What Access and Egress Has to Be in Place Before Anyone Enters

Why this matters

Every other protective element in a trench can be built after the fact. The box is set from grade, the slope is cut from grade, the spoil is pulled back from grade, the atmosphere is tested from grade. Egress is the only one the first person down has to use on the way down, which means it is the only one that must physically exist before anyone is exposed. If installing your means of egress requires somebody to be in the trench, the sequence is already wrong and the correction is not a better ladder, it is a different order of work.

The second thing this card is about is what the 25-foot rule is actually measuring, because it is not measuring the trench. It is measuring the walk.

The rule, and what it counts

29 CFR 1926.651(c)(2): a stairway, ladder, ramp or other safe means of egress shall be located in trench excavations 4 feet or more in depth so as to require no more than 25 feet of lateral travel.

Two scoping points that get lost. First, this clause is written for trench excavations. 1926.650(b) defines a trench as a narrow excavation, deeper than it is wide, with a bottom width not greater than 15 feet. A basement cut or a pit wider than that at the bottom is not a trench, the 25-foot number does not attach to it, and safe access there is normally a ramp under 1926.651(c)(1). Do not quote 25 feet as if it were universal to all excavations.

Second, "lateral travel" is travel, not trench length. It is the distance a person actually walks, along a path they can actually use, to reach the nearest way out. Anything that blocks the path shortens the effective spacing, and nothing in the trench announces that it has done so.

Deriving the count

For an unobstructed run, a ladder covers 25 feet in each direction, so an interior ladder serves a 50-foot segment and the two end ladders each cover 25 feet toward their ends. The minimum count is the run length divided by 50, rounded up. That relationship holds only where travel is possible in both directions along the whole length; every partition resets the arithmetic inside its own segment.

Worked example. 200 feet of open trench, 9 feet deep, shielded end to end with no end plates in the run.

• Minimum count: 200 / 50 = 4 ladders.
• Placed at 25, 75, 125 and 175 feet.

0    25         75         125        175  200
+-----L----------L----------L----------L-----+
 <-25-><---50----><---50----><---50----><-25->

Check the worst points rather than the ladders. A worker at 0 travels 25 feet. At 50, 25 feet to either neighbour. At 100, 25 feet. At 150, 25 feet. At 200, 25 feet. Every worst case lands exactly on the limit, which is the definition of a minimum count and also the reason most crews add one: at 25 feet of allowance there is no margin for a hose, a pump, a pipe length in the bottom or a person who is not walking well.

Two placements people reach for instead, and what each does:

• Ladders at 0, 100 and 200 (three ladders). A worker at 50 travels 50 feet. That is double the limit, and it fails on a trench that looks well equipped from the street.
• Ladders at 0, 50, 100, 150 and 200 (five ladders). Compliant, one more than the minimum, and the extra one buys back the margin the four-ladder layout does not have. If you are going to be wrong about ladder count, this is the direction to be wrong in.

What does not count as a means of egress

The rule's teeth are in the exclusions, and every one of these has been used on a real job by someone who believed they had egress.

• A spoil pile ramped down into the cut. Loose material at its angle of repose, not a designed ramp, and it puts a load at the edge that the protective system was not selected for.
• The excavator bucket. Not a personnel platform, never a ride. 1926.651(e) prohibits employees underneath loads handled by lifting or digging equipment, and the bucket is not an exception because someone is standing in it rather than under it.
• A shield's cross-braces. Climbing struts puts a person between the brace and the wall, and a brace is a compression member sized for soil load, not a rung.
• A ladder outside the shield. 1926.652(g)(1)(iii) requires employees to be protected from cave-in when entering and exiting the area the shield protects. If the walk from the ladder to the box crosses unprotected trench, the ladder is not egress from that box, and neither is a ladder standing in the void between the box and the wall.
• A ladder in a box that is being moved. 1926.652(g)(1)(iv) prohibits employees in shields while the shield is installed, removed or moved vertically, so the ladder inside the box you are about to reset serves nobody. The crew comes out first.
• A ladder that stops at grade. 1926.1053(b)(1), in Subpart X, requires the side rails to extend at least 3 feet above the upper landing surface, or, where that is not practicable, the ladder to be secured at the top with a grasping device provided. The last three feet of a climb out is where a person's hands run out of ladder.
• An unsecured ladder. A ladder that shifts under load at 9 feet of depth is a fall into the one place you cannot easily reach someone.
• "The far end is only forty feet." Distance is not a defence. The limit is 25 feet of travel, and it is a limit because the number is about seconds, not steps.

That last point is the one worth holding. The 25 feet is a bound on how long a person is still in the trench after they decide to leave it. A cave-in gives its warning in seconds where it gives one at all, and a 50-foot walk through a trench that is already moving is not a walk anyone completes.

What partitions a trench, and therefore resets the count

Each of these creates a segment that needs its own means of egress, because a person on one side of it cannot reach a ladder on the other:

• Shield end plates. The most common one by far, and it is invisible from the street.
• A brace or strut at knee height in a shoring run that a person cannot pass without climbing.
• Pipe, fittings or a bell hole in the bottom that blocks passage for the length of the shift.
• A gap of unprotected trench between two boxes. Travelling through it to reach a ladder is exposure, so that gap partitions the run rather than connecting it.
• A utility crossing the trench, supported under 1926.651(b)(4), sitting at a height a person cannot pass under or over.
• Standing water deep enough that the path is not walkable, which is separately a bar on entry under 1926.651(h)(1).

The practical rule that follows: count ladders per compartment, not per trench, and re-count every time the layout changes. A box pulled at lunch to set a fitting has re-partitioned the run, and the afternoon crew is working to a morning ladder plan.

Ramps and stairways, and the case for them

1926.651(c)(1) covers structural ramps. Ramps used solely by employees as a means of access or egress are designed by a competent person; ramps used for equipment access are designed by a competent person qualified in structural design, which is a higher bar and a deliberate one. Structural members are of uniform thickness, members are connected to prevent displacement, cleats are attached to the bottom of the runway or in a manner achieving equivalent strength, and a ramp used in place of steps gets cleats or surface treatment on top to prevent slipping.

Where a ramp or a stair tower beats a ladder is a judgement most crews never make explicitly. Four conditions push toward it: work lasting more than a shift or two in one place, crews larger than a couple of people, anything being carried in or out by hand, and the case nobody plans for, which is getting an injured person up. You cannot carry someone up a ladder. On a deep, long-duration cut, the egress that matters is the one a two-person carry can use, and that decision is made when the excavation is planned or it is not made at all.

How to verify

Do all of it from grade, before the first entry of the day, and re-do it after any change to the box layout.

1. Walk the run at grade and mark every partition you can see, then ask the crew about the ones you cannot - a pipe stack, a bell hole, a brace.
2. Count segments, not length. For each segment, take its length, divide by 50 and round up, and check the ends and the midpoint against 25 feet by pacing it at grade.
3. Confirm every ladder is inside the protected zone it serves, with the walk from its foot to the work entirely inside protection.
4. Check the 3 feet above the landing on each ladder, and check that each is secured against displacement, per 1926.1053.
5. Confirm the ladders went in before the first person, not after. This is a sequencing check on the plan, and the tell that it failed is a ladder set from inside the trench.
6. Ask how an unconscious person comes out of the deepest station. If the answer is a ladder, the answer is wrong, and the fix is a ramp, a stair tower or a planned rescue capability, decided now rather than during the event.

The failure mode this last check catches is the one that does not show up in any inspection: a trench that is fully compliant on ladder count, in which nobody has thought about extraction, so the first minutes of an injury are spent improvising a method instead of using one.

References

• 29 CFR 1926.651(c), access and egress, including structural ramp design at (c)(1) and the 25-foot lateral travel limit for trench excavations 4 feet or more deep at (c)(2)
• 29 CFR 1926.650(b), definitions, including the definition of a trench that scopes the 25-foot rule
• 29 CFR 1926.652(g)(1), additional requirements for shield systems, including protection when entering and exiting and the prohibition on occupied shields being moved
• 29 CFR 1926.1053, ladders, Subpart X, including the 3-foot extension above the upper landing surface at (b)(1)
• See related: How to Run a Daily Excavation Inspection That Would Hold Up; universal-why-shoring-and-shielding-are-not-the-same-decision