Clearance Observations and Solutions. - Printable Version

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Clearance Observations and Solutions. - Academy Staff - 08-26-2011

This commentary on clearances was posted by "George" on Dec 3, 2001 in our old Academy. Note that there are no pictures, but the thread was good enough for our Academy before, so we are posting it here as well.

Re: Clearance Observations and Solutions. - Academy Staff - 08-26-2011

Clearance Observations and Solutions from Georgeā€¦.
Clearance is always a problem. Just when you think the problem is solved at one trouble spot, it rears it's ugly head in another form elsewhere. Let me share with you a little pain, history and a few solutions I've come up with over time.

I suppose everyone has purchased, or was given the Atlas Bridge Pier set at some point of life. It's unfortunate that the largest size piers (which aren't very high) are the only ones that fit the bridges they manufacture. Too bad they don't make the larger, wider size in a variety of heights for other manufacturers bridges. Too bad they don't make multiple track bridges as well! Too bad! These piers of various sizes and undersized shapes are a blessing or a curse when it comes to clearance.

I remember the first time I added an Atlas bridge with associated piers to a layout back in 1970. Moving from a 4X6 board to a 5X10 board and using flex for the first time, I was pumped! The results were really pleasing with the terrain I was making then, and for the first time things trundled along as I imagined they should on such a project.

The moment of truth came when the first train pulled away from the station. Soon enough, that Bratwurst eating grin was wiped off my face when my "HO" scale Burlington Northern Budd dome slammed into the Atlas bridge it was attempting to glide underneath.....CRACK!! The pier I had selected and installed was too short, and it was the tallest one! To add insult to injury, when the same passenger car went around the curve on top leading into the bridge, the corner caught on a bridge support. The bridge was too close to the curve!

I had to tear out all my hard work.

That disaster was my wake-up call regarding clearances. Sometimes it seems you can never provide enough clearance. Whenever I install a tunnel portal, or a bridge pier now, I check for every INconceivable possibility. Look at all of your friends who had to tear out scenery, piers and portals done to perfection. All this because they wanted to run double stackers, or suddenly became obsessed with catenary and decided to add it.

Another rule of thumb I've lived with in the past from this disaster, ADD MORE. Do you like doing perfect chicken on the grill? Think it's cooked? Let it go for ten more minutes! You're always glad you did. Ditto with clearances. Not only measure, but also do a mock-up. Seeing is believing. Even when the numbers add up, you still should take a look at the impending result, before you drive the first screw or glue anything down. If it doesn't look as you've imagined, go back to the drawing board and save yourself a lot of work and grief.

Another personal rule of thumb.....Since 1975, whenever I plant a portal or sink a pier, I always shim it up. Whatever comes from the store or whatever you create, give it more room. I shim up my piers and portals 1/4 of an inch with small pieces of wood that are then concealed with scenery matter, be it stone or weeds. You can even go half an inch. The result in 1992 was that all my clearances were suddenly fashionably "Container Compatible", unlike most people, if I wanted containers or not! Now like most people, I do run containers.

I tore apart an apartment layout in 1987. Moved, rebuilt and "dismantled" again in 1995, and am currently "recreating" and adding on extensively. I got so sick of moving and the associated cost of rebuilding, that I did my best to recycle everything. Here's an example while speaking of clearances.

Try making a housing for your tunnel portals for easy removal to access derailments, or simply for cleaning. I'm no carpenter, so here's the easy way. Take 1X2 lengths. Cut and nail or glue three sides corresponding to the extreme outer dimensions of the portal. I took a plaster double track portal which I hand painted and detailed and glued such a wooden frame with Elmers to the inside of the portal ON THE REAR, not the sides. Then, I made another three sided frame to fit around the first frame which I attached to the tunnel portal. The outer frame was then screwed to the bench work making for a nice, solid foundation. VOILA! The tunnel portal has a sleeve it firmly plugs into for easy removal. Loose scenery is laid around the seams to hide them, and there's no disaster when one needs access to the inside of a mountain. With this double track portal, I can get my entire arm inside to my shoulder if I have to, thanks to the portal sleeve. Last time I moved, that mountain went to the gulls, but the portal and it's sleeve housing came with me for the next layout. A tip to avoid tunnel derailments - Put a re-railer track inside!

Making a long story short for track clearances, stick with this. On curves of under 32" radius, down to 18" as the tightest, keep your tracks a minimum of two inches apart from the track centre. This way, there will be plenty of clearance without side swiping for your full length passenger cars, auto parts cars, 100 ton cranes and anything else the industry comes up with in the future.

Going back to my dome collision with the bridge support, any bridges or trackside structures, including straight platforms should be at least one foot away from any curve. Also, NEVER begin any super elevation to a curve any less than eleven inches from the beginning of the curve.

Clearance need not be a problem. Don't put the cart before the horse, calculate your clearance problems first. Solve them and make the terrain fit the solution. Solve the problem and pad the solution slightly in anticipation of the unknown whenever possible.

In 1970 with the railroads in decline, who would have even remotely imagined that a clearance would ever be required for anything higher than a dome or a high-cube boxcar? In 1970, I took a wild guess and have been glad ever since.

Stop, Look and Plan ahead. It saves time and trouble.