Page 17 - July August 1998

Preparatory Work
The track plan had already been drawn on the baseboard and this was first checked using the actual pointwork. Where neces- sary, small adjustments were made.
The original design contest had specified Peco track and points as these are the most widely used by modellers in the UK. Code 100 was used for the mainlines in order to conform to the NMRA’s module specifications. All other track and points are Peco Code 75. Transitions between code 100 and code 75 were constructed as shown in fig 7. The code 75 works really well with NMRA RP25 wheels and its finer profile contrasts with the heavier rail used on the mainlines. As described earlier, the mainline was also raised 1/8"using card roadbed to emphasise this difference.
All the turnouts have live frogs - Peco’s “Electrofrog”. The frogs are switched via electrical switches. Relying on the point blades for electrical contact is asking for trouble. Toggle switches are used to move the point blades and switch the frogs as shown in fig 8. There are two ways to wire live-frog turnouts as shown in fig 9. We used method B. The moving blades are bonded electrically to their adjacent stock rails. This avoids the risk of the back of a metal wheel touching the moveable rail and causing a short circuit. It also has a less obvious advantage. Suppose the switch which switches the frog does not operate properly - for example because of poorly adjusted linkage or a fault on a switch machine (point motor).
With method A a short circuit occurs because the point blades connect the frog to one stock rail while the switch con- nects it to the other. All you know is that there is a short somewhere on the layout - not too helpful! With method B there is no short. All that happens is that the frog is switched to the wrong stock rail. If the rest of the wiring of the layout is sensible it should be obvious that something is odd at this particular turnout - a much easier debugging proposition. Of course, method B is only possible if frog switching does not rely on the point blades. Some Peco turnouts already have insulated gaps in the appropriate rails and metal links under the rail which may be removed to make the electrical isolation at point X in the diagram. They also have gaps in the sleeper web to allow electrical bonding of the point and stock rails. Those which did not have these features were modified to this scheme during track laying.
The rails were bonded before the track was laid and the gaps cut afterwards. In fact all the track was laid without any breaks for sections, live frogs etc. Rail gaps were then cut in both track and points using a razor saw. No insulated rail joiners were used. Pieces of 0.015" styrene were superglued in each rail gap to prevent the rails closing up during expansion. Once set, the styrene was carved and sanded to conform to the rail profile - almost undetectable once the rail is painted. Normal, conducting rail joints
weight from an Athearn car. The magnet then “clamps” itself to this from under- neath while the glue dries. I have used epoxy, bath sealant and a hot glue gun for gluing. They all work fine. I prefer the hot glue as it is “instant”. The industrial track was to be laid directly on the chip- board surface so the mainline’s card roadbed had to be tapered down to it. This was done using a sanding block and coarse sandpaper. It exposed the soft inner core of the card which was strengthened by soaking it with Ronseal wood hardener. This is used nowadays by card modellers in place of shellac. If you use it, please make sure that everything is correct before applying the hardener to the card. The result is so hard that I haven’t yet found a tool that can work it effectively!
Before laying the track, all the bench- work and roadbed was given a coat of sealer in order to reduce the effects of humidity changes and of the water- based method to be used later to apply the ground-cover.
Tools
The following tools are needed for track laying...
Rail Cutters
There are several options. Bob used a razor saw for most of the work but you could use wire-cutter-style pliers (such as Xuron) or a cut-off wheel in a motor tool.
Swiss files
For cleaning up cut rail ends.
A selection of drills
If you will be operating the turnouts from underneath the baseboard a 3/8" is suitable. A 1/16" drill is needed for electrical feed wires.
Tweezers, taper-nose pliers
and wire strippers
The one-handed variety of wire strip- pers which cut the wire to length and strip the end in one action are very convenient.
Soldering Iron
At least 25 watts - and rosin cored solder.
AUGUST 1998 17
Tom Winlow