Hydraulic Shoring

Hydraulic shores are aluminum rails and cylinders that push against both trench walls to hold them in place. Unlike a trench box, shoring actively supports the soil. It’s light, quick to install from the top, and common for utility trenches.

• Construction
• Utility contractors
• Plumbers

How it works

• Each shore has two vertical rails connected by one or more hydraulic cylinders.
• The shore is lowered into the trench, and the cylinders are pumped up from the surface to press the rails against the walls.
• Pressure holds the soil in place. Some systems lock mechanically after pumping.

Installing

• Install from the top. Nobody enters an unshored part of the trench to set shores.
• Follow the tabulated data for shore size, cylinder size, and vertical and horizontal spacing for your depth and soil type. OSHA’s Appendix D tables or the maker’s data apply.
• Start at the trench entry and work forward, so workers are always inside the shored area.
• Use sheeting (like plywood or fin forms) behind the rails in loose or raveling soil, as the tables require.
• Pump to the required pressure and check each cylinder holds.

Removing

• Remove shores from the top, in reverse order, starting at the far end and working toward the exit.
• Release pressure slowly and lift shores out with a hook or line.
• Backfill as shores come out, so no one is exposed. See Backfilling & Compaction.

Inspect

• Cylinders hold pressure; no leaks
• Rails not bent, cracked or corroded
• Pins, collars and fittings in place
• Spacing matches the tabulated data
• Sheeting in place where required
• Trench walls between shores not raveling or bulging

A competent person must inspect daily and after rain or other changes. See Competent Person Inspections.

Last updated: October 2, 2026