Trench Shoring & Protective System Selector
OSHA 1926.652 decision-tree for excavation protection by soil type and depth
OSHA requires protective systems for all trenches 5 feet deep or greater, and recommends them for shallower trenches where conditions warrant. The standard (29 CFR 1926.652) gives employers four options: sloping, benching, shoring, and shielding. Which options are available depends on the soil classification and trench depth.
Soil classification is the critical first step. OSHA defines three soil types: Type A (most stable, such as caliche, hardpan, or stiff clay), Type B (medium stability, such as angular gravel or disturbed Type A), and Type C (least stable, such as granular sand or submerged soil). Each soil type has different maximum allowable slopes, benching configurations, and shoring load requirements. Getting the soil classification wrong can be fatal.
This tool screens the OSHA depth and soil-type decision points. Enter your trench dimensions, the soil classification your competent person determined on site, and site conditions such as water seepage. The calculator lists which protective-system families the standard makes available, the Appendix B slope geometry, and simplified timber prompts, with the source limits stated on every output.
Calculate OSHA slope angles by soil type
Trench Sloping Calculator →Estimate excavator production rates for the dig
Excavator Production Calculator →Check soil bearing capacity at the trench bottom
Soil Bearing Capacity Calculator →How It Works
-
Select the Soil Type
Choose the OSHA soil classification determined by your competent person on site. The tool does not classify soil; it applies simplified Appendix A downgrade prompts to the type you select.
-
Enter Trench Dimensions
Enter trench depth, width, length, spoil-pile distance, and site conditions (water seepage, vibration, prior disturbance, adjacent loads). Water seepage reclassifies the soil to Type C.
-
Review Listed Options
The tool lists which protective-system families (sloping, benching, timber shoring, hydraulic shoring, shielding) the standard makes available for the entered soil type and depth, with geometry shown for the sloping option.
-
Verify and Document
Export the screening report as a planning aid. The competent person and, where required, a registered professional engineer make the actual protective-system decision against the official OSHA tables and manufacturer tabulated data.
Features & Capabilities
Depth Decision Prompts
OSHA 1926.652 depth thresholds: protection at 5 ft or less per competent-person judgment, tabulated options for 5-20 ft, and PE design required above 20 ft.
Slope Angle Tables
Maximum allowable slopes per Appendix B: Type A (3/4H:1V, 53 degrees), Type B (1H:1V, 45 degrees), Type C (1-1/2H:1V, 34 degrees).
Timber Shoring Prompts
Simplified timber member-size prompts derived from OSHA Appendix C for 5-20 ft trenches, flagged in-app as pending verification against the printed tables.
Shield & Hydraulic Pointers
Trench shield and aluminum hydraulic shoring options listed with manufacturer tabulated-data reminders; the tool does not size cylinders, walers, or shield pressure ratings.
Soil Downgrade Rules
Water seepage reclassifies the soil to Type C; prior disturbance, vibration, or adjacent loads downgrade Type A to Type B per simplified Appendix A prompts. Benching is disallowed for Type C.
Safety Checklist
Egress ladder counts, spoil setback, competent-person inspection, atmosphere testing, crossing, and water-control reminders with OSHA section references.
References
- OSHA 29 CFR 1926 Subpart P - Excavations (1926.650-652 and Appendices A-C)
- Maximum allowable slopes: Type A = 53 degrees (3/4H:1V), Type B = 45 degrees (1H:1V), Type C = 34 degrees (1-1/2H:1V)
- Tabulated screening prompts cover trenches from 5 to 20 feet deep; deeper trenches require PE design
- Timber member-size prompts are a simplified Appendix C extract pending line-by-line reconciliation; confirm against the printed tables
Frequently Asked Questions
Learn More
Trench Safety: OSHA Protective System Requirements
OSHA 1926.652 trench protection requirements explained. Soil classification, sloping angles, shoring options, and trench box selection by depth and soil type.
Related Tools
Lockout/Tagout Permit Manager
Create OSHA-compliant LOTO permits for equipment energy isolation. Track electrical, pneumatic, hydraulic, and thermal energy sources with lock assignments and zero-energy verification.
Scaffold Load & Tie Calculator
OSHA 1926.451 scaffold loading calculator. Determine platform capacity, leg loads, mudsill sizing, and tie spacing for light, medium, and heavy-duty scaffolding.
Fire Sprinkler Hydraulic Calculator
NFPA 13 sprinkler hydraulic calculator. Compute flow using K-factor, Hazen-Williams friction loss in piping, and total system demand at the riser with hose stream allowance.