Critique my San Francisco terminus plan in N scale

[2TallTyler]

Hello all!

 

I'm an American modeler planning an American prototype layout, but I based its operating scheme on British model railway philosophy more than anything I've seen over here: a heavily-trafficked passenger-only urban terminal with no mainline run. So I'm coming to you for advice and critique.

 

Here's the track plan:

 

Larger:

https://i.imgur.com/K4Wf7ED.png

 

The prototype is the Southern Pacific's Third & Townsend Depot in San Francisco, in 1973. By this point long-distance passenger trains were gone but the railroad still ran frequent commuter trains, diesels pulling coaches. Push-pull operation was still a few years away and two switch crews moved all the coaches between arrival and departure while the engines went to a wye to be turned around before returning to a compact engine facility near the throat. The station was, and its successor still is, crammed into city blocks and with a little compression, seems perfect to model.

 

Here are photos of the approximate era I plan to model:

http://wx4.org/to/foam/sp/san_fran/3rd/townsend4.html

http://www.snowcrest.net/photobob/3rdst1.html

 

 

The station has been replaced with a newer building with shorter platforms, and trains run push-pull with no switching at the station, but the track plan is still basically intact:

https://www.google.com/maps/@37.7736611,-122.3984107,729m/data=!3m1!1e3

 

I originally considered a fiddleyard, but since I'll be running a homogenous fleet which gets turned and reused repeatedly, often just a few minutes apart at rush hour, I'm considering building a loop so I don't have to worry about turning trains by hand. In N scale using Unitrack, it's no more space than I'd need for a train-length turntable or even space to turn a cassette by hand. The inner loop represents the wye where locomotives were turned and lets me turn locomotives even if there's a train sitting on the mainline track waiting for its next arrival. All curves are Unitrack R282 and R315, which are used on T-Trak modules that fit full-length passenger cars reliably.

 

The layout can accommodate up to three operators:

1. Station switcher
2. Mainline operator & hostler (runs all trains besides the switcher)
3. Tower operator (all switches off the main are powered and inside an interlocking; engines headed from the wye to engine servicing must reverse in a platform track)

The layout will be built on hollow-core doors and sit on folding tables. It's somewhat portable but I work weekends so it'll be a home layout. Operators will sit on both sides to avoid getting in each others' way, so it won't have a skyboard, just a low wall around the staging loops.

 

Thoughts?

 

[DCB]

I would do everything possible to increase the clear length of the mainline loop vis a vis the Wye loop.  You may be able to get 2 trains nose to tail in the loop if you optimise everything.  

You could add a separate turntable in the hidden area as well see pics.  Edit Pic now uploaded.

 

The  layout plan seems to be arranged for left hand running as per the UK, to my mind most US railroads ran right hand road so it won't work too well if you run right hand

Edited January 5, 2019 by DavidCBroad

[roundhouse]

I remember seeing a HO scale model of this station back in 2011 when we visited various home layouts at the Sacremento convention in 2011. Very nicely modelled but wasn't a complete layout. A

very different terminal today and coincidentally we will be in San Francisco tomorrow not far from there for lunch before heading home across the pond. Look forward to seeing this layout progress.

[2TallTyler]

Thanks for your input!

 

Here's a revised loop which will fit two trains end to end. The spur could be converted to a cassette dock, but for now I'll probably use it as a fiddle track for unusual moves -- maintenance-of-way equipment or a tank car of fuel for the engine servicing depot.

 

I am designing for right-hand running, and all trains depart from the platform tracks which have access to both main tracks. Is your concern the use of the main line while switching the wash tracks? American practice is much less worried about facing point switches on the main line, and our block signals make switching against traffic a non-issue, but I would like to keep switching uninterrupted while trains are arriving.

 

This revised plan adds the coach yard lead used by the real station but omitted from my original plan. Take a look at Google Satellite View. The geometry doesn't seem to work to tie it back into the main, so I'd put a permanently red signal right before the track goes out of sight looking like it'll connect. Those highway bridges are conveniently placed to hide the disappearing track and extra switches, although it'll obscure some visibility. The headshunt should be long enough for an entire train plus a switcher, but not enough to pull an entire track. I'm not into switching puzzles but this doesn't seem like an unreasonable restriction.

 

 

[The Stationmaster]

The only potential problem I can see is the amount of storage space on the return loops.  I'm not sure how their length relates to train length but I wonder if lack of room might constrain your operation - even with US level of train frequency? 

[2TallTyler]

My train length is a diesel locomotive (a short SD9 or GP9) plus three passenger cars. This is the length of each platform track, and the loop can fit two end-to-end. That said, they will not spend long in the layover loop before returning as the next arrival, just a few minutes at rush hour. I will have to rebalance rush hour in order to avoid running out of equipment — adding morning departures to get trains back into the loop ready to arrive, and adding evening arrivals to provide stock to turn and send commuters home in.

 

Speaking of train makeup:

 

In 1979 the SP ran both bilevel gallery cars and older single-level “Suburban” coaches. Apparently the bilevel consists often included a Suburban on the south end of the train for smoking; it wasn’t allowed in the new cars. Since I’m looping my trains I won’t be able to keep this on the south end, so it’ll probably stay next to the locomotive. This adds some switching to trains set up this way. I’ll experiment with this to see if it will add interest or just be a hassle.

[mdvle]

Another wonderful quirky prototype, and hence another rabbit hole to go down and waste time on pleasantly...

 

Certainly doable for at least some people to scale (the original station works out to about 40' in HO), and a bit of compression makes it perhaps a bit more feasible and the idea of a city street going through the middle of the station causing operational issues is the icing on the cake.

 

Even in your condensed version offers lots of opportunities and hours of enjoyment.

[mdvle]

The real thing track layout in 1956

 

http://wx4.org/to/foam/sp/san_fran/mission/1map.html

[mdvle]

For anyone interested, some useful sources of info.

 

First, while procudure was to turn the engines there was at least one period where they didn't and instead were willing to run the GP9's backwards as they apparently were cab equipped to make it more practical.

 

http://wx4.org/to/foam/sp/peninsula/trip/trip.html

 

That site is in general quite useful, with photos and timetables

 

http://wx4.org/to/foam/sp/a_sp.html

 

And Wikipedia has an informative page listing the equipment used if one wants to try and be accurate

 

https://en.wikipedia.org/wiki/Peninsula_Commute

[2TallTyler]

Thank you, mdvle, for those additional resources. Those will be very helpful.

 

I had a brainwave yesterday regarding the staging tracks. I'm an apartment-dweller with no power tools beyond a drill, and plan to build this layout atop hollow-core doors and set it atop folding tables. I have enough space to work on the layout shoved into a corner, but for ops sessions I'd have to pull it out to allow operators access to both sides. I worry about reliably connecting two baseboards while still being able to disconnect them for movement. But I realized that if I widen the baseboard a bit to a full 36x80" door, I could drop the loop below the station and keep everything on one board.

 

 

Lowering the bottom loop (or more accurately, raising everything else) to 3" should give me a manageable grade between the curve at left and where the tracks pass under the station. I will be working in foamcore and hot glue based on Prof Klyzlr's suggestions here and elsewhere, and my own successes building with the material. I'll keep the sides open for access to the hidden track and would probably need an access hatch in the middle somewhere in case something derails in the middle of the loop.

 

One key visual characteristic of this station is its alignment to San Francisco's street grid. Previous iterations were aligned with rectangular baseboard to emphasize this, but in this one I plan to model several streets to get that effect back.

 

Finally, there's a lot of empty space to the south of the station. The real station had the railroad's freighthouses here, which were disused and possibly torn down in 1979, plus some highway offramps. This leaves space for some light industrial switching. Maybe the SP leased out part of their freighthouse building to another company after their L.C.L business dried up. Any track arrangement or industry suggestions? Here's one option which uses a long lead to switch two spurs, and also adds a spur to the opposite side, mimicking a real-life running track which you can still see scars of in Google Maps satellite view at Townsend and 4th.

 

[mdvle]

The freight houses were replaced with the highway, so if the highway offramps are in place the freight houses are gone - at least in the real world, you can of course modify history and the placement of things to better suit your layout goals.

[mdvle]

Only you know your abilities for doing the structure of the base of the layout but I would point out that the connection can be reliable - just take a look online at all the free-mo and various other modular layouts that get setup and taken down on a regular basis.

 

As for your latest plan, I am not familiar enough with N to know if what you propose is practical or not, but a quick play with a ruler indicates a 3" gap would be insufficient for me to get my hands in to deal with any derailment or other issues that occur on the hidden portion of the layout.

 

Also note that a 3" gap also doesn't allow for track or a structure to support the upper level, so I suspect you are actually looking at more than a 3" difference in height, at which point your grade on the curve may become too much.

 

Anyone more familiar with N and it's physical realities that can comment?

 

Oh, and a side note, you may find responses slow for the next week and a half as Hornby (later today) and Bachmann (next Monday?) make their annual UK product announcements and thus many devote their time to debating the merits of what was or wasn't announced.

[roundhouse]

I would agree that 3" is tight  to rerail / access N scale stock although cant comment on gradients as all my N scale layouts have been built on the level.

Edited January 7, 2019 by roundhouse

[2TallTyler]

Thank you for the comments about the lower level, and the notes on the highway.

 

I did some tests with a ruler and the track and foamcore I'll be using, and found 4" to be a comfortable vertical clearance. When the track is close to the edge of the baseboard, 3" should be sufficient. If I start the grade where the loop comes together and end at the far left edge of the layout where the hidden tracks pop out from under the freeway, I can climb to 4" with a grade of between 3% and 3.5%. Definitely reasonable for a diesel and three coaches! Where the hidden tracks pass under the station tracks and building, there's only 3" of clearance, but it's close enough to the edge of the layout that this shouldn't be an issue.

 

The highway which is there now is not the one which existed in 1979. The original was built between the freight sheds and Mission Bay, intended to be part of the Embarcadero Freeway but never connected north of 5th Street. It was damaged in the 1989 Loma Prieta earthquake and torn down, replaced with today's ramp to surface streets on a new alignment in place of the freight sheds. See this Historic Aerials image from 1980:

https://www.historicaerials.com/location/37.774751490776964/-122.39576339721678/1980/16

 

In that image, there were freight houses on either side of several tracks. I've cut that down to one building to save space, and ripped up the tracks to the left. I figure the SP leased out the building and what little traffic remains is served from the other end by a local that runs midday between rush hours (at least unless I eventually add night lighting, in which case it'll run in the wee hours of the morning). The building has truck loading docks on the opposite side from the tracks, but those will be obscured (as in parts of the aerial image) by the disused freeway, which will cover up the hidden tracks. The 195 degree turnback loop at left will be hidden under the highway interchange, which will also provide that gritty under-the-freeway scene so emblematic of this station's approach.

 

 

 

 

[Darius43]

Interesting layout concept. One thing that may need to be worked out is that the low level loop is a “reverse loop” and this will need some complex wiring and switching at the double cross-over at the entrance to the station.

 

Darius

[Harlequin]

Interesting layout concept. One thing that may need to be worked out is that the low level loop is a “reverse loop” and this will need some complex wiring and switching at the double cross-over at the entrance to the station.

 

Darius

If DCC is used the reversing loop would actually be very simple to wire up using an "Autoreverser" and it would be almost completely invisible in operation.

[Darius43]

If DCC is used the reversing loop would actually be very simple to wire up using an "Autoreverser" and it would be almost completely invisible in operation.

With a single point connection of the loop I can see it being simple with DCC but perhaps not so simple with the double cross-over. I would be interested to see the wiring diagram required as it would be helpful to me as well as perhaps for the OP.

 

Cheers

 

Darius

[Harlequin]

Here's one way to do it:

 

The green section of track would be isolated and fed from the Autoreverser only. Everything else would be connected in the conventional way.

 

The green, autoreversed section of track needs to be at least as long as the longest train you intend to run. (Plenty long enough in the diagram above!)

 

I've only shown two track feeds for clarity but obviously you'd use more for reliability.

Edited January 13, 2019 by Harlequin

[2TallTyler]

Thank you for the wiring diagram. Yes, I am using DCC. The longest train is an engine and three coaches, or a short freight train of the same length.

 

Is there any reason to make the auto reversing section longer than the train + wiggle room? The reversing section shown here has the potential to fit two trains at once. I was thinking about having just the balloon loop itself be the reversing section, with gapped joints where the two tracks come together.

[Harlequin]

Thank you for the wiring diagram. Yes, I am using DCC. The longest train is an engine and three coaches, or a short freight train of the same length.

 

Is there any reason to make the auto reversing section longer than the train + wiggle room? The reversing section shown here has the potential to fit two trains at once. I was thinking about having just the balloon loop itself be the reversing section, with gapped joints where the two tracks come together.

No real reason for the reversing section to be longer than a train plus some leeway but if you can safely make it longer then you won't be caught out in future if you want to run longer trains.

 

And I guess it's best to place the reversing section in a simple area of track to avoid potential problems where the rear of the train is passing over complex pointwork while the head is inside the section. (Or vice-versa.)

Edited January 16, 2019 by Harlequin