Hydraulic shoring is a trench support system made of aluminum rails held against the trench walls by hydraulic cylinders. Pumping fluid into the cylinders pushes the rails outward and preloads the soil, holding it in place before it can start to move. It's a support system under OSHA's excavation standard, so it must be used within Appendix D to Subpart P or the manufacturer's tabulated data.
The parts
| Part | What it does |
|---|---|
| Rails (uprights) | Vertical aluminum members that bear against the trench walls |
| Hydraulic cylinders | Horizontal struts that extend under pressure to push the rails apart |
| Pump and hose | Hand pump that pressurizes the cylinders through a quick-connect fitting |
| Release valve | Lets fluid out so the cylinders retract for removal |
| Wales (in some setups) | Horizontal members that let shores support larger areas or sheeting |
| Sheeting (such as plywood or FinForm) | Panels that keep soil from raveling between shores in weaker soils |
Why crews choose it
- Installed and removed from the top. Nobody enters an unprotected trench to set it.
- Lightweight and fast. Two workers can carry and set most shores.
- Active support. Preloading the soil limits movement, which matters next to roads, foundations and utilities.
- Flexible. Shores can be spaced to suit soil and depth, and combined with sheeting.
Installation, step by step
- Classify the soil and confirm depth so you pick the right spacing from Appendix D or the manufacturer's tabulated data. See soil classification.
- Dig a short section of trench. Install shores close behind the excavation; OSHA requires installation to be closely coordinated with digging.
- Lower the shore into the trench from the top using the installation pole or the machine, with rails against the walls.
- Pump the cylinders until the rails are tight against both walls, per the manufacturer's pressure instructions.
- Set the next shore at the required horizontal spacing, and add vertical shores, wales or sheeting where the tables call for them.
- Install the ladder inside the shored area and enter only the protected zone.
Removal
OSHA requires support systems to be removed in a way that protects workers, starting at the bottom and progressing upward, with backfilling progressing together with removal (1926.652(e)). With hydraulic shores, workers typically backfill and compact to just below the lowest cylinder, then open the release valve from the top with the pole and lift the shore out, working back along the trench.
OSHA rules that apply
- Designs must come from Appendix D, the manufacturer's tabulated data (kept at the jobsite), other approved tabulated data, or a registered professional engineer.
- Deviations from manufacturer's data require the manufacturer's written approval.
- Members must be securely connected to prevent kickouts.
- Excavating up to 2 feet below the bottom of the shores is allowed only if they're designed for the full trench depth and no soil is lost from behind or below.
- Damaged components come out of service until a competent person, and where required a registered professional engineer, says otherwise.
Daily inspection checklist
- Cylinders holding pressure, with no leaks or loose shores.
- Rails straight, not bent or cracked; pins and fittings intact.
- Spacing matches the tables for the current soil type and depth.
- No soil raveling between shores; add sheeting if it is.
- Ladder within 25 feet of lateral travel, inside the shored zone.
Compare hydraulic shoring with other systems in types of trench shoring.
Sources and official references
Last reviewed: October 25, 2026 · Free general education based on OSHA 29 CFR 1926 Subpart P. It does not replace the site-specific training and competent person your employer must provide, and it does not issue a certificate. Nothing you enter on this page is saved or sent.