Theory of General Minories

[Pacific231G]

5 hours ago, SZ said:

 

It's 3D view in SCARM.

 

I like it, with two platform roads you have the quick succession of simultaneous arrival/departure, arrival, departure, simultaneous arrival/departure with no 'wrong line' departure from a platform 3 to occupy the signalling block and slow the flow (though it would be interesting to see which version copes better with a tidal flow, is the extra capacity of a platform 3 cancelled out by the 'wrong line' running needed to depart from it?)

 

Interestingly, if you reverse the throat (so that this view looks from the platform end) the 'wrong line' element of departing from platform 2 is completely removed giving a more complete segregation of arrival and departure roads (the arrival and departure 'forks' cross rather than interlace, but this reversal doesn't work for 3 platforms).

 

I'm thinking multiple units but loco-hauled with a new engine trailing in from off scene and the old engine chasing out would work too.

 

With two platform roads you're probably in the territory of  one of the quieter outer suburban termini like Windsor Riverside as it is now (it used to have three as well as a goods and loco depot) or Hampton Court (which once had four but was far busier). The busier ones tend to have three platform roads and if you look at the Hammersmith terminus of the Hammersmith and City line, which was originally a suburban steam terminus, it has a definite Minories flavour about it. Three platform tracks also seem pretty common for a lot of the outer Underground termini like Uxbridge, Ealing Broadway (District), High Barnet etc.  

With any terminus for a double track line,  a train departing from a higher numbered platform will always block arrivals to a lower numbered platform. With Minories an arrival in platform three will block a departure from platform two (but not  from platform one) 

 

It's fairly easy to solve this by adding a connecting track between platform three and the inbound main line but I don't think any of the three platform suburban termini I've quoted actually do that. The reason is that with just three platforms the time it takes for a train to turn around limits the stations total capacity more than congestion in the throat and that's even more true with two platforms. Trains simply can't come in and out frequently enough for arrivals and departures to block one another in the approach.

 

With a two or three platform layout its not uncommmon for incoming trains to get held up waiting for a platform to clear - it happens quite often at Ealing Broadway (District)- but delays seem to be caused by platform occupancy rather than congestion in the throat. However, when you get to five platforms (as at Bastille) or more, the number of trains per hour that the platforms can turn round does require simultaneous arrivals and departures across all platforms so the need for parallel arrivals and departure routes for any two platforms.

 

Model railway operation rather disguises this constraint as our trains can depart immediately after arriving but it takes time for a real train, even a MU, to turn around.

Edited November 19, 2020 by Pacific231G

[RJS1977]

On 16/11/2020 at 09:56, Joseph_Pestell said:

 

Your post reminds me of a layout design point that I have looked at. Many terminus to fiddleyard layouts leave a lot of unscenic length which always seems such a waste at exhibitions. Kings Cross (and no doubt some other locations) gives a perfect solution with a goods yard above fiddleyard/approach tracks to the passenger terminus.

 

Not dissimilar to the pre-war classic Mayfield which had a loco depot over the fiddle yard - indeed I think CJF drew up a plan which combined Minories with Mayfield's loco depot.

[St Enodoc]

2 hours ago, RJS1977 said:

 

Not dissimilar to the pre-war classic Mayfield which had a loco depot over the fiddle yard - indeed I think CJF drew up a plan which combined Minories with Mayfield's loco depot.

Maybank, I think, but your point is well-made.

[Flying Pig]

7 hours ago, Pacific231G said:

It's fairly easy to solve this by adding a connecting track between platform three and the inbound main line

 

An alternative is a single slip at the end of platform 1, providing an additional crossover from platform 2 to the outbound line - effectively a vestigial form of the ladder @KeithMacdonald has been using.  Perhaps neater in appearance, but with the usual caveat of tight radius in the slip if using Streamline track, here affecting departures from platform 1.

[Pacific231G]

2 hours ago, Flying Pig said:

 

An alternative is a single slip at the end of platform 1, providing an additional crossover from platform 2 to the outbound line - effectively a vestigial form of the ladder @KeithMacdonald has been using.  Perhaps neater in appearance, but with the usual caveat of tight radius in the slip if using Streamline track, here affecting departures from platform 1.

I did experiment with single slips while trying to achieve a shorter throat with the same characteristics as Minories but, with the main line coaches I want to use, found that the effective two foot radius was for me a show stopper as the throwover was just too great. Unfortunately, this didn't just apply to Peco, I tried  an SMP slip and it had exactly the same problem. In any case, for the reasons I suggested yesterday, there's not a real benefit in this for a three platform terminus though I have looked at this avoiding line to access the goods arrivals and departures road (platform 3 or preferably a headshunt parallel to it). The avoiding line doesn't add to the overall length of the terminus and has no effect on platforms 1 & 2 but, with three foot radius points (Peco medium),  it does reduce the length of platform 3 by four or five inches. 

 

My own opinion, but based on practical trials, is that, unless you're modelling something like the Underground or a metro with naturally tight radii and short carriages, the Minories design just looks toy like with two foot radius points (or worse still setrack) as the overall reverse curve inherent to the design becomes far too apparent and you'd probably be better off laying the same  operational design with straight crossovers. You will then get a massive throwover between coaches as they negotiate the two crossovers but that won't look so obvious the rest of the time*

 

Conversely, if you lay out Minories with Peco long points, the platforms come too far forward from the main line alignment thanks to Peco's 1:5 or 12 degree divergence angle. It might be interesting though to try it with a slightly shallower crossing such as the no. 6 turnout in the 83 line range with a roughly 10 degree frog/common crossing angle.  I've seen an N gauge Minories laid with shallower angle points (still Peco I think) and it looked fine. 

 

I have come to the conclusion that our modelling ancestors got it right when they settled on three foot as the recommended minimum radius for pointwork in 00/H0 and a good compromise between the more scale length points we'd like to use and the space most of us have available. That, along with a minimum thirty inch curve on plain track, was the BRMSB recommendation and things like Pecoway's cast frog,  other point kits from that time and drawings in MRN etc. were based on it (three foot radius was the largest that the likes of Wrenn and Formoway offered)  Apart from the one route with an immediate reverse curve (inbound-P1) Minories works well with three foot radius points and the throwover on the other five routes is not significantly greater than it is over a single point alone. 

 

*I've just been looking again at photos of the late Andy Hart's "Achaux" layout that for many years "flew the drapeaux" for French outline modelling in Britain. Though he did tell me that his design had been influenced by Minories he used a straight approach and, because he'd based the layout on three foot long boards used two foot radius points (Peco code 100 small). Long main line coaches did indeed rather lurch over the crossovers but the overall effect and sense of space of the layout was very effective. 

 

  . 

 

Edited November 19, 2020 by Pacific231G

[Flying Pig]

15 minutes ago, Pacific231G said:

I've seen an N gauge Minories laid with shallower angle points (still Peco I think) and it looked fine. 

 

I think the divergence angle for code 55 is 10° so slightly shallower than the 00 points.

 

The real solution of course is for us all to buy Hattons four- and six-wheelers

[Joseph_Pestell]

17 minutes ago, Pacific231G said:

I did experiment with single slips while trying to achieve a shorter throat with the same characteristics as Minories but, with the main line coaches I want to use, found that the effective two foot radius was for me a show stopper as the throwover was just too great. Unfortunately, this didn't just apply to Peco, I tried  an SMP slip and it had exactly the same problem. In any case, for the reasons I suggested yesterday, there's not a real benefit in this for a three platform terminus though I have looked at this avoiding line to access the goods arrivals and departures road (platform 3 or preferably a headshunt parallel to it). The avoiding line doesn't add to the overall length of the terminus and has no effect on platforms 1 & 2 but, with three foot radius points (Peco medium),  it does reduce the length of platform 3 by four or five inches. 

 

My own opinion, but based on practical trials, is that, unless you're modelling something like the Underground or a metro with naturally tight radii and short carriages, the Minories design just looks toy like with two foot radius points (or worse still setrack) as the overall reverse curve inherent to the design becomes far too apparent and you'd probably be better off laying the same  operational design with straight crossovers. You will then get a massive throwover between coaches as they negotiate the two crossovers but that won't look so obvious the rest of the time*

 

 

 

 

We can't beat the rules of geometry. Any inside slip point with a reasonable radius is going to be a minimum of 14" long. There are fewer and fewer ready-to-lay options available. Roco had a 10 degree single slip but it has been discontinued.

 

Perhaps we could persuade Wayne at fiNetrax to include an outside slip in his new 00 range.

 

Peco "code 55" pointwork is 10 degree crossing angle as opposed to the 12 degree of H0/00 which is why it looks so much better in operation.

[Joseph_Pestell]

9 minutes ago, Joseph_Pestell said:

 

We can't beat the rules of geometry. Any inside slip point with a reasonable radius is going to be a minimum of 14" long. There are fewer and fewer ready-to-lay options available. Roco had a 10 degree single slip but it has been discontinued.

 

Perhaps we could persuade Wayne at fiNetrax to include an outside slip in his new 00 range.

 

Peco "code 55" pointwork is 10 degree crossing angle as opposed to the 12 degree of H0/00 which is why it looks so much better in operation.

Just checked out the Roco. Reference no is 42591. Still some available new (€55) and also s/h on eBay. Radius is claimed to be 959mm (37.5") and 345mm long, although it could be cut down by about 2".

[Chimer]

Going back to 2 v 3 platforms, if you have 3 the simultaneous arrival and departure can be followed in short order by another departure.  If you only have two, you have to (well, the real world has to) allow time for the "arrived" train to disembark and reembark passengers before it can leave again.  So I reckon the third platform probably gives a greater than 50% increase in capacity, certainly so if you include the extra track allowing platforms 2 & 3 to do the simultaneous trick.

[RobinofLoxley]

8 hours ago, Chimer said:

Going back to 2 v 3 platforms, if you have 3 the simultaneous arrival and departure can be followed in short order by another departure.  If you only have two, you have to (well, the real world has to) allow time for the "arrived" train to disembark and re-embark passengers before it can leave again.  So I reckon the third platform probably gives a greater than 50% increase in capacity, certainly so if you include the extra track allowing platforms 2 & 3 to do the simultaneous trick.

From what I can very vaguely remember as a young lad cruising the tube network, the 3 track terminii worked off mainly 2 track working in quiet periods, lets say T2 and T3. Trains going out of service arrived into T1 and then departed empty for sidings or shed. This kind of working was facilitated by having 2 island platforms with T2 in the centre having the arriving train discharge to one side then open the opposite side for departing passengers. Very quick turnarounds at the likes of Cockfosters were done like that; if you were coming down the stairs or short escalator to platform level and passengers were coming through the turnstiles, it was best to run if you didnt want to wait the 10 mins for the next one. I think almost all the deep line termini were like that, as well as others further in that were termini earlier in the build, like Arnos Grove, Finchley Central, etc.

[RJS1977]

9 hours ago, Chimer said:

Going back to 2 v 3 platforms, if you have 3 the simultaneous arrival and departure can be followed in short order by another departure.  If you only have two, you have to (well, the real world has to) allow time for the "arrived" train to disembark and reembark passengers before it can leave again.  So I reckon the third platform probably gives a greater than 50% increase in capacity, certainly so if you include the extra track allowing platforms 2 & 3 to do the simultaneous trick.

I'm a little unsure of that - it seems to involve more trains departing than arriving!

[Pacific231G]

11 hours ago, Chimer said:

Going back to 2 v 3 platforms, if you have 3 the simultaneous arrival and departure can be followed in short order by another departure.  If you only have two, you have to (well, the real world has to) allow time for the "arrived" train to disembark and reembark passengers before it can leave again.  So I reckon the third platform probably gives a greater than 50% increase in capacity, certainly so if you include the extra track allowing platforms 2 & 3 to do the simultaneous trick.

I think that with either two or three platforms the factor limiting capacity per hour will be the time each train needs to be at the platform not the maximum flow rate through the throat. As the number of platforms increases the throat design becomes more critical because you will start needng more simultaneous arrivals and departures.

 

The maximum rate of arrivals and departures is going to be the  time T each train needs to be on the platform plus the time it actually takes to traverse the throat and enter or leave the platform (ta and td) divided by the number of platforms ((T+ta+td)/P)  so if say ta and td are both 2 minutes and platform dwell time is five minutes (which is quite short)  then, for a two platform terminus, the flow rate is going to be a train every four and a half minutes and I don't think trains arriving on alternate platforms with every other move requiring a crossover would tax the signalling system  too much. for three platforms  the flow rate rises to a train every three minutes. With a three platform minories type throat  without an extra track to platform three, one in three arrivals and two in three departures will require a crossover move. so an average of half the movements, meaning a crossover move every three minutes, again not too taxing for the signallers. 

At Bastille, or any of the London commuter termini, it will be (or was) the orgin or departure station for the vast majority of rush hour passengers so you can "flight" trains essentially with a bunch of arrivals (most of them ECS for the evening rush) followed, with some overlap,  by a bunch or departures for different destinations either on diverging lines or by arranging trains to run non stop to a certain point on the line then stop at every statiion to their terminus with the final train in the group stopping at the innermost stations and terminating at some intermediate point.  You then repeat that cycle as many times as necessary until  the rush hours are over then breath a sigh of relief.

For something like a London Underground or Tyne Metro terminus it's a bit more tricky because you ideally want trains to run trains at regular intervals with arrivals and departures equally spaced out but LUL makes judicious use of turnround stations. On the tube line I use most often they're at White City, North Acton and Northolt, so you can run a more intensive service in the centre without overloading the outer termini which, in the case of the Central Line's West Ruislip "branch" only has a single island platform.  

Edited November 20, 2020 by Pacific231G

[Pacific231G]

14 hours ago, Joseph_Pestell said:

 

We can't beat the rules of geometry. Any inside slip point with a reasonable radius is going to be a minimum of 14" long. There are fewer and fewer ready-to-lay options available. Roco had a 10 degree single slip but it has been discontinued.

 

Perhaps we could persuade Wayne at fiNetrax to include an outside slip in his new 00 range.

 

Peco "code 55" pointwork is 10 degree crossing angle as opposed to the 12 degree of H0/00 which is why it looks so much better in operation.

Peco do have a no. 6 (9.5 degree frog) double slip in their code 83 North American range and it does look a lot more elegant than the Streamline version. It's 306mm (12 inches) long compared with 249mm (9.8 inches) for the Streamline slips.

[Keith Addenbrooke]

10 hours ago, RJS1977 said:

I'm a little unsure of that - it seems to involve more trains departing than arriving!

It’s the evening rush hour

[Titanius Anglesmith]

8 hours ago, Pacific231G said:

On the tube line I use most often they're at White City, North Acton and Northolt, so you can run a more intensive service in the centre without overloading the outer termini which, in the case of the Central Line's West Ruislip "branch" only has a single island platform.  

 

West Ruislip was originally planned as having three platforms but for whatever reason the third platform was never built.  The platform track however was laid and is used as a siding.  Evidence of the missing platform can be seen in the staff bridge at the London-end.  The metal stairs on that side end at platform height, and there's three or four concrete steps at the foot to make up the gap.

 

A similar thinning of the service happens at the east end with trains reversing at Loughton and Debden on the Epping branch, and at Newbury Park and Hainault on the loop.

[Zomboid]

That kind of thing is pretty common on tube lines. The jubilee turns trains back at North Greenwich and Willesden Green, The District at West Ham, Barking and Dagenham East, and so on. I'm not sure where they finish, but not every train on the Piccadilly goes to Cockfosters (Arnos Grove?)...

[Pacific231G]

On 18/11/2020 at 23:53, RJS1977 said:

 

Not dissimilar to the pre-war classic Mayfield which had a loco depot over the fiddle yard - indeed I think CJF drew up a plan which combined Minories with Mayfield's loco depot.

CJF's version is Peco copyright but here is the plan of  original O gauge Maybank from an article about the layout in MRN in August 1934 . It's probably one of the least remembered but most influential layouts of all time and almost certainly the first fully developed terminus to fiddle yard layout ever built.

 

It was based on an imagined GCR secondary main line terminus and built by Bill Banwell and Frank Applegate. They didn't have room in O gauge for the then conventional roundey -round so they built it n 1932-1933,  on four "portable" six foot long baseboards and two longer baseboards for the storage unit and the MPD above it, in a long narrow ladder shed that Banwell's father, a retired builder, was no longer using. It was first exhibited at a hobby show in Wealdstone in 1932 (Note their MRC badges)

 

and at the MRC Easter show in the following and all but one subsequent years until the war.

The high level good yard behind the station also appeared at the MRC show in 1933 but seems to have been abandoned thereafter.

 

This was 1934

and this was at the MRC show in 1937

Unfortunately Maybank didn't survive the blitz but Bill Banwell's post war Maycroft was a garden railway that appeared several times at the MRC Easter show  (work that one out! ) .

 

Unlike modellers such as Peter Denny, John Charman, Frank Dyer, Philip Hancock and of course John Ahern, Bill Banwell and Frank Applegate weren't really into writing about their modelling- I've only ever seen two short articles by Bill Banwell- so weren't well known beyond those who knew them personally and of course O gauge was eclipsed by smaller scales after the war.  However, both men were clearly extremely accomplished modellers from a very young age- Their track and rolling stock was all scratch built and the pointwork wasn't exactly simple. The "storage sidings" were based on a semi-automatic motorised "traverser" - actually a sector plate.

Minories was definitely inspired by Maybank, we know that because CJF said so and had seen it before the war as I suspect had Peter Denny. In any case they were all MRC members and, having been rather in awe of them as a child,  CJF described them both as friends. 

Edited November 29, 2020 by Pacific231G
correction of baseboard lengths

[simon b]

I drew up a plan inspired by Clive Mortimer's Sheffield exchange mk1. It puts the approach pointwork on a curve to fit in the space I had available, and by using the Tillig single slip avoids the sharp angle of the Peco item. The only thing I wasn't sure of is the loco siding being a facing point on the up line, but trying to put it anywhere else involves takes too much space. Platforms are 5ft long which will take 4 mk1 suburban coaches and a class 31 at either end.

 

 

 

This is the tillig slip in question.

Edited November 20, 2020 by simon b
Info added

[Lacathedrale]

@Pacific231G - some shots of Maybank I hadn't seen before, lovely stuff. Honestly, combined with my sojourn into tinplate it really feelsl ike the apex of terminus-to-FY operations, but that might be through the lense of rose tinted glasses!

[Satan's Goldfish]

On 20/11/2020 at 22:05, simon b said:

I drew up a plan inspired by Clive Mortimer's Sheffield exchange mk1. It puts the approach pointwork on a curve to fit in the space I had available, and by using the Tillig single slip avoids the sharp angle of the Peco item. The only thing I wasn't sure of is the loco siding being a facing point on the up line, but trying to put it anywhere else involves takes too much space. Platforms are 5ft long which will take 4 mk1 suburban coaches and a class 31 at either end.

 

 

 

This is the tillig slip in question.

 

 

Not the most artistic doodling, but how's about changing which tracks the platforms are between and adding the loco siding as a trailing connection to the departure line?

 

[Pacific231G]

On 29/11/2020 at 11:41, Lacathedrale said:

@Pacific231G - some shots of Maybank I hadn't seen before, lovely stuff. Honestly, combined with my sojourn into tinplate it really feelsl ike the apex of terminus-to-FY operations, but that might be through the lense of rose tinted glasses!

Well, more like the beginning than the Apex. Cyril Freezer described Maybank as "the first of the moderns "  Apart from a few railway company display layouts going back before the First World War, the only other layout I know of from before the Second World War that used an off-stage "fiddle" or staging yard was Aldo Cosomati's Alheeba State Railway. That was also one of the first if not the very first layout to have as much scenery as railway and was acknowledged by John Ahern as having inspired him to do the same- though not to use hidden sidings. Terminus to fiddle yard operation didn't really come into its own until after the war. 

I think the reason why Bill Banwell and Frank Applegate built it that way was because the only suitable space they had available was the long narrow shed, though the possibilities of exhibiting it may have also been a motivation. In those days almost nobody was interested in branch lines or light railways and Maybank was definitely a main line terminus, but a narrow thirty two foot long space would have been unusual as the only place to built a layout. Certainly, after the war, they both went on to build "conventional" O gauge garden layouts either with a couple of termini or a single station in a shed and a long run round the garden. Even in its last outing to the MRC show,the "traverser" had been replaced by a return loop. This was also one of CJF's suggestions for operating Minories- given that with an intensive sequence of suburban trains it doesn't really matter if what goes out soon becomes what comes in since one such train is very much like any other (And yes I do know that for their afficianados there are differences!)  

Edited December 1, 2020 by Pacific231G

[Flying Pig]

3 hours ago, Satan's Goldfish said:

Not the most artistic doodling, but how's about changing which tracks the platforms are between

 

The divergence angle of the Tillig slip makes @simon b's arrangement much more natural.  On the other hand, a replacing the tandem 3-way with a curved point would possibly absorb the extra 3° of the Tillig unit to give a better alignment of the approach tracks.  The loco siding could then easily be accommodated facing the station, which is perhaps more common on the prototype than the Minories orientation.  I have drawn it facing the departure line, but it could probably also be worked in trailing the arrival road (I would use a straight point to avoid the inner radius of a curved point on the running line).  Arrowed points curved on my sketch, L is the loco siding (obviously!).

 

 

There's potential to use the upper platform for long trains and shorten the lower one to permit additional platforms and docks to be fanned out as @BurscoughCurves did at Halifax Powell Street.

[simon b]

1 hour ago, Flying Pig said:

 

The divergence angle of the Tillig slip makes @simon b's arrangement much more natural.  On the other hand, a replacing the tandem 3-way with a curved point would possibly absorb the extra 3° of the Tillig unit to give a better alignment of the approach tracks.  The loco siding could then easily be accommodated facing the station, which is perhaps more common on the prototype than the Minories orientation.  I have drawn it facing the departure line, but it could probably also be worked in trailing the arrival road (I would use a straight point to avoid the inner radius of a curved point on the running line).  Arrowed points curved on my sketch, L is the loco siding (obviously!).

 

 

There's potential to use the upper platform for long trains and shorten the lower one to permit additional platforms and docks to be fanned out as @BurscoughCurves did at Halifax Powell Street.

 

That's the only issue with using the Tillig slip, it looks great but does mess up the track geometry. I did try it with a pair of curved points but the track centers are still very far apart, so I plan to make it look intentional by using the island platform one side and a bridge girder the other. I agree the loco siding is better placed on the down line if you have the room.

 

I'm now looking at enlarging that plan into something loosely based on Holborn viaduct. I have 3 long passenger platforms, with the short Island used for parcels only. What would have been platform 6 (where the class 15 sits) is just a loco spur.

 

[Compound2632]

What's missing there is the possibility of simultaneous arrivals and departures involving anything other than the upper platform line and one other. If the lower lines are given an independent connection into the departure line, clear of the double crossover, there's a lot more flexibility. This is the equivalent of the "third line" in classic Minories; it all serves to enhance the atmosphere of business in a confined space. But I agree that the problem that classic Minories seeks to address - reverse curves - disappears if the approach crossovers are on a curve. I think I've posted about the "New Victoria Line" earlier in this topic.

[Flying Pig]

1 hour ago, Compound2632 said:

What's missing there is the possibility of simultaneous arrivals and departures involving anything other than the upper platform line and one other. If the lower lines are given an independent connection into the departure line, clear of the double crossover, there's a lot more flexibility

 

True, but the layout does represent Holborn Viaduct pretty closely if you reduce platform 6 (top of diagram) to a siding.