TLRS 3/4 inch to 1 foot or
1/16 scale Standards

SCALE/GAUGE NAME 3/4" to 1' Prototype
SCALE1:161:1
TRACK
Standard track gauge3 1/2in4ft 8 1/2in
'Narrow' track gauge2 5/8in3ft 6in
Rail profileFlat Bottom - Gauge 1, Course scale Gauge 0, G or 1/2in scaleGrooved girder
Groove width, straight track3/32in1 1/4in
Groove width, curved track1/8in1 1/2in
Minimum radius curve, older trams3ft45ft
Minimum radius curve, modern trams5ft66ft (20 metres)
Double track distance apart (track centre lines)8in8ft 6in
WHEELS
Recommended to TLRS standards (see notes below)TLRS------
Back to back Standard Gauge3 5/16in------
Back to back 'Narrow' Gauge2 7/16in------
Axle diameter1/4in or 5/16in stepped down to 1/4in------
OVERHEAD
Average height above road15 3/4in21ft
Wire type and diameterPhosphor - bronze 20swgCopper 0.32in
Length of traction pole above ground18 3/4in25ft
Distance apart of traction poles on straight track7ft 6in (average)120ft(maximum)
Distance apart of traction poles on curved trackAs requiredAs required
Position of overhead wire relative to track, trolley poles. Straight trackOver centreOver centre
Position of overhead wire relative to track, trolley poles and pantographs centrally mounted on long bogie cars (like Blackpool). Curved track.Over inner railTo a complex formula
Position of overhead wire relative to track, bows and pantographs over bogie pivots. All track.Over centreOver centre

NOTES

Our online Beginners' Guide to Large Scale Tramcar Modelling gives pictorial details of the construction of tramcars in 3/4" to 1' scale.

TRACK

The recommended rail is flat bottomed in a choice of Gauge 1, Course scale Gauge 0, or 1/2in scale. For garden lines brass rail is essential and the larger 1/2" scale should be used. It is spiked to wooden sleepers or directly to the baseboard. Alternatively for indoors layouts Peco "G" scale rail soldered to copper clad sleepers can be used.

WHEELS

The width of tramcar wheels are much less than railway wheels, with a smaller flange and flange depth. TLRS standards should be used. These are available from their Model Engineering Secretary and drawings are included in their publication "Large Scale Tramway Modelling An Introduction and Guide by Peter Hammond and Peter Howard". Also consult the trucks section of our on-line Beginners' Guide.

Wheels can be turned from castings made by the TLRS. Pre-turned disc wheels, truck sideframe castings, 24 volt d.c. motors are available from the TLRS.

OVERHEAD

In 3/4" scale most modellers scratch build all their overhead parts, but items for tramway overhead are obtainable from Model Tramway System. Phosphor-bronze wire to 20swg. Copper wire should be avoided as it stretches. For garden use a thicker wire may be preferred.

POWER SUPPLY

The standard power supply is 24 volts DC, and controllers and powerpack have to be built by the modeller. However, some modellers have used a lower voltage and the heavier current type of model railway controllers as favoured by G scale users, such as the Gaugemaster 10LGB or 10LGB5. A 24 volt pulse width power unit and notched controller is available from the TLRS to order.

Live overhead is always used. Here the power is fed through the overhead and returns via the rails, just like the prototype. All sectioning can be done through the track as in model railway practice, or can be by splitting the overhead into sections.

LINKS FOR WHERE TO GET EVERYTHING

List of TLRS standards for other scales.



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