Trench Cave-Ins: Why Trench Walls Fail
What a cave-in is and why it kills, what makes trench walls fail, how time, vibration and frozen ground add to the risk, and what your dig can undermine nearby.
Getting Locates Before You Dig: Calling 811
Requesting locates through 811 before you dig, private lines 811 may not mark, pipelines in the dig area, what to have on site, when tickets expire, and your own ticket and emergencies under state 811 law.
Reading Locate Marks: The Color Code and Offsets
How to read locate marks: the eight-color code, white-lining your dig, offset marks, protecting the marks on site, and asking 811 for a re-mark when a mark is gone.
Finding and Exposing Buried Lines
Finding buried lines with potholes, digging by hand or vacuum excavation inside the tolerance zone (18 inches each side), keeping machines 1 foot clear once found, and what to do about lines or objects nobody marked.
Exposed Lines and Utility Strikes
What to do before you uncover a line, how to protect exposed lines, what to do if you hit a gas, steam, water or sewer line, and reporting any damage, even a scratch, to the owner and 811.
Trench Soil Types: Stable Rock, Type A, B and C
Who classifies the soil and how, the four soil types from Stable Rock to Type C, what to do when it isn't clear-cut, and reclassifying the soil when conditions change.
Choosing Trench Protection: Sloping, Shoring and Trench Boxes
When a trench 5 feet deep or more needs a protective system, the steepest slopes and benching for each soil type, shoring and trench boxes, and when a registered professional engineer must design the protection.
Using Shoring and Trench Boxes Safely
Setting up and moving a trench box, staying inside the protection, looking after shoring, and putting it in and taking it out.
Getting In and Out of a Trench: Ladders and Ramps
A safe way out of any trench 4 feet deep or more within 25 feet of travel, staying protected getting in and out of a trench box, ladders, ramps and lighting.
Daily Trench Checks and Warning Signs
Daily inspections by a competent person, the warning signs of a cave-in, what to do when you see one, water in the trench, and live sewers and plugs.
Bad Air in Trenches: Gases, Engines and Air Testing
Where bad air in a trench comes from, what to do if the air is bad, engines running in or near the trench, and testing the air before anyone goes in.
Trench Edges, Machines and the Public
Keeping spoil and equipment 2 feet back from the edge, falls and falling material, machines near the walls, loads and reversing, and keeping the public out.
Trench Emergencies and Rescue
Having a written emergency plan, never working in a trench alone, and what to do if a worker is buried or collapses in bad air, so rescuers don't become second victims.
General information only, not legal advice. Always follow federal and state regulations, your employer's procedures and the instructions of a competent person on your site. Narration is AI-generated (the Dashpot narrator voice); every script is checked against the sources listed above before it is voiced.