Build a Layout Access Gate
text and drawings by Dave Roeder, MMR |
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 Like many model railroaders, I have been around long enough
to see quite a few layouts. There are also many different
benchwork designs and track arrangements. The current trend
seems to be the walk-in around the walls design. This is
best from the access standpoint since it allows unlimited
entrance/exit.
But there are also those who for various reasons do not want
to loose the space required to turn trains around at each
end of the entrance to a walk-in design. Most walk-in
layouts have a return loop at each side of the entrance. The
use of a duckunder is not a good solution. They limit
access and are a hazard to tall folks.
A properly designed gate allows easy access without any
drawbacks. The key to building a successful gate is in the
design and construction. A good design takes into account
not only access, but expansion/contraction, safety, and ease
of maintenance. The gate on my HO scale Webster Groves and
Fenton Railroad has all of these features. The design takes
into account change due to temperature and humidity.
The features are as follows:
-
 Hinges are standard interior 4 inch length with 4 wood
screws in each plate.
- Door latch is a standard interior model with European
style handicapped handles.
- Spring tension device is a bolt or roller type as used to
remove play from screen doors or as used on sliding doors.
This device pushes the door latch mechanism back against the
flat side of the latch striker plate. These can be found at
most hardware stores in the door hardware parts aisle.
- Adjustable tee-girder roadbed made from Ύ plywood. For
HO scale, the track roadbed is a piece cut to 3 Ύ X 28
which is strengthened by a piece of 3/4 X 7/8 X 27 long
piece of white pine set on edge.
This tee section is supported on four pieces of Ό-20 UNC
threaded rod. These are set into the top rail of the gate
using Ό-20 nut inserts of the type used for leveling legs on
furniture. Flat washers and hex nuts are used to attach the
roadbed section to the top rail. These four assemblies
provide vertical adjustment for the tee section of roadbed.
See figure 1.
- The adjustable track section provides adjustment of the
gap between the latch end of the gate and the fixed track on
the layout. This track section is made from an Atlas re-
 railer
/ grade crossing which has been modified to allow Ό lateral
adjustment of the gap at the latch end of
the gate. The Atlas re-railer is permanently attached to the
layout on the fixed section of the layout using small wood
screws. The section of the re-railer attached to the gate is
also attached with four wood screws, but the holes in the
rerailer for these four screws are slotted to allow plus or
minus 1/8 lateral adjustment. On the gate end of the re-railer
a 6 section of Atlas code 100 or code 83 flextrack is
added. The ends of the rails are notched vertically 1/2
using a flat file. There must be one left hand and one right
hand slip rail end on each rail to form the expansion joint.
One end of the track has slip rail joints on the re-railer
section. These mate with corresponding slip rail joints on
the fixed track attached to the gate roadbed. See figure 2.
- The track on the gate must be wired as a separate block.
Wires dropped down from the fixed and the adjustable track
sections will insure good performance and reliability. These
wires must be routed through the hinge post with enough
slack to permit the gate to be fully opened. Make sure the
holes through the roadbed for the adjustable track section
are elongated ½ to allow adjustment.
- Mechanical interlocks at each end of the fixed track work
on the layout prevent accidental crashes off the end of the
gate opening. These are made from Tortoise switch machines
mounted horizontally. Power to operate these is provided
through a DPDT limit switch mounted so
as to be triggered by the closing or opening of the gate.
The stop rods are made from coat hanger wire .062 diameter.
One end is hammered flat for a distance of Ό, then a
.031dia. Hole is drilled in the flat to clear the tortoise
activating wire. I use .020 diameter music wire in the
tortoise switch machines. A hole is also drilled through the
roadbed in the center of two ties to clear the rod. Wire the
switch machines to raise the rods when gate is open. See
figure 3.
- General construction: The gate is made from 2 x 4 lumber
for the frame. The hinge post and latch post are 4 x 4
lumber. It is important to securely attach both posts to the
floor. Concrete anchors or equivalent are required. Another
solution is to place a 2 x 6 flat on the floor and attach it
with liquid nails. The gate does not need to go all the way
down to the floor. The bottom sill plate on the gate can be
centered between the two hinges. This gives plenty of
strength and still allows you to crawl under in the event
that you need to get out with the gate
closed. See figure 4 for general location of components
keyed to these instructions.
One final note: This gate has been in use since 1995. I have
adjusted the gap at the latch end about once a year. The
leveling studs need attention about once a year as well. I
added a de-humidifier to my basement after talking to a
friend of mine and found it to be a good investment. The
drier air eliminates seasonal humidity changes on the
layout.
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