This my first layout with one track crossing over another. I am using Lionel Fastrack O gauge. My question is what is the minimum clearance for tracks crossing over other tracks?
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One half inch over your tallest piece of equipment.
OK so what is the tallest piece of equipment that I might buy in the future. Someone told me that it should be a min 6 inches. I know scale cars are taller than some of the others and engines are different sizes. I just thought there was a set min that would cover everything.
Plan on the future. Stack cars, cube cars, etc all take a lot of vertical space. So think of what kind of rolling stock you plan on running.
See the attached NMRA recommendations, but they are not "gospel." If you run a piece of equipment with some part up (like a trolley pole or a crane), even 8" might not be enough. Also, note that measurement is from top of lower rail to bottom of support for upper level.
Chuck
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That is a tough question. Tstark was correct in his answer. However, you must design your layout to accommodate your future plan. It is all on you. MTH double stacks are more than 6 inches tall.
The issue with making all your clearances 7 inches is that it may necessitate steeper grades and will it be necessary to plan such clearance if your tallest piece is 5 inches?
I do think that generally the best piece of advice is as Tstark wrote. Ultimately, it is your decision.
PRR1950 posted:See the attached NMRA recommendations, but they are not "gospel." If you run a piece of equipment with some part up (like a trolley pole or a crane), even 8" might not be enough. Also, note that measurement is from top of lower rail to bottom of support for upper level.
Chuck
Thank you Chuck
John C. posted:That is a tough question. Tstark was correct in his answer. However, you must design your layout to accommodate your future plan. It is all on you. MTH double stacks are more than 6 inches tall.
The issue with making all your clearances 7 inches is that it may necessitate steeper grades and will it be necessary to plan such clearance if your tallest piece is 5 inches?
I do think that generally the best piece of advice is as Tstark wrote. Ultimately, it is your decision.
Thank you John,
Keep in mid you need about 14' of track running length to get up and over 6" with any type of decent acceptable grade. Go up to 7-8" of clearance and this goes up considerably. Point is, you need a bit of space to make an up and over happen.
14 ft. of run is a very good number to start a grade. This is about 14 ft. and a relatively steep 3.8%
Level difference about 7".
Doing the math:
Rise divided by run = grade
At 3% grade - 6" rise divided by .03 (grade) = 200"
200" = 16.67 feet of run
If you want 7" of clearance - 7" at 3% grade = 233.33" or almost 20' of track run to get up and over. I just wanted to point that out because it may be a factor. Maybe not, of course it depends on your available space and track plan.
If you have the space, then obviously the more clearance the better to future proof your purchases of rolling stock. However, many of us have to live with limitations and those often restrict the equipment we can run. TSTARK is right, 1/2" higher than your tallest piece of rolling stock is a good guide. However, while 6" of clearance requires about 16' to get an acceptable 3% grade on a flat table, it can also be achieved in about 8' by having one track go up 3" and the other one go down 3".
5-3/4" up to 7" if you want to run a rocket launcer with the boom raised 
And one other thing to consider, if you want the underside to have 6" clearance, you still have to take into consideration your underlayment for the track. If you have 1/2" plywood or homasote under your track, you are actually raising the track 6 1/2" off the deck, which increases the run. This is similar to the first time I cut stair stringers and didn't account for the first tread. Then you recut it and it's never as good as the first cut. If you catch my drift. Good luck getting up and over. What goes up, must come down. Having Oddessy helps, but is not necessary for the enjoyment of the sport. Cheers.
The grade is going up to a reversing loop , so going down is on the same track. I think it saves space that way. Might be wrong. Grade start ascending right after the switch. As far as I can figure the grade to get to 7 inches clearance will be <5%. The red section is elevated and it is there where I need clearance. Pretty steep. I guess that's why Lionel called it the big climb.
Thanks for all the info
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You can make that work. I counted 16 track sections at about 10" each = 160" approximately. Maybe it's a bit more, which would help. It can be tricky starting the grade right after the switch, which doesn't help. it'll be a bit steep, but what the heck, it's better than not building it. Good luck.
7"/160" = 4.375% grade
It's not advisable to start a grade right after the switch, so I started it after the 5" straight track. Not sure why you think you need the Red track to be at 7" when they don't cross over the bottom tracks until the curve before the switch going into the upper reversing loop. Here's a rendition done in SCARM. The Blue track is at 0" elevation, the Green track is at 7" and the Orange track has a grade of 4.1%.
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Sweet. Certainly doable. You can use manual switches at the return loops to save a few bucks if you want. The Fastrack manuals work really well in that application.
DoubleDAZ posted:It's not advisable to start a grade right after the switch, so I started it after the 5" straight track. Not sure why you think you need the Red track to be at 7" when they don't cross over the bottom tracks until the curve before the switch going into the upper reversing loop. Here's a rendition done in SCARM. The Blue track is at 0" elevation, the Green track is at 7" and the Orange track has a grade of 4.1%.
The layout that I posted a picture of is from Lionel. They show the elevated section in red but do not give a height. I just picked 7 inches so I wouldn't have to adjust it in case I get some equipment that would be too tall to make it under the bridge. If I build 1/2 inch above my tallest piece off equipment and then down the road buy something that I like that's taller by 5/8 I have to adjust. Trying to avoid that.
Thank you for your service and the info
I have made it 5" in the past. That is why 14' of run was on my mind. But that was all I needed. 7" is actually pretty high. But maybe that is what you need.
Now the next fun part is figuring out how many and how high each riser needs to be cut to go under your track and roadbed to get your consistent rise. Like a riser every 6". What is the increment? As always, it is simple math.
DoubleDAZ posted:It's not advisable to start a grade right after the switch, so I started it after the 5" straight track. Not sure why you think you need the Red track to be at 7" when they don't cross over the bottom tracks until the curve before the switch going into the upper reversing loop. Here's a rendition done in SCARM. The Blue track is at 0" elevation, the Green track is at 7" and the Orange track has a grade of 4.1%.
Thanks for the advise, I changed where the grade starts and stops. Makes a difference.
DoubleDAZ posted:It's not advisable to start a grade right after the switch, so I started it after the 5" straight track. Not sure why you think you need the Red track to be at 7" when they don't cross over the bottom tracks until the curve before the switch going into the upper reversing loop. Here's a rendition done in SCARM. The Blue track is at 0" elevation, the Green track is at 7" and the Orange track has a grade of 4.1%.
I like the idea you put up here and if I have the elevated section lowered to say 5 1/2 inches. I started the incline after the 5 inch section. 179" to 5 1/2" comes out to 3.25% or so. More doable. Thanks for the conversation.
Hey Everybody thanks for all the input. Taking all the comments into consideration I decided to lower the red section down to 5 1/2" Made everything better.
Thank You,
Just remember that the 5 1/2" doesn't account for any sub-roadbed you add under the elevated track. Both the graduated and elevated FasTrack trestle sets are 5 1/2", so if you plan to use those, you should be okay. Here's a 3D rendering:
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MTH 8-piece elevated trestle system has 6.5" of clearance and is just barely enough for MTH Realtrax and a Husky Stack car.
