Model Train Journal

All:

Awhile ago, a friend visited the layout with his 3rd Rail NYC Hudson. It was not a pretty operating session. While my Williams Pennsy engines were very forgiving, the 3rd Rail locomotive found every low or uneven spot on the layout. In addition, the declining elevation coupled with curves were a problem. The original concept behind the idea of elevations was to run helper engines (snapper is the Pennsy term) for trains, but the layout is really too short to realistically support that notion.

The root cause of these problems is pretty straightforward and self-inflicted: I used plywood (11/32) for the subroadbed that was too thin. The thinking was to save weight, but the thin subroadbed requires a lot of bracing - which is what I am now correcting.

The result of the operating session was a list (longer than I would like) of trackwork areas that need help. So I set out to fix them and this is some of my progress.

In the photo, the red arrows indicate the areas that have gotten an increase in height. The track still descends somewhat, but the grade is much more gradual. The track and Vinylbed in the middle of the photo will be re-aligned slightly.

Once that is done, the bridge at the rear of the photo (from the Hi-tension tower to the left edge of the photo) will be replaced. That will involve rewiring a double-crossover.



George

George,

So it was a good idea to let that "alien" loco run on the Panhandle.It helped find some non-conforming points.

I wonder how many others have this kind of problem when they let others run their locos or even a new loco on their layout.

rogruth wrote:George,

So it was a good idea to let that "alien" loco run on the Panhandle.It helped find some non-conforming points.

I wonder how many others have this kind of problem when they let others run their locos or even a new loco on their layout.

Roger,

Yeah, my friend kids me about allowing "foreign" power onto the Panhandle. But it really is a good idea to test your layout with engines that have close clearances. Which is why I wanted to do it and keep doing it. My Williams engines - K4s, L1s, B6sb - all run just beautifully. They take whatever lumps and bumps are out there and perform. My Lionel M1a has a scale pilot that occasionally hits the center rail in this very area I worked on last night.

I don't know how many others have this kind of problem, but I think doing it is a good idea. You know your own engines and you can drive them gingerly in the problem spots and unconsciously avoid the issues.

It feels good to put some of these issues to bed.

George

G3750,

Just rename your railroad the Maumee & Western Railroad and your dips will be authentic.
Reference: http://youtu.be/7IcMnlBtH4c
The first minute is scary.

Seriously, thank you for the post. You might have saved someone (me for one) from having the same problem. I have been considering 1/4" (0.25) plywood (O three rail layout) for the same reason, light weight. Eleven thirty seconds is 0.344" and was not strong enough. Maybe I will rethink and use 1/2".

Wayne, nothing wrong with thin ply, its the way you use it. May I suggest you run a central spine box section, doesnt have to be completely boxed in you can leave enough gaps to insert wires into thus making it a useful conduit.

I built boats from 1/4" luan and these lasted years. Their lightness was useful since it was middle school kids making them, the box section central seat that ran from stem to stern was the thing that stiffened them up, along with 1/4" moldings as rub rails and internal ribs or side braces.

Its what I SHOULD have done with my baseboard but I was in such a hurry to run some trains that I made the usual ping pong table with 2x2 external framing and legs.

webenda wrote:G3750,

Seriously, thank you for the post. You might have saved someone (me for one) from having the same problem. I have been considering 1/4" (0.25) plywood (O three rail layout) for the same reason, light weight. Eleven thirty seconds is 0.344" and was not strong enough. Maybe I will rethink and use 1/2".

You're welcome. That was my intent.

I would strongly recommend the 1/2" or even 3/4" plywood (sanded on one side) for subroadbed. My lower hidden storage yard is 1/2" and it is solid. Yes, it's heavy, but I don't have to put braces in every 12". And any layout larger than 4'x8' is NOT really portable unless it is really modular. I sold myself that fairy tale and had to learn the lesson the hard way.

You could do what britbloke suggested, but I think that is more work and getting your hands up into that "conduit" to wire the center and outside rails could be problematic (I think). In some spots on my mainline, I am adding stiffeners (1" x 2" lengths of pine edgewise) under the subroadbed to gain rigidity. I'm having to work around the wiring (which is already in place) and it's a PITA.

Best,

George

NOW I feel stupid! This is something I could have helped you with, George, if I was only paying attention. (This just goes to show how disinterested I am in layout building.) Britbloke's suggestion is good, and will give the very strongest construction. If I may, I would only offer that it is perhaps more than is necessary.

When it comes to stiffening, people often make the mistake of thinking in terms of adding thickness. In reality, you get more stiffness by going deep, i.e., using a stiffener which is mounted perpendicular to your load bearing surface. In this case, the simplest, easiest, cheapest way is a "T" section. This has the added benefit of allowing wiring access, and use of foam, rather than plywood.

Interesting topic.

I guess curves could be handled with a bunch of straight sections.

Wayne, if Britbloke's luan will curve for a box structure, it'll curve for a "T" trunk. There are other materials that can curve, and be laminated, if necessary. On the other hand, your discontinuous angular assembly will add little or no extra strength to the roadbed on top, unless each joint is held together with brackets.

P.S. - Frankly, I think the Irwin Allen-esque "lightening" holes are undesirable, as they weaken the "T" trunk.

Roy wrote:On the other hand, your discontinuous angular assembly will add little or no extra strength to the roadbed on top, unless each joint is held together with brackets.

You make it sound like an ugly solution... as well as not strong. Well, I agree. I was thinking biscuit joints, but I don't think I would like the looks no matter how I joined the ends.

I have seen curved built up sub-roadbed in a magazine or on-line. That method is beautiful, but time consuming and requires a lot of clamps.

See below.

webenda wrote:
I have seen curved built up sub-roadbed in a magazine or on-line. That method is beautiful, but time consuming and requires a lot of clamps.

I agree Wayne.I quit after the third ply and cut it from plywood.

I used a 4'X8' sheet of 1/2" insulating foam that had foil on both sides for my Christmas layout.1"x 4" perimeter with similar cross-braces spaced at 24".
I have used it for six years with no sagging.When not in use it hangs from the ceiling in a storage shed.

Roger, Do you use the foil electrically? Or would that lead to a huge capacitance problem?

Regarding the time-consumption, fair enough. Instead of the luan, how about using cardstock or corrugated paperboard for the spine (what I've been calling the "T" trunk)? The advantage is its easy curvability, and the fact that you can build up plies quickly using a spray glue called Kraft Bond, without needing to clamp and let each layer set. Should be even lighter - especially the corrugated paperboard.

Roy,

Never gave that a thought.Just painted it.

Probably easiest to take George's advice, thicker sub-roadbed than 11/32 ply and more risers. However, other methods are fun to think about.
Here is an example using masonite splines. Easy to bend and can cut them on a table saw.

Reference: http://s145079212.onlinehome.us/rr/howt ... ndex.shtml