Ramp

[longisland]

Hi,
I post a similar question before; I hope to get better response after I refine my post. My friend is planning to build a ramp swith 2:1 (H:V) slope. The ramp is 20 ft run & 10 ft rise. I'm looking for charts or publications to check if a fully loaded 40 ft container truck can actually climb this ramp. I can't seem to find any chart or table in the green book for this gradient.

thanx in advance

 

[CarlB]

Short answer - NO!

I doubt AASHTO addresses grades steeper than about 15% (3 foot rise in 20 feet), as that's about the safe limit, or driveable limit. A dirt bike with spike wheels could make a 50% slope OK. In fact a 50% ramp sounds like a take-off for a car jumping show.

Besides being able to physically climb a slope, you need to see what change in grades a truck can make without dragging on the bottom. Maximum grade breaks for trucks are usually 15% to 20% - so for a 50% ramp you'd need gradual vertical curves before and after ramp.