When PMT was started, it was decided to use HO scale,
16.5mm gauge. It was also decided that the club would be modular, i.e.. make
use of standard sized 'tables' with tracks entering and leaving at fixed
points. This works very well, and is a popular way for clubs to
build big layouts. As time went by modules were bought by the club. This
however led to high maintenance cost to repair and maintain the modules.
It was therefore decided to go back to the original concept of every
member, who is interested, owns his own modules. The size was reduced to
1200mm in length to make it possible to fit inside a normal passenger car.
The standards were changed slightly and can be found below.
New HO Gauge module standards
Modules should be built according to
the following set standards or can be bought from the club:
1200mm long by 600mm wide (See Fig 1)
Adjoining modules will be clamped
together by means of U profile which incorporates clamps. These U
profiles will also be used to accommodate feet of the modules. These
will be supplied by PMT.
Sides to be kept clear of any fixtures
except pockets on corners.
Height of the sides of the modules must
to be 100mm top to bottom.
Thickness of the wood is 12mm pine ply.
1 cross braces has to be added in
centre of modules for solid top modules. If top is extruded polystyrene
then 2 braces have to be used.
The legs are made from 25m square steel
tubing with an adjustable 10mm threaded socket in the top to adjust the
height as needed and a cap on the bottom. These will be supplied by the
club when erecting at exhibitions.
Facia's are to be added to front of
module starting 25mm from the bottom. Height above module to be a
minimum of 20mm. 25mm below facia is used for green curtain which are
supported by curtain spring with eye hooks on screws. (Obtainable from
PMT at a fee)
Corner modules will be 90 degree units
with an outside track radius of 36” and inside radius of 34”. These will
be supplied by PMT.
There is no height limit to the modules
(multiple layers are encouraged) modules have to fit through a 700mm by
2000mm door frame.
The scenery itself has to meet with
certain standards, namely:
Double track mainline, the nearest
known as the A-line (Front of module) and the other as the B-line. The
A-line (Analogue) traffic runs right-to-left and the B-line (Digital)
can be both directions.
There must never be any physical or
electrical connection between the A-line and B-line.
The rail end is terminated by means of
2” Atlas Snap track #454 with 1.5mm ABS spacer under Snap track.
Peco code 100 nickel-silver rail has to
be used on all main line track with no turnouts smaller than Peco medium
radius leading from the mainline
Any code 100 nickel-silver flex
(preferred) or track sections can be used on side lines.
The track has to be laid on a 5mm foam
sub-roadbed or 5mm cork.
Ballast to be used where possible is Woodlands
A bus wire system must be used, wired
into terminal blocks at both ends or as preferred. The bus is terminated
with Male 2 way connector on A-line and Female 2 way connector on B-line
on right of module and Female 2 way connector on A-line and Female 2 way
connector on B-line on left side of module. This is seen from the front.
If the module requires power for
automation or lighting, a fused transformer or power supply has to be
mounted under the module, and standard 3 point mains plug on a
reasonable length of cable is to be supplied. Power may NEVER be tapped
from the tracks for any function.
The wiring has to conform the Club
standards using purple, orange, white and green wires with purple the
first rail and green the fourth rail from the front of the module
Everything between the termination
tracks is left to the modeller's own initiative, subservient to the
approval of the Club's Technical Committee
Clearances has to be high and wide
enough to allow for the largest commercially made models in HO scale to
Over head wires are only used in
exceptional cases and then only on the A-line
The module sides must be painted tennis
See attached drawings for further