G Scale Standards

G Scale Standards

SCALE/GAUGE NAME 'G' Scale Prototype

SCALE 1:22.5 1:1

TRACK

Track gauge 45mm 1012mm (3ft 4in)

Rail profile - Gauge 1 Tenmille Scale Brass Flat Bottom or Bullhead Grooved girder

Rail profile - LGB LGB or Peco Code 250 Grooved girder

Groove width, straight track - Gauge 1 2.25mm 1 1/4in

Groove width, straight track - LGB 3mm 1 1/4in

Groove width, curved track - Gauge 1 2.75mm 1 1/2in

Groove width, curved track - Gauge 1 3.5mm 1 1/2in

Minimum radius curve, older trams 375mm 45ft

Minimum radius curve, modern trams 530mm 66ft (20 metres)

Double track distance apart (track centre lines) 150mm Minimum 8ft 6in

WHEELS

Recommended either to Gauge 1 commercial available wheelsets Gauge 1 Commercially available wheelsets ------

OR to "G" Gauge commercially available wheelsets. "G" Gauge Commercially available wheelsets ------

Back to back Gauge 1 41.5mm ------

Back to back LGB 39.5mm ------

Axle diameter Gauge 1 3.18mm ------

Axle diameter LGB 6mm ------

OVERHEAD

Minimum height above road (scale) 270mm 20ft

Height for LGB overhead above rail 226mm ------

Wire type and diameter Phosphor - bronze 20swg Copper 0.32in

Wire type and diameter Plated steel 2mm dia -----

Length of traction pole above ground (scale) 340mm 25ft

Length of traction pole above ground LGB 300mm ------

Distance apart of traction poles on straight track 700mm (average) 120ft(maximum)

Distance apart of traction poles on straight track LGB 600mm (average) ------

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


SCALE/GAUGE NAME	'G' Scale	Prototype
SCALE	1:22.5	1:1
TRACK
Track gauge	45mm	1012mm (3ft 4in)
Rail profile - Gauge 1	Tenmille Scale Brass Flat Bottom or Bullhead	Grooved girder
Rail profile - LGB	LGB or Peco Code 250	Grooved girder
Groove width, straight track - Gauge 1	2.25mm	1 1/4in
Groove width, straight track - LGB	3mm	1 1/4in
Groove width, curved track - Gauge 1	2.75mm	1 1/2in
Groove width, curved track - Gauge 1	3.5mm	1 1/2in
Minimum radius curve, older trams	375mm	45ft
Minimum radius curve, modern trams	530mm	66ft (20 metres)
Double track distance apart (track centre lines)	150mm Minimum	8ft 6in
WHEELS
Recommended either to Gauge 1 commercial available wheelsets	Gauge 1 Commercially available wheelsets	------
OR to "G" Gauge commercially available wheelsets.	"G" Gauge Commercially available wheelsets	------
Back to back Gauge 1	41.5mm	------
Back to back LGB	39.5mm	------
Axle diameter Gauge 1	3.18mm	------
Axle diameter LGB	6mm	------
OVERHEAD
Minimum height above road (scale)	270mm	20ft
Height for LGB overhead above rail	226mm	------
Wire type and diameter	Phosphor - bronze 20swg	Copper 0.32in
Wire type and diameter	Plated steel 2mm dia	-----
Length of traction pole above ground (scale)	340mm	25ft
Length of traction pole above ground LGB	300mm	------
Distance apart of traction poles on straight track	700mm (average)	120ft(maximum)
Distance apart of traction poles on straight track LGB	600mm (average)	------
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

'G' gauge is a scale gauge ratio that was developed by LGB in the 1970's. It is a narrow gauge system and was originally designed for garden use.

TRACK

For scratch building track then the Tenmille brass flat bottom or bullhead rail is recommended, either soldered to large copperclad sleepers or directly to brass countersunk screws fixed into the baseboard at appropriate places. Peco offer a flexible Gauge 1 track and parts for points. Many modellers using the coarser wheel standards make use of commercially made track, either LGB or Peco 'G' gauge flexible track. Points are available by both these manufacturers.

Many modellers use the two rail system of power supply. However, it is also possible to operate using a live overhead supply. In this case the rails can be electrically bonded.

WHEELS

While the width of tramcar wheels is much less than railway wheels, with a smaller flange width and depth, in 'G' gauge modelling it is usual to use the commercially produced wheel sets. Gauge 1 wheels are a little over size, but are recommended. Some modellers use the LGB standards which are rather too large, but will be compatible with Peco and LGB pointwork.

OVERHEAD

LGB make an overhead system for their trams, but it is very much lower than scale. It is impossible to get a double deck tramcar under it. Parts for scale tram overhead are produced by Model Tramway System (MTS).

POWER SUPPLY

The standard power supply is 12 volts DC, using model railway controllers. The recommended controller is the electronic feedback type and the handheld (HH) from Gaugemaster has been used with great success. It requires a separate 16 volt AC supply from a transformer (also available from Gaugemaster). The controller is very small and can be carried around the layout with ease.

The way tramways are operated in 'G' scale is by using either a live overhead system or a two rail power supply. In the live overhead system the power is fed through the overhead and returns via the rails, just like the prototype. However, there is one major difference between model and the real thing. In the model the overhead is one continuous electrical supply. All sectioning is done through the track. This makes modelling much easier and prevents stalling on overhead dead spots. The two rail system is exactly like that used for model railways.

LINKS FOR WHERE TO GET EVERYTHING

'G' gauge items are produced by LGB and Bachmann and are available from specialist model railway shops (see the advertisements in the Railway Modeller).
A range of 'G' gauge tram and overhead parts to TLRS fine scale standards are produced by Model Tramway System

TRAMWAY AND LIGHT RAILWAY SOCIETY

The Tramway and Light Railway Society is a registered national charity founded in 1938 by those interested in trams and modelling trams. There is an advisory service for 'G' scale modellers.

For details of application contact the Membership Secretary

List of TLRS standards for other scales.

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