What are the pros and cons of L-girder benchwork

John, I found a few photos that might interest you, since you are doing similar work. There is no question in my mind that LG is the strongest, most dynamic and flexible construction system available.

Sorry, my photo captions did not come through

Photo 1   Cross Section of LG Construction showing fore and aft girders joists , risers and sub roadbed cantelevered by knee bracing

Photo 2 Stream cut in with lower level yard

Photo 3 Part of 40 feet of unobstructed benchwork

Photo 4 Shows ability to splice L-Girder and Tee into intersecting Girders

Daz, I used regular Lionel 3 rail O gauge. All I did was push brads into track than ballast and white glued them never once a loose track. Worked like a charm had space to cut down for lakes and rivers hot wired down a little for streets used plaster  and painted black, looked great attached accessory's with white glue and brads or screws never had a problem. trees went right in just 1 push though you couldn't play with them or you made the hole to big.. On one I even made my own trestles out 1x4 strips of wood (lots of angle cuts with zona saw)connected to 3/4 x 1/2 supports at track joints never had problem just crazy glued together ran heavy steam on them to.

Rich I think that would be a great idea as my problem now seems to be the "how" of building the actual bench work I mean I don't get the procedure. I looked on the internet yet all I see is guys explaining how their building their layouts not a breakdown of how their building their bench work. I wonder if the Westcott book breaks it down. I'm sure its not hard and i can figure it out but that's my only question left. Everyone here has been great with their helpful suggestions and clarified the pros and cons to the different bench work styles. Thanks a lot everybody.

Wiring from the top is easier, can be entirely constructed from plywood with little to no waste. Grades are easy to achieve with risers, valleys can be created easily by removing joists where necessary. No need to top with plywood. 

 Steve if you don't cover with plywood how would you hide the joists? if you just ran a strip under your track? This is part of my confusion. do you use the old cardboard and plaster cloth method?

Xray. awesome layout!!!!! But how will you fill in those open spaces now?

Skyhookdepot

Thanks for posting those photos. It shows how flexible the L girder technique can be. As I said in my post, my approach is a little different, in that the top of the cross members are the same height as the longitudinal girders.  In most other L girder construction the cross members sit on top of the longitudinal girders.  The entire layout is then built on risers to accommodate changes in elevation.   I did this to keep the fascia at a constant level so it does not appear in panoramic photos. I then bring the scenery down to the top of the fascia.

You also noted I am..."doing similar work." Actually my bench work phase is long completed. Here is the same view as  it currently looks. As I said,  the bench top is the same height as the fascia top:

Thanks for the explanation. I figured that's what you did, just wanted to confirm.

The 2nd photo from SkyHook's post shows how he covered the joists with plywood. As you can see, the base is covered and the 2nd level is on risers with cleats attached. Notice that there are no screws visible from the top, all screws are done from the bottom, one reason for the cleats. You might also notice that he has already cut out what appears to be a river on the 2nd level. The photo doesn't show how he intends to make the river bed, but if you need extra cross-members to support a river or lake bed, they can be added to risers set at lower depths upon which you can attach plywood, foam, etc.

If you just use plywood under the track, all you have to do is make the roadbed wide enough so you can attach landscaping materials, such as the cardboard/cloth you mentioned or wire mesh, to form ridges, valleys, etc. Or you can build up from the joists below with the same foam you've used on your other layouts. I intend to try layers of 1" thick foam so I can cut thinner layers closer to the final shape rather than do more "sculpting" with 2" thick foam.

I gotcha Dave so it is a scenery plus too to use l-girder bench work. I see some nice pics from John S. up above and he used kinda both methods with good results. I think i'm gonna give this a try I think I got it now, and I always know that if i run into any problems there are a lot of good knowledgeable people here to help me. But I think  should be fine.

From what I understand, it may take some trial and error, so don't bite off too much at once and don't get discouraged. Here's a You Tube video showing some of what I'm talking about when it comes to using foam. The foam part starts near the 2.5 minute mark.

http://www.youtube.com/watch?v=nKguw6NWtAI

Coincidentally, this new post by Tim Newman also shows why so many favor L-Girder construction. Had he built a regular open-grid table, it would have been much harder to make the changes he did. I "follow" Tim (along with several others) and I've learned so much just by reading their posts and viewing their photos. By following them, I don't miss anything either when I'm traveling, etc., their posts come straight to my Inbox.

https://ogrforum.com/t...11#25504494625006111

Well, that's an interesting question, one that I've been pondering myself for quite some time now. This is the reason why waaay back at the beginning of this thread I said I wouldn't use L-girder construction if I had to do it over again, although for this type of layout, it really was the only way to do it. What I mean is, if I had to do it over again, I would make a simpler layout.

When I built this section in particular I envisioned some pretty dramatic scenery, which is why the timber trestle is in place. But I came to the self-realization, after I started the scenery on the opposite end of the layout, (remember, I said that the layout is in the shape of a lower case "g" and this picture is of the upper loop) that I have absolutely no artistic ability and the scenery segment of this hobby is the most difficult part for me. So I figured I would "practice" on less visible portions of the layout and by the time I had progressed to the area pictured, I would hopefully have a better idea of what I'm doing. That may or may not happen.

In this particular area a fair amount of the lower level track will be in tunnels covered with hard-shell or extruded foam hills. I'll need a pop-up hatch so I can access the back portion of the area behind the timber trestle, so for that I suppose I'll use extruded foam as well. And then there will be some foam cliffs and rock ledges and such. It will have to evolve over time.

And by the way, to answer another question, the Linn Westcott book does show exactly how to do L-girder construction and and how it all goes together in sequence,  step by step. It will be a good investment, believe me.

Great Looking layout, John. I also have been finished with my benchwork for about 8 years and have never had a minute's trouble with it. Good luck.

Bob

Dave, for the river bed I used window screen stapled to the underside of the plywood sealed with glass cloth and West System Epoxy Resin.

Bob

Rick, sadly Linn Westcott has not been with us for over 30 years now; I don't think he is promoting anything.

Bob

Thanks, Bob, that's a great idea. I know some cover their layout with 1" foam and use another layer to form riverbeds, etc., but I like the idea of cutting the plywood to shape and adding the screening to form a more realistic riverbed. I also like the fact that your river is on the 2nd level, something I need to think about for my design.

Well that's the beauty of the LG construction method, and it's the only method that permits cutting directly into the plywood sub roadbed to form rivers, gulleys streams etc. Otherwise, as you stated, you need to artificially pack everything with foam to give you clearance for the topography you want. The more that is understood about LG the better it looks.

Bob

quote:

The actual bench work I mean I don't get the procedure. I looked on the internet yet all I see is guys explaining how their building their layouts not a breakdown of how their building their bench work.

I did around the room, so wall brackets first



Then set the L Girders upside down with "L's" out. Join them end to end with screws and a 12" cleat



Upside down L girders don't want to stand up to well so I made these brackets to hold them upright



Set the joist. Use a string line to keep them straight, if you want them straight. Set the first and last accordingly then pull the ones between to the line.  I went every 12", you could probably go 16". Wire chases optional in joists. Attach the joists up through the L, front and back with 2 screws. Note the cleat under the last joist holding the L girders



Here a began stepping the joist out for a wider section of the layout. The fascia will attach to the joist. I'm using bending plywood for the curved areas if I ever get to that point.



Here's a mock up of a curved fascia, you can glue up several layers to gain the thickness.

quote:

Steve if you don't cover with plywood how would you hide the joists? if you just ran a strip under your track? This is part of my confusion. do you use the old cardboard and plaster cloth method?

Scenery hides the joists. I use cardboard hot melted joist to joist and then plaster cloth to support scenery.  Most scenery is pretty light weight.

I used 3/4" ply and homosote for the sub roadbed. Regardless of what someone tells you, don't use 1/2" plywood for the roadbed, use 3/4". It's much flatter and stiffer than 1/2". A Union Pacific big boy is HEAVY. Save money elsewhere on the layout. You can use risers attached to the joist for grades and elevations.

Hope this helps

Steve, 

Excellent!  Well explained and written.

I love your layout, watched many of your youtube clips.  Wish I had the space you have!

Thanks!

there's more than one way to skin a cat. 

Steve thanks a lot that was just what i was talking about but 1 more question, when you screw the joists up from the bottom don't the want to say if leaned on fall down like the domino effect for lack of a better word.. I mean if you pushed on 1 of those joists wouldn't it be flimsy so to speak?

Xray that's awesome I'm loving that layout. I'm sure you'll pull it together nicely

Hey Jack, anything can go wrong in model railroading  ! I think you'd be surprised by how stiff they are. Keep in mind the sub road bed gets screwed in from the top too which really adds to it's over all strength. I just did a small build for a friend and he had the same concern until we fastened them to the L's. He's a believer. 

True plus the fascia and ply roadbed. Sounds like a plan and once again thank you so much the pics and explanation were perfect. Enjoy you building stage, to me its therapy when i get engrossed in building a new layout i go at it all day my wife has to pull me away from it but to me that's my favorite part. 

Originally Posted by DoubleDAZ:

there's more than one way to skin a cat. 

Yes, there is and you skinned it rather well.

You can also mount the "L" girders on cantilevers.  The dropped span is for a valley.

Hi! with L girder construction, your scenery can easily be dropped down to the floor!

think of the possibilities! Scenery that can dwarf your trains! Bridges that have meaning.

I'm thinking that is what Tom Tee is doing. Search for Patrick's layout pics. Have FUN!!

I didn't use L-girder benchwork on my layout, as pointed out above. At the time I was building my benchwork I didn't know how to do L-girder construction so, wanting to run my trains and quickly as possible, I used the method I did know...plywood and 2x4's. It worked fine for me, but the next time I build a layout I will use L-Girder as it's more flexible. So if you're building a new layout my advice would be to take some extra time and use L-Girder construction.

One nice benefit to the plywood and 2x4 method, however, is that it's incredibly heavy and sturdy....so I'm able to walk on top of table to do a lot of the work....which is necessity in my particular situation. L-Girder is fantastic as far as the layout design goes, but I'm not sure a 250 pound man can walk around on it like I do with my current layout. But, as I said, I'd still go with L-Girder if I had it to do over again because overall it is a better method.

Thanks,

Eric Siegel

Eric, you have seen mine and the girders themselves could support my 215 pounds, though the track base would not be able to. But, what is nice is that you do scenery from back to front or side to side and you can get to your spots from underneath and stand to complete the work. Not even a Top-Side Creeper needed. Good to hear from you and thanks for the updates on the continued progress on your great layout.

Rick

I built my L-girders out of 3/4 plywood strips I found in a Builders Surplus Store.  The were 16' X 2 1/2" X 3/4.  I screwed and glued them together to form the L and spanned a 28' opening.  I added a couple legs for added support.  I spaced my cross pieces every 12 inches screwed them in from the bottom and covered the top with 3/4" plywood.  I have been on top of the bench work and I'm pushing 325#.  I found a source for Styrofoam that I used to elevate part of my track six inches.  I used Woodland Scenic risers on one side and had blocks of foam tapered for the risers one the other end.

Late to the discussion here. One thing to remember is that L-girder benchwork does not necessarily have to be open grid.

You can take advantage of the custom-shaped, smooth-flowing curved edges provided by L-girder, but top the joists with sheets of plywood cut to follow the contours established by your joist length. You don't have to cut and use only the narrow roadbed strips associated with open grid.

This can be seen on some portions of John Sethian's layout as shown in his photos way back at the beginning of this thread.

Jim

So, to dumb it down...L girder is really just a long span/fewer floor supports foundation for the upper framework/type of your choice....right?{I'm new at this concept}

...along with more control over the contours of the benchwork such as curved ends,

...plus less precision needed in cutting joists to length (They do not have to fit precisely within the 1x4 side rails used in other construction.

...the jury is still out IMO as to whether less lumber is required as some report.

Jim

In my opinion, The L-girder is a stronger, straighter and probably lighter RAIL than other materials. I've never seen strength tests, but I'd be willing to bet an L-girder rail made from 1x2's/1x4's is stronger than a 2x4, especially over longer spans, is more resistant to warping, etc.

However, the L-girder SYSTEM is far more than just the rail and allows much more flexibility while maintaining strength, particularly with grades and landscaped rivers, lakes, canyons, etc. Just study the photos that have been posted, especially the ones by SkyHook on Jan 29. While that can all be done to some degree with more standard grid methods, it is far easier with L-girder. It is also much easier to make changes because all screws are done from below, so they are accessible "after" landscaping has been applied.

As for being "the best", IMHO there are simply NO bests of just about anything. Everyone has their favorites, but there are several ways of constructing benchwork that will last the life of a layout. I believe Linn Westcott would agree with that. He designed a system that works well, who knows what he might have come up with if he were still with us? I wonder what method Woodland Scenics "thinks" is the best? Or Mianne?