Baseboard Construction

This article is making its first appearance here on the net.
By Stephen J Chapman.

The baseboard on which you build your model railway is one of the most important parts of the model railway. With most other parts of the model, if you get something wrong, you can simply remove the track, scenery, or other feature containing the mistake and replace or rebuild it as required. Not so with the baseboard. If you make a mistake in the way you construct your baseboard you will have big problems. The board may warp or in extreme cases even collapse if it isn't built right thus doing major damage to the other parts of the model railway or at least making it very difficult to operate properly.

Fixing baseboard problems is not easy to do after the event. It is extremely difficult, if not impossible, to repair a badly warped baseboard without damaging the track and other features which have been built on the board. The only real solution to a warped or otherwise badly damaged baseboard is to completely rebuild it. This results in all of the effort that has been put into laying the track, wiring, and scenic work has been lost. You will have to start over again. How much better to get it right in the first place.

 

Some beginners think that all you do to build your baseboard is to buy a sheet of pineboard, possibly six foot by four foot (1.8m x 1.2m). This with little or no support is their baseboard.

Of course no one reading this makes that mistake. We all realise that a baseboard needs a supporting frame to stop the board from warping.

The next thing that some beginners think when they realise that a frame is necessary is to decide that all sorts of complicated woodworking joints are necessary to join up the pieces of timber that make up the frame. Of course you can use these fancy joints if you want to but it is not absolutely necessary.

A baseboard can be built with fairly simple joints. We will consider the construction of simple baseboard frames which can be used for most layout designs. Other methods of construction are possible and may be dealt with in a separate article.

 

Let us begin by considering each of the places where the timber supporting your board needs to be joined in order to construct a simple frame baseboard.

The Corner
Figure One

The first of these places is the corner of the board where the edge timbers of both edges meet. Figure one shows two simple ways to join the two together. The second way shown involves slightly more timber and slightly more time in cutting but avoids the need to screw into endgrain. Either of these joints glued and screwed will be quite satisfactory. Even just screwing the joint together will normally do the job of holding the baseboard rigid. In each case where screws are used, a pilot hole should be drilled through at least the first piece of timber.

The Edge
Figure Two

The next joint to consider is where the cross supports meet the edge of the board (figure two). The distance required between the cross supports will depend on the type of surface that you are intending to use on top of the frame. Pineboard or plywood of over 3/8 inch thickness (1cm) will be quite well supported by cross supports at two foot (60cm) intervals. A softer board will require bracing at nearer intervals, perhaps one foot (30cm). Again screws (and perhaps also glue) is all that is required to hold the joint together.

A Simple Frame
Figure Three

 

If you are using a sufficiently rigid surface to support your track and your board is not overly wide then you can get away with needing cross supports in only one direction. This will result in your building one or more frames similar to figure three (perhaps using different types of joints).

A wider board will require cross supports not only across the board but also lengthways. The joints where these lengthwise braces join the edge of the board can be exactly the same as along the other edges of the board. What do we do however to handle when the bracing crosses in the interior of the frame? There are two solutions here (figure four). We can stagger the bracing so that the bracing does not actually go straight across the board and use simple butt joints. Alternatively we can use a halved joint to cross one brace through the other. Both of these methods are equally successful in creating a strong baseboard. The final appearance of a frame built using each of these two methods will be similar to that shown in figure five.

Interior Joints
Figure Four

 

So now we have a simple frame. All that needs to be added is the baseboard top on which the track and scenery will be placed and legs to hold the frames at an appropriate height off of the floor.

Before adding the baseboard tops and legs the various frames should be placed together. This will enable us to check first of all that the baseboards will fit in the available space and secondly that the boards actually fit together properly and that you haven't built them all to significantly different sizes and left a gap in one side.

Wide Frames
Figure Five

If a non-permanent method of attaching the boards together (for example bolts or split hinges) then the boards can be actually attached to one another to check that they fit.

Whether it is better to fit the legs next or the baseboard top depends on whether you intend to be able to separate the boards again once the entire baseboard is erected. If a permanent layout is to be erected with there being no intention of being able to separate up the boards again then the legs can be added next and the baseboard top can be placed directly onto the erected frame ignoring baseboard joins. Most modellers will find it useful even with permanent layouts to be able to dismantle the layout into its component boards should that become necessary (for example to repaint the room) and in this case it is easier to put the baseboard top onto each board separately and the legs can be added afterwards.

 

So let's move on to consider the baseboard top. This can be an all over top the same size as the frame onto which it is screwed. This is the simplest top to install. You simply obtain a piece of pineboard, plywood, or other suitable board (not masonite or plasterboard) of the appropriate size, place it on top of the frame and screw it in place.

Open Top Board
Figure Six

The major advantage of a solid top board is that the board is fully supported by the frame both around the edge and in the centre ensuring that it remains absolutely flat. The major disadvantage is that the board is absolutely flat. A flat area is required where the track is going to be but the surrounding scenery should normally have variations in height. This is more easily achieved by using an open top board. This is a baseboard where the top surface of the board is only placed where the track is going to go (figure six) and the rest of the frame is initially left open until the scenery is ready to be built. This has the advantage of encouraging variations in the height of the scenery both above track level and also slightly below. The only difference that needs to be taken into account during the construction of the frame is that as the top surface may not be supported as fully as when a closed top is used, the cross members will need to be spaced slightly closer together. Also for very narrow sections of board it may be worthwhile to consider providing a lengthwise support directly under the centre of the board.

Low Level Support
Figure Seven

Only laying the board where the track is to go also has another advantage. Not all layouts have all of their track at the same level. Some layout plans have one or more tracks climbing up over other tracks. Gradients can be far more easily achieved using the open top approach. It is quite a simple matter to screw a small block of the appropriate height onto each of the crossmembers where the gradient crosses the crossmember (figure seven) and to screw the baseboard top down onto it. The thickness of this block can vary from a piece of a piece of ply perhaps three millimetres thick through to a piece of two by one laid on edge giving a height of about 25mm. If the crossmembers are about two feet apart (60cm) then if the baseboard top is fixed directly to the frame at one crossmember and is on a 3mm block at the next then we have a gradient of approximately one in two hundred. Few layouts have space for gradients shallower than this but if required pieces of card can be used to provide packing between the baseboard top and the frame. So we don't have a problem in providing supports for track anything up to 25mm above the normal board height.

High Level Support
Figure Eight

What do we do however when we want to take the track higher than this? Even in N scale this is insufficient clearance for one track to pass over another even if we leave the track unsupported where it passes over the lower track. So now what we do is to screw uprights to the frame where the baseboard top is to go. These uprights should extend above the frame to the required height. The baseboard top can then either be screwed directly into the top of the upright or if you don't like screwing into endgrain then another block can be screwed crossways against the top of the upright either above the original crossmember (figure eight) or if there is as yet insufficient space because you haven't yet got high enough on the gradient to attach it on that side then to the opposite side of the upright. Don't forget to take into account the displacement from the original crossmember position if any when calculating the gradient.

One other thing that needs to be done when attaching the board to an open top frame, particularly when a number of heights of board are to be attached, is to attach the boards together in pairs as you take the trackbed from one frame onto the next. This way you can be sure that the board will line up both horizontally and vertically when the entire framework is finally attached together.

Another possibility worth considering when building baseboards with an open top frame is to put two by one blocks under all of the trackbeds to raise it 25mm above the frame. This will then give more scope for scenery at levels lower than that of the track.

All of the blocks and uprights to support the trackbed should be fitted before the trackbed itself is fixed down. The board for the trackbed can then be laid in place and the gradients checked to see that they are correct. Adjustments to block and riser heights are easier to make at this time.

Once all of the risers are correct the trackbed can be screwed down although it is advisable not to screw down the sections where one track will pass over another until after the lower track is laid.

A Triangular Frame
Figure Nine

 

This completes the construction of our simple baseboard frames and the method by which a flat or variable height track surface can be attached to it. This form of construction will cope with most layout designs using rectangular frames. On those rare occasions when a baseboard shape other than rectangular is required then something approaching the required shape can be obtained by effectively chopping off the corner off of one or more boards. Of course we don't literally build the board and chop off the corner. Instead we construct the frame with the corner missing. Simply cut the two sides of the frame shorter where the triangular section is to be. The rest of the frame can be constructed as for a normal rectangle. An additional crossmember in one or both directions may be required to attach the edge firmly to the rest of the frame. Finally a piece of frame can be attached diagonally across the missing corner completing the frame (figure nine). By leaving corners off of several of your rectangular baseboards some rather irregular shaped layout can be built.

Curved Frames
Figure Ten

Curved baseboard edges- are not easy to build into transportable baseboards but can be added into permanent structures once the frames have been attached together by cutting a number of slots into the back of the piece of timber before screwing it into place (figure ten). Alternatively a different form of baseboard construction called L-girder can be used which allows us to have a permanent layout having no straight edges at all.

Baseboard supported by 4 legs
Figure Eleven

 

There are a number of ways of supporting your model railway baseboards. You can sit it straight on the floor, on a bed or table, or design it to rest across the various pieces of furniture found in your lounge. Most people however prefer to have the layout self supporting either freestanding on its own legs or alternatively, for fixed layouts, bolted directly to the wall.

Baseboard supported by 2 legs and a wall bracket
Figure Twelve

So let us now consider how we can make our layout self supporting. We will definitely need legs along the front edge of the board and the back can either be supported on another row of legs (figure eleven) or can rest on a timber ledge bolted to the wall (figure twelve).

Legs can be two by two timber or even two by one. The actual length to cut may be slightly less than your proposed layout height if you are intending to rest the layout on top of the leg framework or if you are adding adjustable feet to the bottom. Except in cases where a precise layout height is required (ie. to fit over or under some fixed object) the exact length of the legs is unimportant. Cut all legs at the same time so as to ensure that they are all exactly the same length. An exception to this requirement is where you are going to deliberately set one board lower than the others to allow for extensive scenery below track level (eg. a bridge or viaduct). Carefully mark any legs cut to a different length from normal so that they can be clearly identified.

 

The next step is to determine how the legs are to be attached to the layout.

Pair of legs with cross bracing
Figure Thirteen

For a permanent layout which fits exactly into its room simply bolting the legs under the corners of the boards will provide adequate support. This is a situation (as stated before) where it is better to fit the legs before adding the baseboard top since once the back of the board is resting on its ledge the legs can be attached to the front edge after using a level to ensure that the board is flat. Any imperfections in the floor will result in part of the leg projecting above the frame where it can be easily removed.

Leg hinged to underside of baseboard
Figure Fourteen

 

Portable layouts require more work in adding legs. In this case the legs will require cross bracing to ensure that the whole structure is stable when free-standing. This can be easily achieved in one direction by assembling the legs together in pairs (figure thirteen). These pairs of legs can then be attached to the underside of the layout.

Methods for attaching legs on a portable layout include (but are not limited to) bolting them in place, hinging them to the underside of the board (figure fourteen), or arranging it so that the board sits tightly down on top of the leg assembly by either building a box structure into the corner of the frame to hold the leg or onto the top of the leg assemblies to hold the two frames (figure fifteen).

Side view of legs showing box arrangement on top into which boards will be placed
Figure Fifteen

Once the legs assemblies have been built and attached to the boards, the layout can be erected on its legs. While erecting the layout, additional cross bracing can be added in the opposite direction to that already added (figure sixteen). This cross bracing should be held in place using bolts or split hinges since it will need to be able to be removed when the layout is dismantled.

 

Additional diagonal bolted in other direction
Figure Sixteen

So now the baseboards are complete and ready for tracklaying to commence.

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Copyright Stephen Chapman