[MasonsDad]

Hi Gang, I know this question has been asked here before , however I couldnt find it to retreave the answers.
I am building double track Truss type bridge and was wondering what the average clearance is between the 2 inside rails?
 would 2 inches be enough?

 

[Guest]

i don't think so.
in my opinion a width of 150mm or 6" is the absolute minimum on straights (based on LGB rolling stock) the outside measurement of 45mm track (G-gauge) being 50mm or 2", there is an overhang of 2" on each side of the track.
so you would need 2 times 2" between tracks. for 1:20.3 even a bit more.
(maybe, if you are modelling 1:32 it might be slightly less)
or in other words - a doubletrack bridge should need 12" width between the insides of the trusses. - for a really tight fit.

 

[JerryB]

Track spacing is usually expressed as centerline to centerline distance. Typically something around 15' on prototype standard gauge tangent track. For modeling, this roughly calculates to:

1:32 scale: ~5 5/8"
1:29 scale: ~6 1/4"
1:20 scale: ~9"

You don't mention your scale or whether standard gauge or narrow gauge equipment, but using your 2" dimension between the inside rails, the centerline spacing would be ~3 3/4". I'm certain that would be too close for all but the smallest narrow gauge equipment.

Happy RRing,

Jerry

 

[Torby]

17 ft.


I put them 9 inches center-to-center, or more precicely, right rail to right rail.


Sorry, I can't help you with the space between the ears/DesktopModules/NTForums/themes/mls/emoticons/tongue.gif

 

[Schlosser]

FwiW, even LGB couldn't decide what was best. Two R1 switches, used as a cross-over, put the tracks on 181mm (6.33 inch) centers. Two 90 degree crossings put the tracks on 184mm (6.45 inch) centers. Haven't measured their 30 degree crossings but expect they'd be similar to the R1 measurement.
'
Keep in mind that this is or was 'based somewhat' on meter gauge prototypes, not standard gauge. 14 foot centers on old time standard gauge would yield 7.47 inches in Gummi scale (1:22.5). New standards are wider, sometimes as wide as 25 feet between mainline centers. And long cars on tight curves demand a greater distance between centers than what is needed on parallel straight tracks.

Art

 

[MasonsDad]

Thanks Guys I will put all this info to work