerated them.

 

9 hours ago, Lacathedrale said:

 

Moorgate Street Station, circa 1960's?

 

 

[justin1985]

18 hours ago, Mikkel said:

Edwardian would be great - though I have to say the brownish shades in that 1960s(?) shot of Moorgate  are pretty nice too. Although I suppose the film may have exaggerated them.

 

 

 

So much brown! 

 

I had lazily assumed the Met went straight from varnished teak to cheerful LT red - I guess we're looking at their equivalent of "LNER Teak Brown paint"? 

[Lacathedrale]

Is the unit behind the brown one in LT red? I do like the cast of the photo - it certainly has that evocative tone of sizzling tar, heat radiating brick and  dust.

[croydon junction]

1 minute ago, Lacathedrale said:

Is the unit behind the brown one in LT red? I do like the cast of the photo - it certainly has that evocative tone of sizzling tar, heat radiating brick and  dust.

by the looks of it it is. Think its F stock from the district by the looks of it

[Lacathedrale]

Well, as per some posts in the 2mmFS thread, some vees have been filed:

 

 

and some timbers laid:

 

 

One more around the sun....

 

 

[Lacathedrale]

Going through my layout plan, I realised that although the track flowed nicely, I had inadvertently ended up with a  number of wye turnouts of a low crossing angle, 1:6 and 1:7. The resultant radius was still large, but is not a true reflection of prototype practise.

 

The reason for this was that when setting the plan out, I created the entrance and exit points, then created links between them. I inserted turnouts as neccesary using straight branch tracks and more links to join it all together. I had not paid real attention to the curvature insofar that as long as it was at a reasonable minimum radius and crossing angle - I was satisfied.

 

Checking the plain to ensure I had the right jigs and materials, I discovered the issue - and happily it only took about 10 minutes to fix. The solution was to keep my datum points in place, i.e. the entrance of the throat, and the platform roads, and delete the track and turnouts between. I then inserted plain track and re-created simple links in the directions required for the 'main' roads, and then turned those into turnouts and used the branch track > geometry - straight > create simple link with the new formations.

 

A picture may better illustrate the difference:

 

Before:

 

After:

 

I realise this probably doesn't look like much from the outside, but essentially everything left of the double slip has been re-drawn and re-aligned, now all running lines are using C10 turnouts that are straight or curved - no bloody wyes - and I think it flows even more nicely.

 

Thoughts on a postcard?

 

[martin_wynne]

Hi William,

 

I think your first plan flowed better -- EXCEPT that you hadn't changed to curviform V-crossings where you had contraflexures.

 

Generally you need to do that for Y-turnouts (Wye is a river ), unless they are part of a curved double-track crossover.

 

More about all that in this video:

 

 https://flashbackconnect.com/Movie.aspx?id=pu2F-wveux5-EWGYuqPd3g2

 

cheers,

 

Martin.

[Lacathedrale]

Ah, that's helpful, thank you.

 

That said, I think part of the reason the flow was broken was the use of perfectly straight turnouts to replace the wyes (to avoid, contraflexure (lovely word!)). By gently curving them I feel that the flow has been restored

 

 

I think that on balance the use of 1:10 turnouts that are curved normally is more appealing to me than the use of 1:7 wyes.

[Nearholmer]

Point-work as deliberate art?

 

Perhaps book a gallery at the Tate Modern.

 

I’m sure that with words like contraflexure and sinuosity, and much mumbo-jumbo about the symbolism of it all, a catalogue could be put together.

[Lacathedrale]

Printed out, it's quite hard to distinguish the plans - which do you prefer, left or right?

 

 

The plan with primarily C10 turnouts is on the left - but other than turnouts shifting around a little bit on P1 and P4 and he centre pair of turnouts being smoothed out - I do think that there's really not much in it at all, and so am erring on the side of the left plan just for the simplicity of straight or curved turnouts rather than contraflexed (love it).

 

Edited September 22, 2020 by Lacathedrale

[KeithHC]

I will just sit here and drool over both. One day I will pluck up the courage to have a go at track building the sight of flowing curves just makes it look right.

 

Keith

[martin_wynne]

Hi William,

 

There is no logic to regarding turnouts with similar flexure as ok, but those with contraflexure as not ok. On the prototype each is a common as the other.

 

I think you will find when constructed that dead straight turnouts within otherwise curving tracks will be noticeable and give a set-track effect.

 

The problem with your original plan is not that some turnouts have contraflexure, but that those turnouts do not have curviform V-crossings. It is important to choose between a regular and curviform V-crossing every single time you create a template in Templot. That's why there is a quick-click green indicator at the top left of the screen. More info here:

 

 https://flashbackconnect.com/Movie.aspx?id=pu2F-wveux5-EWGYuqPd3g2

 

cheers,

 

Martin.

[Lacathedrale]

Thanks Martin, i will check out the curviform v-crossing settings now. @KeithHC you really should give it a shot - there is no magic bullet or time when you will feel ready. I still feel very unready, but it's just another skill to learn and with the help of Templot and @martin_wynne alot of the hard work is done for you.

 

@justin1985 suggested I simulate some stock movements, so I dug out my lone star models - bought pointlessly (ha!) a few months ago - and hopefully give you a taste of the layout with some stock to scale it:

Queenboro' boat train pulls out of P2, after the arrival of the Dover Mail in P3. A suburban tank trundles into P4

 

The Up Cathedrals Express draws into P4 while a clapped out tank pulls a stopping service to Central Croydon

 

What I thought most interesting however, was taking a picture from the loco-shed side (i.e. what was meant to be the back of the plan) and I think it might end up being more pleasing overall:

 

Queenboro' boat train pulls out of P2, after the arrival of the Dover Mail in P3. A suburban tank trundles into P4 (seen from the north)

 

The Up Cathedrals Express draws into P4 while a clapped out tank pulls a stopping service to Central Croydon (seen from the north)

 

Without the widened lines delving below, the layout does seem more naturally viewed from the north. Any thoughts?

[bbishop]

Lacathdrale, just a thought, but  you could extend the headshunt from P1 and join it to the down line.    That would let you depart from P1 whilst arriving at any other platform.  You would need advanced starters so you can use it as a headshunt whilst departing P2 - 4.   Bill

[Lacathedrale]

@bbishop hello there! That is actually a loco spur and and engine shed, as pictured at the right of this photo:

 

 

The plan has been heavily simplified from the original HV layout - the 1916 edition of a 50" to 1mi shows a much more complicated arrangement that I have broadly outlined in green on my plan below. There is an additional spur for coal wagons, as well as an outside single slip to access the loco shed, as well as a pilot siding at the end of Platform 3/4 (pretty much where the photographer is standing in the above shot). To facilitate better simultaneous movements there's another layer of crosovers for P3-6 from the up main, too.

 

Here's a scan that was infront of me the whole time, that I never stumbled across before now - which shows the station at its maximum extent:

 

 

The fact that there is what looks like Brio-level turnout  right by the throat does make me question the geometry, but it does hopefully show the correct connections, and some of the most complicated pointwork I think any of us would ever wish to see.

 

I've tried tracing this out with Templot and it's almost impossible! It seems that the LCDR really did want to get their moneys worth on land purchase - no less than three tandem turnouts, all of which are connected to either half-scissors or outside single slips! My very limited ability to decode this trackplan has resulted in this, just out of interest:

 

 

To clear it up in my own mind, here are my amendments effected on the plan:

 

 

The obvious change is the removal of the second route through the throat to allow simultaneous departures and arrives, to be replaced with a double slip on the entrance.  Another other change is that around platform 1 and the engine shed area - by shifting the shed across one road, it drastically simplifies a hellish combination of double-sided tandem turnouts and a slip with no operational impact. Similarly, the omission of (what was originally) P5 is driven more by trying to understand what value it adds.

 

I'll give it a quick bash to see what the 'restored' throat looks like - but I won't be slavishly copying the 50" OS grid map - it's too far out there even for me!

 

 

Edited September 23, 2020 by Lacathedrale

[bbishop]

William,  I can remember Holborn Viaduct from the early 1960s, from my Wednesday afternoon loco spotting trips.  The first generation SUBs had just gone so it was an EPB from Catford.  If it was an 8 coach train, entry to platform 1 was very slow with the buffers practically kissing to clear the track circuit at the country end.  Platform 6 had gone by then, so there were three electrified platforms with the short platforms 2 & 3 for the newspaper traffic?

 

Off peak traffic was Catford loop to Sevenoaks and ex LSWR to Sutton.  Additional peak was Orpington via Penge and semi fast to Sheerness or Maidstone East.  Short workings were to Kent House and Shortlands (Catford loop only) and to Bickley for berthing.  I don't recollect any Bellingham services, were those sidings used for overnight berthing?  Or was a schoolboy changing at Shortlands, Bromley South or Bickley uninterested in a Bellingham train?  Of course there were three terminal platforms at Blackfriars for peak services.  Only the Catford Loop to Sevenoaks had a different code - 67 rather than 83.

 

Your plan has any movement other than an arrival in platform 4 making use of the double slip so rather restricting the throat.  My suggestion would provide more flexibility, but of course this is irrelevant if you are operating solo.

 

Bill

[Lacathedrale]

Thanks Bill, I've no memory of HV, but certainly trains around Catford  

 

After finding the 1896-1916 plan above, I was unable to stop myself from interpreting it in a plan...

Edited September 24, 2020 by Lacathedrale

[Lacathedrale]

I decided I wasn't going to let it beat me, so I laid out the track plan more precisely - same length:

 

 

The plan above is now exactly as per the prototype albeit with more reasonable curvature than the OS map suggests, with a minimum radius of 22" on some of the curved turnouts.

 

It looks quite hellish to build at first glance, even though it is more eased than the prototype appeared to be (!!!). Broken down however, the pointwork consists of:

• A Regular crossover
• A Crossover into a diamond
• Three Crossovers into a single slips
• Two Tandem turnouts
• One regular turnout

As before, I think it requires some mulling before any further decisions are made.

 

 

[bbishop]

William,  the problem now is platform 5, which blocks everything other than a platform 6 arrival.  Looking at the 'Brio' sketch, is the crossover actually a single slip?  Bill

[Lacathedrale]

Ah yes, could be right!

 

Your point about the double-slip being a pinch-point did highlight the benefit of using a prototypical track plan - there's no need to second guess it (drunken surveyors aside). I think we can safely assume the people who designed stations as their day job knew exactly how to lay things out properly. It IS a large increase in track plan scope however.  Side by side, the additional complexity is quite evident.

 

Holborn Viaduct Stylised (left) vs 1896-1916 (right)

 

It's quite evident how P1 and P6 are fairly simple 'bolt on' components to the stylised plan, as are the pilot siding and additional sidings by the engine shed. If you take a 10,000' view, the one thing the prototype plan brings to the table that's objectively superior to the stylised plan is the additional lane in the throat, the rest is just window dressing. I've done some calculations of source/destination in a matrix format to determine how important that is.  The 1896-1916 plan's extra lane allows simultaneous departures and arrivals from all non mutually-exclusive destinations, as well as allowing a pilot loco to shunt P1-4 without affecting P3-6 or vice versa. The only movement which is simultaneous on the stylised plan is an arrival to P4, which can occur while other platforms are shunted or there are departures.

 

How important this is, is up for debate.

 

In the meantime, here's a few photos with my lone star stalwarts:

 

Across the bows

 

 

I didn't know it would be possible for an A4 to look swamped

 

An eight carriage express rolls in

 

 

Edited September 24, 2020 by Lacathedrale