Manufacturer Tabulated Data

Trench boxes, hydraulic shores and similar systems are designed and tested by their makers. The maker's tabulated data tells you the depth, soil type and conditions the system can handle. If you use it outside those limits, it may not protect you.

• Excavation
• Competent Persons
• Contractors

What it is

Tabulated data is a set of charts, tables and drawings from the manufacturer, approved by a registered professional engineer. It shows how the product should be used and its limits. OSHA lets employers use it as one of the ways to select a protective system (1926.652(c)(2)).

What it contains

• Identification of the system, model and parts covered.
• Maximum depth of excavation it is approved for.
• Soil types (A, B, C) it can be used in. See Soil Classification.
• Spacing, installation and removal instructions for struts, rails and spreaders.
• Limits on loads from surface surcharge, adjacent structures or vibrations.
• The signature or seal of the engineer who approved the data.

Rules to follow

• Keep a copy on site while the system is in use (1926.652(c)(2)). It must be available to the competent person and inspectors.
• Use the system only within its limits. Match the data to the actual soil, depth, width and conditions.
• Install, use and remove it exactly as the data and instructions say.
• Have a competent person inspect daily and after any change. See Competent Person Inspections.

• Do not modify the system. Modifying, welding or cutting a box or shore changes the design and needs the manufacturer's or an engineer's approval.
• Do not stack or combine systems unless the data allows it.
• Do not use a system with damaged or missing parts.

When an engineer is needed

• The excavation is deeper than the data allows.
• The conditions do not match the data, for example unusually wet, layered or disturbed soil, heavy loads nearby or vibration.
• OSHA requires design by a registered professional engineer for protective systems for excavations deeper than 20 feet. See Deep Excavations.

Last updated: October 8, 2026