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3/4 inch to 1 foot or 1/16 scale Standards |
SCALE/GAUGE NAME | 3/4" to 1' | Prototype |
---|---|---|
SCALE | 1:16 | 1:1 |
TRACK | ||
Standard track gauge | 3 1/2in | 4ft 8 1/2in |
'Narrow' track gauge | 2 5/8in | 3ft 6in |
Rail profile | Flat Bottom - Gauge 1, Course scale Gauge 0, G or 1/2in scale | Grooved girder |
Groove width, straight track | 3/32in | 1 1/4in |
Groove width, curved track | 1/8in | 1 1/2in |
Minimum radius curve, older trams | 3ft | 45ft |
Minimum radius curve, modern trams | 5ft | 66ft (20 metres) |
Double track distance apart (track centre lines) | 8in | 8ft 6in |
WHEELS | ||
Recommended to TLRS standards (see notes below) | TLRS | ------ |
Back to back Standard Gauge | 3 5/16in | ------ |
Back to back 'Narrow' Gauge | 2 7/16in | ------ |
Axle diameter | 1/4in or 5/16in stepped down to 1/4in | ------ |
OVERHEAD | ||
Average height above road | 15 3/4in | 21ft |
Wire type and diameter | Phosphor - bronze 20swg | Copper 0.32in |
Length of traction pole above ground | 18 3/4in | 25ft |
Distance apart of traction poles on straight track | 7ft 6in (average) | 120ft(maximum) |
Distance apart of traction poles on curved track | As required | As required |
Position of overhead wire relative to track, trolley poles. Straight track | Over centre | Over centre |
Position of overhead wire relative to track, trolley poles and pantographs centrally mounted on long bogie cars (like Blackpool). Curved track. | Over inner rail | To a complex formula |
Position of overhead wire relative to track, bows and pantographs over bogie pivots. All track. | Over centre | Over 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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