Question for the engineer types.

On standard gage, the rail is set nominally at 4'8-1/2". The wheels on a standard gage car are 4'8-1/4".

If I am going to set down two pieces of rail for a 3 foot gage railcar, what is the normal space between the rails? If the rail is at exactly 36", then what is the spacing on the wheels of the railcar?

Thanks

A.N.

tnold@northtexastransport.org

Andy, unlike some street railway profiles there isn't a sharp demarkation between tread and flange. If you look at standard wheel profile and gage drawings you will see the rail is just a little outside of the tighter radius going from the tread taper into the flange. They aren't Swiss watches and anything close will probably work just fine.

What narrow gage stuff are you proposing to run?

Dave

irondave@bellsouth.net

I generally build 3' gauge display track at 36 1/2 inches.

Jason Midyette

> Question for the engineer types.

> On standard gage, the rail is set nominally
> at 4'8-1/2". The wheels on a standard
> gage car are 4'8-1/4".

> If I am going to set down two pieces of rail
> for a 3 foot gage railcar, what is the
> normal space between the rails? If the rail
> is at exactly 36", then what is the
> spacing on the wheels of the railcar?

> Thanks

> A.N.


Boulder County Railway Historical Society
amjm@indra.com

>Andy; Wheels are mounted at back to back distances set by the AAR originally and by the
FRA today. I don't have the figures for 3' gauge but the figure for SG is Min. 4'-5 3/32", Max
4'-5 1/2" measured at the base line of the tread.
Operators pressing on wheels would press on one wheel using a gauge from the end of the axle. The
other wheel would then be pressed on using a
back to back gauge that fit over the wheel flanges. The pressure required to press the wheel on had to be within a certain range so the fit
would not be too tight or too loose. This varied with the axle rateing, 30 ton, 40 ton, etc and in
most wheel shops was recorded on a tape along with
the wheel number and was kept in the shop records.

I can't put my hands on the numbers for NG but
this will give you the general idea. Back to back
dimensions are important because of switch and crossing guard rails and switch frogs. On a wheel set with too wide a guage the guard rail might not be able to pull the wheel set over far enough to keep the opposite wheel from climbing the switch point.

Jim

Question for the engineer types.

> On standard gage, the rail is set nominally
> at 4'8-1/2". The wheels on a standard
> gage car are 4'8-1/4".

> If I am going to set down two pieces of rail
> for a 3 foot gage railcar, what is the
> normal space between the rails? If the rail
> is at exactly 36", then what is the
> spacing on the wheels of the railcar?

> Thanks

> A.N.


rrfanjim@mvn.net