Helix Query

[john new]

46 minutes ago, Newmodeller96 said:

I’m not sure where the double slip in the fiddle yard you are mention is? 

Where the two halves are joined. It can’t be a diamond crossing (that would be of no use) so must be a slip to allow ingress/egress to the various sidings.  Cruel screen grab below. EDIT After posting the image I have also noticed that as drawn the fiddle yard entry crossover has to have a single slip to work - better replaced by a crossover and left hand point for the same future maintenance issue. It would need the crossover moving one point length to the left (curved?).

 

 

 

Edited January 20, 2023 by john new
Text accidentally split by the image and extra note.

[Newmodeller96]

7 minutes ago, john new said:

Where the two halves are joined. It can’t be a diamond crossing (that would be of no use) so must be a slip to allow ingress/egress to the various sidings.  Cruel screen grab below. EDIT After posting the image I have also noticed that as drawn the fiddle yard entry crossover has to have a single slip to work - better replaced by a crossover and left hand point for the same future maintenance issue. It would need the crossover moving one point length to the left.

 

 

 

Ah ok I see what you mean now. This is actually the main station and has already been laid as per the plan. 

[john new]

23 minutes ago, Newmodeller96 said:

Ah ok I see what you mean now. This is actually the main station and has already been laid as per the plan. 

I would suggest you make a sketch and move paper blobs around on it to make sure your stock can run where you want it to go. I am maybe not reading the plan correctly but as drawn it appears to show that of all that ladder of sidings you can only reverse a train from the inner circle over two diamond crossings into the back two right hand sidings and also get into the front left. The other three left hand sidings form an inglenook style separate system going over the diamond into one long right hand side road but unconnected to the rest of the layout.  No access whatsoever to those sidings from the other main circle due to use of a diamond not a single slip.
 

Hoping I am misreading the plan.

 

Edited January 20, 2023 by john new

[Michael Hodgson]

1 hour ago, RobinofLoxley said:

Also, it cant be ruled out, but on the basis of what Harlequin has drawn, the descent might be enough by itself to get sufficient separation. The fiddle yard junction can also move back to the opposite long side, creating even further distance for descent.

As I understand it, that's a lift out out section for access to the room.  putting any track on a second level of that board adds to construction difficulty, though possible.

[Newmodeller96]

@Michael Hodgsonspot on. Where the points are on that plan would be fine as I can use what’s left as a removable section! 

[Harlequin]

11 minutes ago, Newmodeller96 said:

@Michael Hodgsonspot on. Where the points are on that plan would be fine as I can use what’s left as a removable section! 

Relatively easy to put the turnouts on the removable section if you want - just a bit more wiring if they have point motors and one more track joint.

 

[Newmodeller96]

54 minutes ago, Harlequin said:

Relatively easy to put the turnouts on the removable section if you want - just a bit more wiring if they have point motors and one more track joint.

 

@Harlequini think it should be fine. I’m going to have a bit of a play with the area of the TMD at the bottom of the design and include run to the helix into it a bit more. 
 

[Newmodeller96]

2 hours ago, john new said:

I would suggest you make a sketch and move paper blobs around on it to make sure your stock can run where you want it to go. I am maybe not reading the plan correctly but as drawn it appears to show that of all that ladder of sidings you can only reverse a train from the inner circle over two diamond crossings into the back two right hand sidings and also get into the front left. The other three left hand sidings form an inglenook style separate system going over the diamond into one long right hand side road but unconnected to the rest of the layout.  No access whatsoever to those sidings from the other main circle due to use of a diamond not a single slip.
 

Hoping I am misreading the plan.

 

John thanks for this. I totally understand what you mean. 
I have done some drawings to hopefully help. The idea is that the top left sidings are a small EMU sidings for the branch line / slow services coming into the station from “London” (off layout). The top 3 platforms 3,4&5 are fed from these and are the lines running slow/stopping services to London. 
 

platforms 1&2 are the mainline UP/DOWN services to London / the South coast, these trains would be stored at loco depots nearer their destinations or the larger depots on the network. Ideally there would be 2 more lines coming out of the station which would be slow UP/Down lines but I didn’t have space for this as I wanted some scenic space too.

the diamonds you mention are all double slips so have the ability to open the upper platforms to main loops. 

with the help on this forum I am now going to rework the lower part of the layout to make it a bit more interesting - he says fingers crossed. I was never overly pleased with this area of the design hence why I started with the station area first. 
 

hope this helps

 

h

 

[DCB]

2 hours ago, Newmodeller96 said:

John thanks for this. I totally understand what you mean. 
I have done some drawings to hopefully help. The idea is that the top left sidings are a small EMU sidings for the branch line / slow services coming into the station from “London” (off layout). The top 3 platforms 3,4&5 are fed from these and are the lines running slow/stopping services to London. 
 

platforms 1&2 are the mainline UP/DOWN services to London / the South coast, these trains would be stored at loco depots nearer their destinations or the larger depots on the network. Ideally there would be 2 more lines coming out of the station which would be slow UP/Down lines but I didn’t have space for this as I wanted some scenic space too.

the diamonds you mention are all double slips so have the ability to open the upper platforms to main loops. 

with the help on this forum I am now going to rework the lower part of the layout to make it a bit more interesting - he says fingers crossed. I was never overly pleased with this area of the design hence why I started with the station area first. 
 

hope this helps

 

h

 

 

I had no internet for several days and my father in law died Monday so I missed this thread.  The only problem, and its a huge one.  with this plan is that there is nowhere for trains to run to.  either the cess to the spiral is the wrong way round or the station is.  Either way it won't work as drawn.   See my doodle, though I wouldn't recommend building it as the space could be used an awful lot better,

Edited January 20, 2023 by DCB

[Newmodeller96]

17 minutes ago, DCB said:

 

I had no internet for several days and my father in law died Monday so I missed this thread.  The only problem, and its a huge one.  with this plan is that there is nowhere for trains to run to.  either the cess to the spiral is the wrong way round or the station is.  Either way it won't work as drawn.   See my doodle, though I wouldn't recommend building it as the space could be used an awful lot better,

Hi, thanks for your reply, and very sorry to hear about your father. However I have already built the station area so that is fixed in stone. It is based on Orpington so I know how I want it to feel. 

[DCB]

4 hours ago, Newmodeller96 said:

Hi, thanks for your reply, and very sorry to hear about your father. However I have already built the station area so that is fixed in stone. It is based on Orpington so I know how I want it to feel. 

If  # Harlequin's first suggestion does not work for you I would suggest you abandon the helix and build a fiddle yard on the top level opposite the station. To operate your last plan you will have to reverse trains up and down the spiral which might work well for Emus and  DMUs  but wont end well with loco hauled trains,  I have a steep grade on a 2ft ish radius to low level dead end sidings  for the main line masquerading as  a connection to the branch which I always reverse spare main line  trains down and there is no way  I can reverse them back up with out tension lock couplers over riding and causing stock and bogies to lift and derail.

[Harlequin]

8 hours ago, DCB said:

 

I had no internet for several days and my father in law died Monday so I missed this thread.  The only problem, and its a huge one.  with this plan is that there is nowhere for trains to run to.  either the cess to the spiral is the wrong way round or the station is.  Either way it won't work as drawn.   See my doodle, though I wouldn't recommend building it as the space could be used an awful lot better,

 

 

 

I don’t think there’s a problem. It just needs a station at “New design here” where trains from the FY can terminate and reverse. That could be as simple as two platforms either side of the main lines and a trailing crossover. Something a bit more developed would be more interesting.

[Newmodeller96]

2 hours ago, Harlequin said:

 

 

I don’t think there’s a problem. It just needs a station at “New design here” where trains from the FY can terminate and reverse. That could be as simple as two platforms either side of the main lines and a trailing crossover. Something a bit more developed would be more interesting.

I think this is what I am thinking off. I originally had a smaller 2 platform station with a small yard off to the side for maintenance trains in my head a little like what is around the Hither Green area of the mainline. I have put a picture of Hither Green below do you think a smaller version of this could work with the addition of the maintenance yard! Ignoring the diverging red line! 

[Chimer]

It would help with the big picture to know what you're thinking of doing at the bottom of the helix.  Just a series of dead-end sidings, or storage loops with a balloon reversing loop at the far end?  Or what?  Either way, with just one helix, whether single or double track, trains are going to go down from one circuit (the outer clockwise circuit as per your latest drawing) and come back and shift to the other one going the other way round.  There is then no way back to the storage sidings without reversing in the visible section, which is an interesting manoeuvre (described by Harlequin above) for loco-hauled passenger trains, and next to impossible for freights with a brake van.  And as DCB points out, it works better if a train leaving your terminus can get to the storage sidings without a visible reverse, which isn't possible as presently drawn.  As it's a given that the terminus isn't changing, moving the helix to the bottom right corner, with the junction leading to it situated somewhere top-leftish, would perhaps be better (though I can see the temptation to keep part of the helix in that bottom left recess).

 

If there was some way of making the "to be developed" station a junction, such that a train from the terminus could branch off there to get to the helix, this could be operationally very interesting.  I can't see any way to make that work, starting from your current "givens".  But I'll keep watching and thinking .....

Edited January 21, 2023 by Chimer

[DCB]

A  "Developed" station where you can  reverse trains would sort things operationally.  See doodle.   PW yard lower left

I would definitely have double track leading to the helix so trains can pass and you can run a down train off the helix line as an Up train runs towards it.

[Harlequin]

On 20/01/2023 at 11:30, Newmodeller96 said:

@RobinofLoxley sorry I should have said. I am in 00 so was hoping to use a single 3rd radius helix. I will be modelling late NSE to modern southeastern stock so mainly EMUs and DMUs which is why I hadn’t added a return loop into my equations. Hope this helps. H

 

[Chimer]

Just now, Harlequin said:

 (Quoting OP): I will be modelling late NSE to modern southeastern stock so mainly EMUs and DMUs which is why I hadn’t added a return loop into my equations. 

 

Missed that, sorry ...

[Michael Hodgson]

14 hours ago, DCB said:

 there is no way  I can reverse them back up with out tension lock couplers over riding and causing stock and bogies to lift and derail.

 

A very valid point. 

Even with EMUs/DMUs if your stock consists of a power car at one end only and tension locks within the set, propelling is asking for trouble.

It may be OK with bar couplings, and I'd be interested to see it with Hunt couplings or similar.

[Newmodeller96]

9 hours ago, DCB said:

A  "Developed" station where you can  reverse trains would sort things operationally.  See doodle.   PW yard lower left

I would definitely have double track leading to the helix so trains can pass and you can run a down train off the helix line as an Up train runs towards it.

@DCB I like the idea of this but worry how much it covers the helix so I couldn’t do any maintenance if needed. 

[DCB]

Going back a bit, Frank Dyer of Borchester used kick back fiddle yards where trains ran into a head shunt and then reversed into dead end sidings.    maybe a headshunt or kick back could be added across the lift out hidden behind scenery.   Longer the better.  That way MU trains can come up the spiral power unit leading and reverse back down.   Then tricky cheat, loco hauled trains for clockwise come up with pilot engine on the front and the train loco comes up behind, the pilot uncouples  and the train loco takes the train on.  It keeps the illusion that trains go somewhere and still lets you run trains round and round. Backing down shouldn't be too difficult especially if the FY sidings and especially the point work slope down slightly

 

Edited January 22, 2023 by DCB

[Newmodeller96]

5 hours ago, DCB said:

Going back a bit, Frank Dyer of Borchester used kick back fiddle yards where trains ran into a head shunt and then reversed into dead end sidings.    maybe a headshunt or kick back could be added across the lift out hidden behind scenery.   Longer the better.  That way MU trains can come up the spiral power unit leading and reverse back down.   Then tricky cheat, loco hauled trains for clockwise come up with pilot engine on the front and the train loco comes up behind, the pilot uncouples  and the train loco takes the train on.  It keeps the illusion that trains go somewhere and still lets you run trains round and round. Backing down shouldn't be too difficult especially if the FY sidings and especially the point work slope down slightly

 

@DCBthis does solve all the issues with getting down line trains back onto the layout from the FY. Not sure if I would have the space for that points layout but we shall see. 

[Harlequin]

Before committing to any major redesign on the basis that multiple units running with the driven end at the rear is a problem I suggest that you need to establish that fact with the kind of rolling stock you'll be running.

 

Obviously in the real world MUs don't need to turn and so you'd sort of expect Hornby, Bachmann, et al to make their model MUs work reliably in the same way. But I accept that there might be issues.

 

It would be interesting to hear from someone with real experience of this.

 

Edited January 22, 2023 by Harlequin

[Newmodeller96]

2 hours ago, Harlequin said:

Before committing to any major redesign on the basis that multiple units running with the driven end at the rear is a problem I suggest that you need to establish that fact with the kind of rolling stock you'll be running.

 

Obviously in the real world MUs don't need to turn and so you'd sort of expect Hornby, Bachmann, et al to make their model MUs work reliably in the same way. But I accept that there might be issues.

 

It would be interesting to hear from someone with real experience of this.

 

I have very little running stock at the moment so I will be building by stock around what works for the layout to an extent. 

[Chimer]

I've just twigged that we were here about a year ago, with the main differences being that the terminus now exists and a helix has come into the equation - one of the issues then and now is getting trains that leave the terminus home again.  How about a double junction on the left-hand side, branching tracks falling inside the main circuit at the top edge of the bottom baseboard to a balloon loop in the bottom right-hand corner?  You could take dead-end storage sidings off the loop if really necessary, but you've got a lot of MU siding space already - how much do you need?

 

Any train starting from low-level storage sidings would still need to reverse to get back there, so if these were your main line fast trains you would have to bring them into the terminus platforms, or stop in the through platform 2 and reverse from there .....

 

I've used 22.5" (R4) and 24.5" radius on the "big bends" to maintain 2" (Streamline) spacing as you're using Streamline points.  The gradients are steep, but I guess OK for MUs.

 

 

[Newmodeller96]

I have done some work today on the design. Thanks to @DCB for the idea of getting a larger branch station on the opposite side of the layout.

 

I’m hoping to add the headshunt idea next to points for the helix but just need to work the best way to do it.