What is L-Girder benchwork?

[Anonymous]

New people often have what seems like stupid questions to the rest of you, but I'm old enough not to care much anymore if people think I'm dumb for asking a question [:p]

What is L-girder benchwork? More specifically, what other kinds of benchwork are there besides L-girder? Obviously (I think) there is just a flat peice of wood to build a layout on as an alternative to L-girder, but what actually defines L-girder and what are other options than L-girder?

Thanks in advance, no laughing [:D]

[orsonroy]

In general, there are three types of layout construction:

1) tabletop. Add track to a flat board and start playing trains. A fairly new variation on basic tabletop construction is using polystyrene foam for the base instead of wood. The foam is easily carveable, meaning you can aviod the "pool table" look by carving terrain under the track level. Table top construction is experiencing a big revival, especially with modelers wanting long, narrow, linear layouts attached to the walls like book shelves.

2) box frame. Basically, build a box out of 1-by stock. This method is now most popular for building modular and sectioanal layouts, since it yields the most rigid layout support. Yards can be added to box framing with sheets of plywood (or foam or whatever), and the mainline can be added with strips of wood. Elevations can be added to the layout by adding 1-by risers to the box frame members, under the mainline.

3) L and T girder. This is the "wood lite" method of layout construction. Simply, you make a basic layout framework by building legs, and attaching 1-by stock to them which have been built into an L or T shape. Generally, these girders run the long axis of the layout. Individual girders are tied together with a few pieces of 1-by stock. Risers are added to the girders to support and elevate whatever you choose for your track and scenery.

Kalmbach publishes a couple of excellent books on layout benchwork that explain these different construction methods better than this simple post. If you're heading towards a layout that's more than a simple 4x8, I strongly suggest investing in these books!

[Anonymous]

The name "L-girder" comes from the principal horizontal members in this type of benchwork construction. The L-girders are assembled by attaching the side of one piece of lumber to the edge of another (usually by glueing). The girders are held together with clamps or screws until the glue dries.

Viewed from the end, an L-girder makes the shape of a letter "L". However, when the L-girder is incorporated into the construction, the "L" is upside down. (This way the the "flange" is on the top, making it easier to attach additional crosspieces to the top of the girder.)

As Ray indicates, most model railroad benchwork is built with 1" (nominal) lumber. A typical L-girder is built by attaching the side of a 1 X 2 "flange" to the (top) edge of a 1 X 4 "web."

The resulting girder is much more rigid than would be a plain 1 X 4 board.

--John

[ndbprr]

The reason an I beam is built the way it is is that the maximum compression and tension are where the flanges are and where the mass is needed. Wide flange beams recognize this and have been available for roughly the last fifty years or more. We obviously do not need the kind of support a steel I beam can afford us. However A 1x4 glued to a 1x2 is far stronger and will not sag as much as a 2x4 due to the distribution of the mass of the wood. Likewise a box beam made of 1x4's is far stronger than a solid 4x4 and a lot lighter.

[AltonFan]

I have heard that L-girder, while sturdy, economical with wood, easily adaptable to a variety of layout shapes and scenery profiles, and elegant from an engineering standpoint, it is very fragile, if one were to attempt to move parts of a layout. The tendency with L-girder benchwork is to design the layout's support system as a unified whole, making it very difficult to cut a layout into sections.

If moving a layout is in your future, a box frame may be a better choice.

[Anonymous]

Properly built, L-girder will be very strong. It should only look fragile. The theory behind it is that of a truss, in that lightweight members, properly braced take the place of stronger, more massive members. I've seen rickety box frame layouts and have built a rock-solid L-Girder layout.

Box-framing is no guarantee that a layout will be easy to move. I tried moving an ancient box-framed layout that was a nightmare. The up-front planning is critical no matter how you frame your benchwork, so plan for possible moves or even future revisions by making logical sections independent "modules."

Wayne

[Don Gibson]

'L Girder' Construction:
Is a support system made popular by MRR Editor Lynn Wescott that goes beyond the 'Table Top' 4X8.

Like Orson Roy said

QUOTE: Kalmbach publishes a couple of excellent books on layout benchwork that explain these different construction methods better than this simple post. If you're heading towards a layout that's more than a simple 4x8, I strongly suggest investing in these books!

AMen!

[CBQ_Guy]

Here's my two cents...

I have seen many layouts using what one could call L-girders in the construction of their benchwork, but strictly speaking it's not THE L-girder method as described by Linn Westcott (his creation, IIRC) in his Kalmbach book on the topic back in the 1960's. Nothing necessarily wrong with that, we do whatever seems reasonable or works for us. But since the original question in this thread asked what is L-girder benchwork, I just wanted to point out that it is an entire system or concept, not just the use of two girders stuck together in an "L" shape.

On another point, Ray Breyer mentioned three types of benchwork. I believe I've read a reference to another type a few years back which I think was called "stud wall", or "knee wall" or some such. I don't recall ever reading a description of exactly what this is or how to use it, though.

[cwclark]

I have photos in my webshot gallery showing what l girder benchwork looks like go to:img src=<"http://community.webshots.com/user/bayouman1"> click on trains and look closely at the photos...Chuck[:D]

[CBQ_Guy]

I am reminded of a couple L-girder points after looking at photos. The "system" is designed so all screws used in it's construction are accesible in the future and none are covered up (Someone mentioned a couple years ago that this is now a moot point since the introduction of the Sawzall!) Anyway, the joint creating an L-girder are to be glued and screwed, BUT "by the book", after the glue dries the screws are "supposed" to be removed. I cheated on mine and used nails and just left them in. The joists recommended in the book are 1by3's. The neat thing about the system is that the joists don't have to in a specific area or arrangement, in fact, they can be layed at various spacings or even on an angle. This allows max flexibility when planning for low areas in the scenery and also gives you the ability to shift them if needed in the future, if, for example the linkage or machine for a turnout ends up being right over the location of a joist. Remember, the screws are accesible from beneath the benchwork, so just just remove, relocate the joist, and re-screw at the new location.

Attached to each joist there is a riser screwed to it (1by2?), and a cross piece of 1by1 screwed to the face of the riser and perpendicular to it, even with the top of the riser. It is upon this assembly that the subroadbed is screwed, the screw coming up through the cross piece from below, again making the screws accessible for future relocation or dismantaling.

One thing I don't like about the system is all the cross-bracing needed on the legs (again if one is going "by the book"). I know it's sound advice, but IMO it's a PITA. Too much 1by2 to buy, and try to find some decent ones nowadays! Adds lots of expense and material to the project. They also get in the way A LOT if you're planning to use the underside of the layout for storage (I know from Xperience...). For my layout I am planning to use heavier lumber for the legs as well as L-girder legs as I have both laying around from past layouts and a lot I got for free years ago. Another L-girder system advantage is, since an L-girder is stronger than a single length of stick lumber, legs can be spaced farther apart, which of course means you'll need less. There is a table in Mr. Westcott's book giving the specifics on the possible spans between legs, depending on the size of lumber used in constructing the girder.

One other advantage to L-girder which I discovered years ago is that one wouldn't normally have to mess around putting leveling screws and TEE nuts into the bottom of each leg (another PITA, IMO). Of course this only applies to "permanent" type layouts. I just make sure the L-girders are level and at the same height to each other using a long level and some C-clamps, then just screw them to the legs.

[Anonymous]

QUOTE: Originally posted by AltonFan

I have heard that L-girder, while sturdy, economical with wood, easily adaptable to a variety of layout shapes and scenery profiles, and elegant from an engineering standpoint, it is very fragile, if one were to attempt to move parts of a layout. The tendency with L-girder benchwork is to design the layout's support system as a unified whole, making it very difficult to cut a layout into sections.

If moving a layout is in your future, a box frame may be a better choice.

A bit of planning can make it separable and movable...

My new layout is taking shape... 4x8 foot framing to left... 4x6 to right... 2x7 brdging the gap between... like 'waterwings' in the "Atlas " plans. total 8x45 feet.

Each part is connected and vividly marked (underneath) at the connection. A bit of stiffening (via adding a diagonal brace or sheet of ply along bottom) and they can be separated and moved ... just cut the rails on top... and away we go! (only if need be
.. mind you!)