Serial Staging

A the second helix track could indeed be used for serial staging. This is where multiple trains are staged on the same track. They must emerge (and arrive) in a fixed sequence - you don't get random access to any train being staged. If you have 40' of track in the helix that should be enough to hold 3  moderately long HO trains.

However there's another approach to staging on a helix. In this method, sidings come off the helix at different levels and are used to hold the staged trains. The most complex example of this that I'm aware of is the monster N scale helix put together by Rich Weyand. Scroll to the bottom of this page for some photos.

Cheers,

Charlie

Charlie that "N" scale RR is

Charlie that "N" scale RR is HUGE and just how many people are building it?

Dan

Track Cleaning

OMG that thing will be a bear to keep clean..

An impressive feat of engineering. Maybe won't be an issue depending on how the room is filtered.

Chris

Staging within the helix...

I've started my helix, which will get trains high enough to allow for a walk-under for access between rooms.  It'll be 3 turns of 42" minimum radius. with 2 separate visible scenes.  The first of these will be at the start of the 2nd turn, and will depict Glen Frazer, CA, where my great-grandfather was section foreman.  The prototype had a freight house and a passing siding, and I'll have the start of the passing siding shown.  Both the main and the siding will disappear into the trees, but I'm reluctant to build the end of the siding in the hidden portion of the helix, so it'll actually occupy the entire 2nd and 3rd turns of the helix.  The end of the siding will be at the end of the 3rd turn, where the second scene, depicting the trestle crossing Alhambra Valley, will start.  Since the diameter of the helix is actually over 7 feet, this siding will be almost 50 feet long, with the hidden portion over 40 feet long.  It occurs to me that this provides a good place to stage a train, at least until we can get my wife's stuff out of the next room where the track will eventually go.  The area where the helix is being built is already dedicated, so I could use both the siding and main as staging tracks.

Now, since completing the helix will come later this year, I decided to build a 45" radius loop surrounding the 1st turn of the helix as my first project.  And in fact, that was the first track to actually have trains running on it!  After the helix is complete and the main line goes somewhere, it can serve as a staging track, too.  So I've accidently backed into having staging within the helix!

References

Mike, if you're thinking of a recent article, it might be Jim Vail's article in Model Railroad Planning 2008. He describes adding a second track outside the helix for more staging, among other helix ideas.

Don Mitchel has suggested a couple of times using a below-deck helix solely as staging, but that doesn't seem to be what you are looking for here.

John Armstrong suggested this often in a double-track helix with crossovers made from curved turnouts, although my one experience with this in real life at Otis McGee's Armstrong-designed layout shows it's a bit less satsifactory than other forms of staging.

One of the articles where Armstrong described this in some detail is in his plan for the Atlantic & White Mountains RR, which is found in Model Railroader, February 1991  and was also published in 20 Custom Designed Track Plans  (Kalmbach, 1994).

One of the challenges with this approach is that only half of the helix is available for staging (one must park the trains between the correct crossovers to allow other trains to pass through the helix.). The alternative is to dedicate one helix track to serial staging, which is what Jim Vail describes.

Weyand's N&W

One can read more about Rich Weyand's design in Model Railroad Planning 2002.

Mike, if you're thinking of a

Mike, if you're thinking of a recent article, it might be Jim Vail's article in Model Railroad Planning 2008. He describes adding a second track outside the helix for more staging, among other helix ideas.

Don Mitchel has suggested a couple of times using a below-deck helix solely as staging, but that doesn't seem to be what you are looking for here.

John Armstrong suggested this often in a double-track helix with crossovers made from curved turnouts, although my one experience with this in real life at Otis McGee's Armstrong-designed layout shows it's a bit less satsifactory than other forms of staging.

Thanks, Byron. I actually did run into that article independently after I wrote my original post.. What I had been looking for was an article that had something about staging on a helix in its title. I happen to start perusing MRP 2008 and found Vail's article even though no mention of staging was done in the title.

What we're trying to do is to find a way to add staging to a layout that already has all the mainline in place. Here's a diagram of the layout: http://cpcrr.org/Layout_files/CPCRR%20Layout.pdf  . The helix is on the left in the green marked Murphy Grade/Morgan Hill Siding. There are a couple of other places to add staging, but those would be in the form of passing sidings in trackage under the benchwork.

The one real drawback with the helix staging is not really the helix itself but the fact that the helix is in the middle of the modeled line (San Jose to Watsonville). OTOH, it's not without reason that at start of an opsession a train or trains would be "enroute" somewhere when the clock's turned on.

The layout's in a loft area with an ascending staircase to the lower right in the diagram and access is gained via a swinging gate in the layout. Staging above the staircase is not really feasible as it would impinge on the gate area. Essentially, all staging has to be added within the footprint already covered in benchwork. In this case, the easiest place to add (or more correctly, create) staging is in the helix. It's currently open and easily accessible and even when enclosed is in a location where it's relatively easy (allowing for 50 - 60 something auld pharts) to gain access. Of course, the ultimate fix (short of a complete tear down and re-design) would be to recruit some young whippersnappers who would have no problem bending down and crawling inside the helix if there were problems. Er, I mean WHEN there are problems.

I'm beginning to think that the whole purpose of a layout is to serve staging.  Let's face it. It is possible to have a layout without staging, but can you imagine staging without a layout? I sure can't.

With deepest apologies to Wm. Shakespeare:

The train's but a walking shadow, a poor player
That struts and frets its hour upon the layout
And then is heard no more: it is part of an operating session
Run by an idiot, full of sound and fury,
Signifying nothing.
 

Mike

Shall The Helix Be Unbroken By And By Lord, By and By?

A the second helix track could indeed be used for serial staging. This is where multiple trains are staged on the same track. They must emerge (and arrive) in a fixed sequence - you don't get random access to any train being staged. If you have 40' of track in the helix that should be enough to hold 3  moderately long HO trains.

As it's double track, we could actually have 6 moderate sized trains in the helix in a pure serial mode, 3 in each direction. However, we're looking for a bit more flexibility.

The idea we ultimately came up with is having 3 or 4 curved crossovers within the helix. Certainly not the best of ideas, but given that staging needs to be retrofitted, a feasible one. With alternating directions to the crossovers, we think we can stage 3 trains and still allow for something other than true serial staging. We'll see. If not, I will no doubt be verbally flogged for suggesting the idea in the first place. Either that, or I will be banished to inside the helix to fix any and all problems that arise as a direct result of my moronic suggestions being implemented.

Mike

Half better than blocked, in my view

Yeah, I thought Chuck might have too little staging for his operating vision when I first saw the layout last Spring.

As a general concept, I tend to prefer staging that allows any train to come and go without being in a strict order. You usually end up having to leave at least one empty slot anyway for that first arrival, in any case.

We do use somewhat serial staging in Jim Dias' current ops plan and at some point the owner has to go and move trains up a block or two in staging to make room for arrivals. Not ideal, because you always have to keep in mind where the empty slot(s) is/are. And if a train falls down on its schedule on the visible layout, it can cause problems for trains in staging that are theoretically miles and hours away, because the slots have to be filled in order.

There are a couple of other alternatives at Chuck's layout, I think, but they require a bit more radical reworking, for which he may not be ready now (if ever). It would take some re-ordering of towns, I think, but I don't remember the exact configuration of the shelves, so I could be way off.

Staging On A Helix - Model Railroader 10/97

Check the following article:

Union Terminal Ry. in HO Scale by Don Mitchel

A 4x8-foot track plan with staging on a helix

Model Railroader Magazine, October 1997

A great track plan but I eliminated the helix in favor of two staging yards in sliding drawers:

Did you try the staging on a helix?

Serial Staging

Serial staging should be considered as "a" solution, not as "the" solution.  It works in some cases depending not only on the physical space available but also on the operating philosophy.

One of its advantages is that it can be used to maximize length of trains in relation to available space.  It also reduces the number of turnouts needed to stage a given amount of trains.  One disadvantage, as pointed out in another post, is that it limits operational flexibility by requiring trains to exit in the same order they entered.

Using one track of helix with turnouts along the turns should not be considered serial staging.  It's more akin to parallel staging with a different physical layout than the usual "tines of a fork" staging.  Consideration of this type of helix construction should take into account the access (or lack thereof) for maintenance of the switch track and switch machines.

FWIW, I've been using serial staging on my home layout for the past 8 years.  It holds 6 trains in each direction and we have yet to run through them all during our usual 3 hour op sessions.  It works for me, but as per the opening paragraph, it's not for everybody.

Don Mitchell 

2 Armstrong plans

There are two plans in "20 Custom Designed Track Plans" by John Armstrong (Kalmbach, 1994). Western Colorado  and the Atlantic & White Mountains both used helix staging. The A&WM had a fairly extensive discussion of staging in a helix.

Tore Lydersen

One of the best examples of

One of the best examples of staging on a helix was on Otis McGee's SP Shasta Division.  He has a fairly large radius helix and tall, since inside the helix is the location of an agent's desk.  He uses double tracks in the helix with cross-overs on at least one side of each turn.  I didn't actually get into the helix so I can't say whether or not there were cross-overs on the opposite side of each turn as well, but I believe there were with the cross-overs in the opposite direction.  Given that his operating era is 1952, he is able to accommodate a fair length train on each turn with the ability to bring trains out-of-phase via the cross-overs.  The agent is able to set up tracks for trains leaving and entering available staging slots.  There's a photo of the inside of the helix here: http://www.pbase.com/atsf_arizona/image/130299413, courtesy of John Sing. 
John Moran
Bradenton, FL
 

from The Railroad Index

Did a search in the index for "staging helix", and these two popped out:

Union Terminal Ry. in HO scale; A 4x8 foot urban track plan with staging on a helix; Don Mitchell; Model Railroader Oct 1997 pg 90

The Silver Gate Northern; A helix can reach its full potential when combined with serial staging; Don Mitchell; Model Railroader Apr 1995 pg 96

Mid-run helix comments

I concur with any concerns about having a helix in the middle of a main line run. I installed a 5 turn double track helix to postpone running the main line completely around the basement (a no-lix). This connected levels and allowed earlier ops. Even though the helix was supposed to be "temporary" until the eventual no-lix expansion happened, it has now been operational for five years. So much for temporary!

I regret that the trains seem to take forever in the helix. This also causes an "operator clog" near the helix while we wait for trains to emerge. I can't wait to expand and run the main around the outside walls thus eliminating the need for the helix! Like many building their "dream" layout, time and resources sober us to the fact that maybe we are attempting too much.

Obviously, my recommendation is to avoid any helix in the middle of a linear run. Using one at the end of the run to access staging or a continuous loop is less of a problem. Adapting/modifying the helix to accomplish staging in whatever form is to be desired, but not at the expense of having it in the wrong place to start with.

Earl Paine, Skippack, PA