Minories with reversing loop/continuous run

[melmoth]

On 26/05/2020 at 14:10, Chris116 said:

You could reduce the climb on the branch if you made the mainline go down from the junction and then climb back through the fiddle yard. I know that makes the woodwork more difficult but I think one or two CJ Freezer plans used the idea.

 

Or start the incline from the end of the fiddle yard as far as the junction, then bring the main line back level before re-entering the fiddle yard. Gives a longer climb to the terminus and avoids slopes in the fiddle yard and/or difficult woodwork.

[Zomboid]

Would a kettle plus 7-8 carriages be happy climbing a 4th radius incline?

[melmoth]

Don't know. The length of run on the 4th radius would be about 15", followed by a transition curve of about a foot to the junction, where the pointwork would be on the level. The gradient doesn't have to be the 1:50 specified for the branch because any height gained prior to the junction is a bonus. If the climb starts just before curve starts, you'd have about 30 inches run. Even if the line only rises 1/4 inch (1:120) in that, it helps offset the main climb, or allows an extra 1/4 inch clearance under the terminus.

[TomJ]

3 hours ago, Zomboid said:

Would a kettle plus 7-8 carriages be happy climbing a 4th radius incline?

 

Not sure if my woodwork is up to this anyway!!

 

Thanks for the suggestions though - something I'll look into

[Chris116]

1 minute ago, TomJ said:

 

Not sure if my woodwork is up to this anyway!!

 

Thanks for the suggestions though - something I'll look into

Measure twice and cut once! Take things slowly, checking everything as you go and you will soon find that woodwork is not so hard as you currently think. 

When you buy the wood make sure that it is good straight pieces and not some of the twisted rubbish that a certain DIY organisation try to pass off as straight.

[TomJ]

I struggle with getting a straight cut!! Which is ironic as my day job is as an anaesthetist. So happy manipulating tiny needles into small spaces under ultrasound guidance with a very steady hand. But give me a saw and a piece of wood and it goes all over the place.

[DCB]

The key to making this sort of layout work is keeping the gradient within reason.  The places one track crosses another at different levels is the pinch point, so making the vertical difference as small as possible while still letting full size trains through is crucial.  Now in OO i will happily solder rail to pcb board sheets so the whole thing is less than 10mm thick, of use 6mm MDF with flexi track for about 12mm thickness.  Other people put 50mm framing under it plus the 60mm clearance almost doubling the gradient.   In N you can't really put a station over a fiddleyard on a small layout as you can't get your hands in and small children under 4 who can get bored after two days of an exhibition..   Hence exhibit a...Hand scrawled alterations on @Melmoth 's beautiful plan.    Minimum clearance where tracks above other tracks, station platforms brace baseboard over return loop Not quite Minories, trains can arrive or depart any platform and depart either bottom or middle as one arrives at top.   Lower sidings are carriage sidings, add goods sidings and loco spurs to taste.  Trains arrive top platform and run round and propel coaches to carriage sidings.  for departures loco positions coaches in suitable platform bottom or middle some time before departures

[CKPR]

Nigel McMillan's " Eastwood Central" as featured  as Railway of the Month in the March 1971 RM had a track plan that involved a suburban terminus alongside through running lines  and high and low level loops

[melmoth]

3 hours ago, DavidCBroad said:

The key to making this sort of layout work is keeping the gradient within reason.  The places one track crosses another at different levels is the pinch point, so making the vertical difference as small as possible while still letting full size trains through is crucial. 

 

Hi @DavidCBroad . A really good point there.

 

A couple of general responses to your whole post:

 

1. The original  Minories was obviously designed for complete flexibility regarding arrivals and departures, which might not be needed with an out-and-back plan such as this

 

2. Bringing the terminus inside the fiddle yard will mean a tighter radius at some stage of the climb to the terminus, and that can't necessarily be lessened because of the need to cross the return loop, regardless of the point at which the branch needs to cross the continuous run.

 

I'm going to sketch a few things out and see what works.

 

[melmoth]

Most of this should make sense.

 

1. Return loop is now double track. Blue circle indicates single slip on return loop to allow anticlockwise trains to access fiddle yard loop and hidden sidings

2. At X, branch is 2" above main line, at Y branch is 2 3/4" above main

3. Main rises from left hand tunnel at 1:120 (approx) to junction, then at between 1:55 and 1:60 to summit at Y. Main falls at a fairly minimal grade to the junction with the return loop. Double junction provided here instead of crossover.

4. Yellow area indicates footprint of the upper level. This is only an approximation and can be altered to suit terminus track plan. The terminus could be placed in the top left hand corner for example.

5. A fair amount of the 'hidden' trackwork can now be made accessible without limitations on clearance.

6. Although the visible outer curves are nominally 4th radius, transition curves are used where possible, so this isn't a precise value at any given point on a curve.

7. I would be tempted to put a short tunnel on the branch to disguise what is otherwise a 180 degree turn. Also possibly have more of the return loop open to view in a cutting.

 

I think that covers most of the improvements suggested by @Zomboid and @DavidCBroad .

[Chimer]

It's turned itself into two layouts with a double-sided backscene roughly following the top edge of the yellow area.  Rural to the "north" with sweeping (mostly) curves, gradients and junctions, and inner city to the south, with the terminus approached by a viaduct (X-Y) over a busy yard of some sort surrounded by other lines going every which way.  Brilliant …..

[Windhawk]

Hi,

 

Have you considered not having the layout on two levels, but having it all on the flat to have easier carpentry? On one side have a double track loop and on the other the return loop, leading a line off of the reverse loop to the through platforms of the station? Kind of folding the terminus to reversing loop on itself. I've drawn a sketch in SCARM that hopefully displays the image more clearly. The area over the reverse loop could be a good space for a town scene that could lift off for access to the loop.

 

Zac

Edited June 4, 2020 by Windhawk
Added an image and expanded text

[Keith Addenbrooke]

On 04/06/2020 at 09:46, Windhawk said:

Hi,

 

Have you considered not having the layout on two levels, but having it all on the flat to have easier carpentry? On one side have a double track loop and on the other the return loop, leading a line off of the reverse loop to the through platforms of the station? Kind of folding the terminus to reversing loop on itself. I've drawn a sketch in SCARM that hopefully displays the image more clearly. The area over the reverse loop could be a good space for a town scene that could lift off for access to the loop.

 

Zac

That’s neat.  Although the reversing loop line passes very close to the end of the Station platforms I’ve seen plans that basically hide this line inside the Station building - if the end of the platform roads is under a covered roof then it can work very well.
 

For a prototype, Moor St in Birmingham could be a reference point - the lines in front of the station head into Snow Hill Tunnel, under the city centre exactly as you suggest.  I realise I’m not the customer for this one, but if I was still in N Gauge you’d have a sale.