Struck-by and caught-in-between hazards can be reduced by separating workers from moving equipment, falling objects, unstable materials, rotating parts, trenches, and pinch points. Controls should be planned before work begins and reinforced during daily supervision.
Key takeaways for quick planning
- These hazards are not limited to heavy civil projects; they appear on building, demolition, utility, and maintenance jobs.
- The hierarchy of controls should guide planning before relying on reminders alone.
- Good protection combines layout, equipment condition, communication, exclusion zones, and competent supervision.
What these hazards include
A struck-by hazard involves contact with a moving, flying, falling, swinging, or rolling object. A caught-in-between hazard involves being crushed, squeezed, pinned, buried, or pulled into equipment or materials. OSHA construction resources on struck-by hazards describe common equipment and vehicle exposure scenarios.
The most serious cases often involve trucks, loaders, excavators, cranes, suspended loads, stacked materials, trench cave-ins, unguarded machinery, and workers standing between equipment and fixed objects.
Build separation into the job plan
The safest plan reduces the need for people and moving equipment to share the same space. Use barricades, spotter rules, traffic flow, equipment swing-radius control, material storage plans, hard barricades near edges, and clearly communicated exclusion zones. PPE helps, but it should not be the only control.
The Center for Construction Research and Training offers resources on struck-by hazards that can support toolbox talks and planning. Teams should adapt any training to the specific site, task, and equipment in use.
Hazard-control comparison
| Risk | Planning control | Field signal to stop |
|---|---|---|
| Vehicle movement | Traffic plan and separated walkways | Worker enters blind spot or route changes |
| Falling materials | Stacking limits and overhead exclusion zones | Material leans, shifts, or is lifted over people |
| Excavation collapse | Protective system and competent inspection | Water, cracking, vibration, or spoil too close |
| Attachments | Inspection and positive engagement checks | Unconfirmed coupler lock or damaged connection |
Caught-in-between risks during excavation and equipment work
Trenching is a major caught-in-between concern. OSHA notes that excavation and trenching are among the most hazardous construction operations, and its trenching and excavation safety publication explains protective systems and planning considerations. Do not treat a shallow or short-duration excavation as automatically safe. Soil, water, vibration, surcharge loads, and access all matter.
Equipment attachments also deserve attention. NIOSH has highlighted quick coupler attachment failures as a struck-by risk; its excavator quick coupler fact sheet reinforces the need for inspection, training, and correct connection procedures. This connects directly with equipment planning for mini excavator attachments.
Field checklist for supervisors
- Identify moving equipment paths and pedestrian routes before work starts.
- Keep workers outside swing radius and blind spots unless controlled procedures are in place.
- Secure materials against rolling, shifting, or falling.
- Inspect guards, backup alarms, mirrors, cameras, couplers, rigging, and brakes as applicable.
- Use trench protective systems and safe access where required.
- Stop work when changing conditions make the original plan unreliable.
Pre-task questions that reveal hidden energy
Before work starts, ask what can move, swing, roll, fall, collapse, pressurize, rotate, or shift. Then ask where a worker could be standing if that energy is released. This simple conversation often reveals blind spots that a generic checklist misses.
The crew should also discuss what changes would stop the job: weather, traffic, failed alarms, missing spotters, unstable soil, damaged rigging, unclear hand signals, or unplanned deliveries. Stop-work triggers are easier to respect when they are named in advance.
Training that fits the actual task
Toolbox talks should use the day’s equipment, layout, and materials. A talk about struck-by hazards is stronger when it points to the actual swing radius, haul route, stacked material, or overhead work happening that morning.
Supervisors should watch for drift during the shift. Barricades get moved, trucks arrive early, attachments change, and workers take shortcuts when schedule pressure rises. Safety planning is not a morning-only activity.
Using the hierarchy of controls
Elimination and substitution may mean changing the method so workers do not enter the danger zone. Engineering controls may include barriers, trench boxes, guards, and physical separation. Administrative controls include traffic plans, spotters, signals, sequencing, and permits. PPE is the last layer, not the full plan.
This hierarchy keeps teams from relying only on reminders. A warning to stay alert is weaker than a layout that keeps people away from moving equipment. A verbal caution is weaker than a guard that prevents contact with rotating parts.
Near misses deserve real review
A near miss should be treated as useful information, not as proof that the crew got lucky. If a load swung over a worker, a truck backed without a spotter, or soil sloughed into a trench, the plan needs correction before work continues.
Reviews should focus on conditions and controls, not blame alone. Ask what made the unsafe position possible and what barrier, sequence, or communication change would make it less likely next time.
Coordination with deliveries and visitors
Many struck-by exposures come from people who are not part of the regular crew: delivery drivers, inspectors, tenants, utility workers, or visitors. The site plan should explain where they enter, park, unload, wait, and communicate with supervision.
Do not assume visitors understand equipment blind spots or exclusion zones. A brief orientation, clear barriers, and controlled delivery windows can reduce confusion around moving equipment and suspended or stacked materials.
Equipment inspection as prevention
Inspection is not paperwork when it catches a failing alarm, damaged guard, worn tire, leaking hydraulic line, cracked attachment, or unreliable brake. Equipment condition directly affects struck-by and caught-in-between exposure.
Inspection findings should lead to action. If a machine is unsafe, tagging it out or removing it from service may be necessary. Production pressure should not override a known equipment defect.
A practical crew reminder
The clearest warning sign is often a worker standing where equipment, soil, materials, or suspended loads could move. Supervisors should correct that position immediately and then ask why the worker needed to be there. The answer may reveal a layout or sequencing problem, such as poor access, unclear staging, missing tools, or pressure to work inside a hazardous zone.
The safety habit that actually sticks
The most useful safety conversations happen before the task changes, not after a near miss. Ask what can move, fall, roll, swing, collapse, or pinch, then place people outside that energy path. This article is educational and does not replace OSHA compliance, site-specific safety planning, competent-person duties, engineering, or legal advice.
