helix vertical clearance

[guitarherowanab]

i think ive decided i need a helix at one end of my layout. it is only a single track, and it will be used to somewhat disguise a turnback by elevating the track along the wall behind the foreground track. ill post pictures soon for input. it has to be 25, no more than 26" radius. it will go round 1 and a half times, obviously, to send the track in the other direction. what should my endpoint elevation on the upper end be to have a balance between overhead clearance issues and not too riddiculous of a grade. i plan on running nothing oversizes, and no passenger trains. i have it set at 5.5 inch elevation difference between bottom and top right now, and in cadrail 3d, it appears to be enough clearance. it is at a 2.264% grade right now.


thanks


rob



rob

 

[lmackattack]

If i understand the question I think your asking how much room you need for a train to fit under the helex. It really depends on the type of trains your run and how long. I run 1950-60s era with nothing larger than a box car or train longer than 10 cars. I did however leave space under my bridges to bearly clear a double stack intermodal just in case I run one. the choice is yours for hight and you can reduce the grade by adding an extra loop. i think I gave my "over under" about 4" of elevation and did it withing a 2.5% grade.