Railroad Tie Retaining Wall Calculator

Overview

Estimates timber courses, tieback/deadman pieces, gravel, drainage pipe, fabric, spikes, and backfill from a straight wall length and height.

Assumptions

• The wall is straight with nominal tie dimensions.
• The estimate is a material takeoff, not a timber retaining-wall design.

Worked example

For a 20-ft wall built with 8-ft ties, each course needs ceil(20 ÷ 8) = 3 ties; a 3-ft height using 6-in courses needs about 6 courses, or 18 face ties before extras.

Common mistakes

• Using weathered ties with unknown condition.
• Omitting drainage stone and an outlet.

Limitations

It does not address preservative condition, connections, soil loads, or groundwater.

Safety and local requirements

Older ties may contain preservatives; do not burn or cut without suitable precautions. Verify local rules and consult a qualified professional for retaining structures.

Sources

• EPA — Soak Up the Rain
• OSHA — Landscaping and Horticulture