Looking for bridge info

[Rico]

Im looking at getting a double track plate girder bridge to replace the ones I have with incorrect track spacing. (incorrect in that they don’t match up with my double track bridges)
Im thinking of the Atlas HO scale model #70000028 code 83 double track plate girder.
Can anyone tell me what the track spacing is, my searches are coming up blank.
Thanx in advance!

 

[Selector]

I don't see that kind of detail specified anywhere, but looking at the photo, it looks to be 2" on centre. I use the apparent separation of the rails and extrapolate to the distance to the other centreline. Two inches looks very close....to me.

 

[Rico]

Thanx Crandell, I was extrapalo extropalt extroplolo guessing two inches as well!
Funny thing is I have three different double track bridges and they all have different spacing, even from the same manufacturer! I’m aiming for two inches.

 

[GeeTee]

I believe the NMRA spec for parallel tracks is around 2 1/8" - 2 1/4" , I seem to remember it being slightly over 2"?

 

[cv_acr]

I believe the NMRA spec for parallel tracks is around 2 1/8" - 2 1/4" , I seem to remember it being slightly over 2"?

That's more like recommended minimum spacing.... and yes you can do 2" spacing, but not if there's something in between. You'll have to add a bit of clearance for the width of the girder.

So, yeah, if you like up a through girder like this with something like a double track truss, it's not going to work because the truss is going to have a tighter spacing.

If you want to get something lined up with an existing truss bridge, ditch the idea of looking for double track through girders like this and get a pair of deck girders, where the entire bridge structure is below the rails. You can easily put two of these side by side at virtually any spacing.

 

[GeeTee]

I checked the NMRA, minimum is 1.8" for 1920 - 1969 or 13 scale feet. 2 1/8 -2 1/4 minimum is what you get from an Atlas No. 6 . without adding spacers in a yard .

The hard spec would be whatever crossovers/ double crossovers your going to use , if you use them.

 

[cv_acr]

The hard spec would be whatever crossovers/ double crossovers your going to use , if you use them.

The hard spec in this case is clearance for that bridge girder sticking up between the tracks. You can trim the ends of a switch to adjust spacing.

 

[Rico]

Thanx guys!
And good... no great point about the center clearance, I hadn’t thought about that!
Deck girder bridges will work just fine and can be made cheaply by cutting the middle section out of an old atlas plate girder then inverting them.
N scale plate girder bridges placed upside down make a good short-span deck bridge with strip styrene on the outer edges.
Here’s one from an old layout, HO in the center with N bridges on the ends: