What is an undercut line and what is it used for?

What is an undercut line and what is it used for?

• A. A trench to drain water
• B. A trench to install safety lines
• C. A trench and berm, used to stop rolling material
• D. A burn line used for control

Answer: (C)

An undercut line is a trench at the toe of a slope paired with a berm to intercept and stop rolling material before it reaches the fireline. The trench provides a low point where debris can settle, and the berm acts as a barrier that blocks further movement downslope. This combination helps stabilize the slope and protect the control line from rocks, soil, or other material that might roll onto it. It’s not about drainage, installing safety lines, or a burn line for control; its purpose is specifically to prevent rolling debris from reaching and compromising the line.

An undercut line is a trench at the toe of a slope paired with a berm to intercept and stop rolling material before it reaches the fireline. The trench provides a low point where debris can settle, and the berm acts as a barrier that blocks further movement downslope. This combination helps stabilize the slope and protect the control line from rocks, soil, or other material that might roll onto it. It’s not about drainage, installing safety lines, or a burn line for control; its purpose is specifically to prevent rolling debris from reaching and compromising the line.