Improving a switchback

[Dan Watrous]

I have a steep switchback of about 35% slope and getting up it in a 4x4 is hard during wet season. Worse for my neighbor who has to keep climbing the hill.

I want to widen the shelf logging road so I can bring travel trailers up to a landing flat area, but this switchback is steep enough to require a tractor to get a travel trailer above this. The other switchbacks flat in the turn, so want to make this one like those.

Would you agree with decreasing the B segment slope by putting most of that rise into the last 80 yards of the segment A straightaway with a gentler slope, and careful compaction?

How do you find the kind of person that could visit the job site and consult on this?

 

[Willie B]

A switchback ought not have such steep grade. Turning on steep is tough! It takes a huge volume of gravel to build a proper switchback, but FAR less to back up one direction. A zig zag road cut into a steep side hill gets you up without huge volumes of material. you have to back part of the way.

A road built for skidders & dozers is going to be too steep for automobiles. Ask those with nice driveways on steep sidehills who they used, & prepare yourself, it will be a big job.

 

[skyking1]

Yes the first B road needs to be angled if at all possible to take the bite out of it, ending in a transverse flat along the topographic lines. Then back onto C, then drive onto the last climb. It is so much easier than a ginourmous fill as @Willie B has pointed out. It could become quite driveable that way. Big switchback sweeps are a real pain to build and also, when you are driving them in that corner the washboarding is inevitable and costly to maintain/fix.
Asphalt is about the only way to hold tight switchbacks.

 

[Dan Watrous]

Thanks for the ideas, will check the topography to see doing them

 

[MG84]

My rule of thumb when building switch backs is you shouldn’t be climbing on the corners. It does take more work to build that way but the finished product is nicer to drive and lower maintenance.