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Trail Construction and Maintenance Notebook
Next to waterbars, climbing turns are the trail structure most often constructed inappropriately. The usual problem is that a climbing turn is built (or attempted) on steep terrain where a switchback is needed. A climbing turn is built on the slope surface, and where it turns, it climbs at the same rate as the slope itself. If the slope is 40 percent, the turn forces travelers to climb at 40 percent. It is almost impossible to keep a climbing turn from eroding and becoming increasingly difficult to travel if the slope is steeper than 20 percent.
The advantages of climbing turns in appropriate terrain is that a larger radius turn (4 to 6 m, 13 to 20 ft) is relatively easy to construct. Trails that serve off-highway-vehicle traffic often use insloped, or banked, climbing turns so that riders can keep up enough speed for control (Figure 59). Climbing turns are also easier than switchbacks for packstock to negotiate. Climbing turns are usually less expensive than switchbacks because much less excavation is required, and fill is not used.
![[diagram] Climbing turn](images/fig059.jpg)
Figure 59—Climbing turns continue the climb through
the turn. They can be insloped or outsloped.
The tread at each end of the turn will be full bench construction, matching that of the approaches. As the turn reaches the fall line, the amount of material excavated will decrease. In the turn, the tread will not require excavation other than that needed to reach mineral soil.
Guide structures should be placed along the inside edge of the turn. Temptation-reducing barricades can be added if necessary. The psychologically perfect place to build climbing turns is through dense brush or dog-hair thickets of trees. Be sure to design grade dips into the approaches.
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