High cube, car carriers & NMRA clearance gauge

Tom Tee posted:

If I extend the side and top edge of the NMRA standars gauge to bisect, eliminating the beveled top edges,  will that permit passage of oversize cars?  If not what do I need to add?  Where?t

You might inquire of the NMRA standards folks..............and get an answer, someday.

I'd just extrapolate as you were thinking and go with it.

I think you've got the right idea Tom, by extending the height and squaring it off. Is this just for a single spot at the yard entrance, or are you looking to apply it generally to more of the layout?

Is the track straight at the entrance?

Is it possible to have an opening of 6" high above the rail and 4" wide? That's a scale opening of 24' x 16'. If the track is straight , you could cut down the width.

Double stacks are Plate H.  Here is a link to the Plate H drawing : http://www.icrr.net/plateH.jpg

Some western roads use 20'8" instead of 20' 3" for height

That's good to know Jim. Even though I'm a 3 railer, I use the MTH double stack as my height gauge for clearance. Even if you 2 railed that car, and knocked off a 1/4" it would still be the tallest.

So, Plate H would be roughly 5-1/4".

Thank you for the replies.

Elliot, the close setting is only in one spot as shown in photos.  This is one of four hidden staging yards.  It looks like all I need to do is to relieve a scosche off the +/- .00000" fit.  Perhaps 1/4" will suffice, could go more.  The support is essential.

Jim, I think you answered my second question.  From the notes on plate H, the gauge does not show the minimum of an opening but rather the maximum of the equipment.  One still needs to allow a safety margin for clearance I am guessing.  One scale foot, 1/4" as above???