GW broad gauge

[drduncan]

What track centres are recommended for GWR broad gauge? (4mm scale)

Thanks

Duncan

[BG John]

For what standards?

 

The BGS Data Sheet SM/1 (formerly 01.2) recommends the gauge and six foot, not centres. For S4/P4, the gauge is 28.08mm, and 6 foot is 24.83mm measured between the insides of the rail. So 52.91mm centres.

 

For the not recommended EM or OO standards it's a bit less clear, so ask again if you need those.

[drduncan]

Hi John,

Thanks. I currently work in EM and would want mixed gauge so I'm tied into those rail standards.

D

[BG John]

For EM the recommendation is the same as S4/P4, but some people have used a narrower gauge. I don't know if there are any problems fitting the wider wheels in some locos and rolling stock, but suspect there may be. 27.15mm gauge is also mentioned in the same Data Sheet, as this is reduced in proportion to the underscale gauge of EM. The "scale" 6 foot works out as 23.998230mm (!), but a BRMSB standard of 27.00mm is shown alongside it. I haven't checked, but assume this is the BRMSB standard for EM.

 

Assuming you use 28.08mm gauge, other standards you need now for EM are:

Gauge widening 0.20mm

Check gauge 27.08mm

Crossing flangeway 0.97mm min, 1.00mm max

Between check faces 26.15mm

 

Effective flange thickness 0.56mm

Back to back 26.38mm min, 26.48 max

Tyre width 2.30mm min, 2.45mm max

Check dimension 27.04mm (Back to back + Effective flange thickness)

 

For 27.15mm gauge I think you need to make it up yourself.

 

I hope that helps, and doesn't create more confusion! I was using EM before I started modelling the broad gauge, but my BG (and mixed gauge) modelling has all been in S4/P4. Fortunately my EM is early 1900s, so that wasn't a problem.

[garethashenden]

Now this is a project I can get behind. Looking forward to see what you come up with!

[drduncan]

I have 13ft to play with, so I'm looking at 4x3'3" boards. I'm leaning towards a through station, but 2 fiddle yards eat up half the space. That said, I'm only looking for a small branch line. I intend to run my pre 1904 stock as the standard gauge option and build up a collection of late BG stock, especially convertible locos and coaches. I'm trying to draw up cutting files for some 6 wheel BG and NG coaches as well as some 40ft convertible brake tri-composites.

D

[BG John]

Cutting files for a Silhouette, or for something else? Just asking out of interest, in case you were thinking of sharing the results .

 

I'm moving my BG modelling period forward to the late 1880s, as I can adapt quite a lot of narrow gauge stock, like Triang clerestories, and Coopercraft wagon kits. I'm keeping my early 1900s EM stock, and have a part built layout for it, but I'm planning to move my NG modelling date back, and do it in P4 in the future.

 

Don't forget to join the Broad Gauge Society!

[drduncan]

Cutting files for a Silhouette, or for something else? Just asking out of interest, in case you were thinking of sharing the results .

 

I'm moving my BG modelling period forward to the late 1880s, as I can adapt quite a lot of narrow gauge stock, like Triang clerestories, and Coopercraft wagon kits. I'm keeping my early 1900s EM stock, and have a part built layout for it, but I'm planning to move my NG modelling date back, and do it in P4 in the future.

 

Don't forget to join the Broad Gauge Society!

The intention is for a silhouette or similar, but I'm using inkscape so it may be possible to have them laser cut in rowmark.  If you have a silhouette or laser cutter I'm sure we can do a deal...drawings for cutting services etc.

 

I will be joining the BGS as a matter of urgency!

 

D

[The Stationmaster]

For what standards?

 

The BGS Data Sheet SM/1 (formerly 01.2) recommends the gauge and six foot, not centres. For S4/P4, the gauge is 28.08mm, and 6 foot is 24.83mm measured between the insides of the rail. So 52.91mm centres.

 

For the not recommended EM or OO standards it's a bit less clear, so ask again if you need those.

 

Which sounds as if they are recommending an accurate 'six foot' as it was actually 6ft 2.5ins measured between the running (inside) edges of the rail according to a drawing in MacDermott

[K14]

Which sounds as if they are recommending an accurate 'six foot' as it was actually 6ft 2.5ins measured between the running (inside) edges of the rail according to a drawing in MacDermott

 

If my maths is correct it's 6' 2-3/4", according to this extract from the Contract Drawing for the South Wales & Glo'ster & Dean Forest Permanent Way :—

 

 

(maybe MacDermot skipped the sacred 1/4"?).

 

This may be of interest too:—

 

 

Note that it's Broad & Mixed Guage - either a nod to IKB's French ancestry, that or the tracing was made by an ancestor of Arthur Bostrom

 

Pete S.

[melmerby]

According to "Great Western Way" the 1838 spec is 6' 2½" between the outside Inside rail faces (Bridge rail, baulk road) by 1880 it had risen to 6' 6"

 

Keith

 

EDIT: Correction

[PaulT]

I have 13ft to play with, so I'm looking at 4x3'3" boards. I'm leaning towards a through station, but 2 fiddle yards eat up half the space. That said, I'm only looking for a small branch line. I intend to run my pre 1904 stock as the standard gauge option and build up a collection of late BG stock, especially convertible locos and coaches. I'm trying to draw up cutting files for some 6 wheel BG and NG coaches as well as some 40ft convertible brake tri-composites.

D

Glad to see your BGS application request.

If you draw up cutting files for any vehicle for which we dont provide a kit, I hope you will consider making it available to other BGS Members. Contact me about this when you are ready using the email address on the application form. Doubtless our data sheets will help you with drawings.