# SWP - Trench Rescue > Fire Service Safety Management System, version 0.3.3 (2026-10-25). The Human Factor. Document FSSMS-SWP-20. > > Canonical: https://thehumanfactor.ca/library/fire-service-safety/swp-trench-rescue > > Licence: CC BY-NC-SA 4.0 with the Adopting Agency Grant (https://creativecommons.org/licenses/by-nc-sa/4.0/) > > General information only, not legal, medical or other professional advice. Verify every requirement against the current official text of the law, standards and manufacturer instructions that apply to you. Obtain your own legal review and consult your joint health and safety committee before adopting anything. You adopt, adapt, implement and rely on this material entirely at your own risk and on your own responsibility. Full terms: Terms of Use, thehumanfactor.ca. > **Warning: Adoption without implementation increases legal exposure** > > Adopting this procedure without the training, equipment, supervision, verification and resources to carry it out as written increases municipal and command liability in a regulatory investigation or a fatality inquiry. See [00a Copyright, Licence and Legal Notices](https://thehumanfactor.ca/library/fire-service-safety/copyright-licence-and-legal-notices). > **Speak up: Speak up** > > Anyone can stop this task if it looks wrong. Say the hazard, then the action: “Stop, everybody off the lip, the wall is moving.” The rescue group supervisor acknowledges, holds, and reviews it later for learning. Debrief question for this task: what did the victim and the people on site ask us to do, and what did we do first? ## 1. Task and when this applies Rescue of a person trapped or buried in a trench or excavation, at the department’s declared level ([Trench and Structural Collapse Rescue Program](https://thehumanfactor.ca/library/fire-service-safety/trench-and-structural-collapse-rescue-program) section 5.1). Awareness-level crews use steps 1 to 6 and hold the scene; operations-level crews continue through step 15 in straight trenches with commercially manufactured protective systems; technician-level work and every engineer trigger follow the program. There is no rescue exception to the rule that an unprotected trench deeper than the depth the applicable law sets is not entered ([J18 Excavation and Trench](https://thehumanfactor.ca/library/fire-service-safety/j18-excavation-and-trench)). ## 2. Hazards - Secondary collapse of the walls, the spoil pile or the adjacent ground, set off by rescue activity, vibration, water, frost or load; a cubic metre of soil can weigh as much as a small car. - Entrapment of rescuers who enter to dig out a visible victim before the trench is protected, the recurring pattern in trench fatality investigations. - Hazardous atmospheres: sewer gas, fuel vapour, oxygen-displacing gases, engine exhaust pooling in the trench. - Live utilities in and beside the trench: gas, electrical, water under pressure, telecommunications. - Water accumulation; undermined walls; previously disturbed soil; frost and thaw. - Falls into the trench; struck by shoring, tools and equipment lowered or dropped. - Crush and strain injuries handling panels and shores; air supply and pneumatic hazards. ## 3. Controls in hierarchy order 1. **Elimination.** Nobody enters an unprotected trench; the victim is reached by making the trench safe from outside first. Where the victim is clearly deceased, the operation becomes a recovery with no acceptance of risk to members. 2. **Substitution.** Reach, voice contact and a dropped airway shield or air supply before entry; vacuum and air tools instead of hand digging near the victim. 3. **Engineering.** Commercially manufactured panels and pneumatic or hydraulic shores installed to the manufacturer’s tabulated data, or an engineer’s design; ground pads; ladders in the protected zone; ventilation; dewatering; isolation of utilities (the applicable excavation rules; [J18 Excavation and Trench](https://thehumanfactor.ca/library/fire-service-safety/j18-excavation-and-trench)). 4. **Administrative.** This procedure; the exclusion distance for vibration; the spoil distance; the secondary collapse watch; the engineer triggers; the size-up checklist; a safety officer and accountability at the lip [(NFPA 1550, 2024)](https://thehumanfactor.ca/library/fire-service-safety/swp-trench-rescue#ref-nfpa-1550). 5. **PPE.** Technical rescue helmet, gloves and eye protection [(NFPA 1950, 2025)](https://thehumanfactor.ca/library/fire-service-safety/swp-trench-rescue#ref-nfpa-1950); respiratory protection as the atmosphere requires; rescue harness and a lifeline on every member in the trench; hearing protection with air tools. ## 4. Required PPE and equipment Trench rescue cache: panels, strongbacks, pneumatic or hydraulic shores with air supply and tabulated data, timber, wedges, ground pads, cribbing; two ladders; multi-gas detector with pump; ventilation fan and ducting; dewatering pump; vacuum or air-knife tools, hand tools; rescue harnesses, lifelines and the logged rope kit for a vertical lift; patient packaging (basket and backboard); medical equipment including airway protection for a partly buried victim; building and hazard marking; lighting; barrier tape and scene signage. ## 5. Minimum staffing and competencies Awareness: the first-arriving company with its officer. Operations: a rescue group supervisor, a safety officer, a secondary collapse watch, a panel and shoring team of at least four, an entry team of two with a back-up of two, an air and equipment custodian, and medical; every rescue team member trained to the trench rescue job performance requirements at the declared level [(NFPA 1006, 2021, ch. 12)](https://thehumanfactor.ca/library/fire-service-safety/swp-trench-rescue#ref-nfpa-1006) with the annual evolution in real soil on record. The on-call engineer is contacted at any trigger in step 8. ## 6. Step-by-step procedure 1. **Hold the scene.** The first officer takes command, gets everyone out of the trench and off the lip (including the contractor’s crew and family), and keeps them back. **Decision point: is anyone trying to dig the victim out? Stop them now, and explain why: the next collapse will bury the diggers.** 2. **Stop the vibration.** Shut down every engine, compressor and machine within the department’s exclusion distance, commonly 15 m or more; divert traffic; position apparatus back on firm ground with one access route. 3. **Size up from the lip, from outside the wall-height distance.** Victims (number, position, buried depth, conscious, airway clear), trench dimensions and configuration, soil (type, layered, wet, previously disturbed, frost), water, utilities, spoil pile location, adjacent structures and poles, weather. Complete the size-up checklist ([Trench and Structural Collapse Rescue Program](https://thehumanfactor.ca/library/fire-service-safety/trench-and-structural-collapse-rescue-program) section 17.1). 4. **Utilities.** Assume every line live and charged; call the utilities and the contractor to isolate; no work over an unisolated gas line. 5. **Atmosphere.** Test at the lip and at depth with the pump and tubing before anyone approaches the edge to work; set ventilation; continuous monitoring from here on. **Decision point: oxygen in range, flammables below the department’s action level (10 percent LEL), contaminants below limits? If not, ventilate and retest before any work at the lip.** 6. **Talk to the victim.** Reassure, keep them still, assess airway and breathing from the lip; where the victim is partly buried, protect the airway from further spoil with a shield or a helmet passed down by pole; begin oxygen by extension if it can be delivered without entry. 7. **Spoil and loads.** Move or cut back the spoil pile and every load to the distance from the lip the applicable excavation rules set ([J18 Excavation and Trench](https://thehumanfactor.ca/library/fire-service-safety/j18-excavation-and-trench)); lay ground pads around the working edge; nothing is placed within the wall height of an unprotected wall. 8. **Engineer check.** Depth beyond the depth at which your jurisdiction requires an engineered design (3 m to 6 m in most jurisdictions, and some require an engineer for all shoring; [J18 Excavation and Trench](https://thehumanfactor.ca/library/fire-service-safety/j18-excavation-and-trench)), intersecting trenches, adjacent structures or utilities whose support is affected, previously disturbed soil, sloping steeper than your jurisdiction’s rule, or non-standard shoring: call {{Structural Engineer (on call)}} through dispatch and record the time. **Decision point: is any trigger present? If yes, no entry until the engineer’s advice is received and recorded, however long that takes.** 9. **Select the protective system** from the manufacturer’s tabulated data for the soil, depth and configuration; brief the panel team on the sequence; assign the secondary collapse watch, who watches the walls, the spoil and the adjacent ground and has the authority to order everyone off. 10. **Install from outside, top down.** Panels placed from the lip with rope and strongbacks; the first shores set from above with extension tools; the trench is never entered to place the first shore; shores pressurized to the manufacturer’s tables and locked; supplemental shoring added where the victim’s position needs it; the system checked by a second trained person before anyone enters. 11. **Ladders.** A ladder in the protected zone extending above the top within the distance the applicable excavation rules set of every member in the trench ([J18 Excavation and Trench](https://thehumanfactor.ca/library/fire-service-safety/j18-excavation-and-trench)); a second ladder where the work area is long. 12. **Enter and dig.** The entry team of two, on lifelines, inside the protected zone only; dig by hand and with vacuum or air tools around the victim; no mechanical digging within reach of the victim; protect the victim’s airway and body; medical care in the trench by a protected member; keep the back-up team dressed at the lip and the count current. **Decision point: has the victim’s condition or the trench changed such that continuing exposes members for no survivable outcome? The incident commander decides and records the recovery decision and its time.** 13. **Package** for a vertical lift (basket or backboard with the rope system rigged under [SWP - Rope Rescue Systems Rigging and Inspection](https://thehumanfactor.ca/library/fire-service-safety/swp-rope-rescue-systems-rigging-and-inspection)); the whistle test before loading; lift with the shore system undisturbed. 14. **De-shore bottom up** only when every member is out; shores depressurized in reverse order from the lip; panels recovered with rope; nobody re-enters to retrieve equipment. 15. **Close.** Count everyone; rehab; notify the regulator and the owner as a workplace incident where required; inspect and log every shore, panel and rope used; AAR scheduled. > **Warning: Stop-work triggers** > > Any wall movement, cracking, bulging or water seepage; the secondary collapse watch calls it; a detector alarm; a utility that cannot be confirmed isolated; vibration that cannot be stopped; a shore that will not hold pressure; an engineer trigger without the engineer’s advice; a member inside the wall-height distance of an unprotected wall; anyone, of any rank, calling it. ## 7. Emergency and contingency - **Secondary collapse with members in the trench:** everyone else off the lip; mayday per [SWP - Mayday](https://thehumanfactor.ca/library/fire-service-safety/swp-mayday); the back-up team works only inside the protected zone and only after the collapse watch confirms the system held; the engineer is called if not already on the way; medical. - **Member buried:** do not dig with members in an unprotected area; extend the protected zone first; airway first when reached. - **Atmosphere deteriorates:** everyone out by the ladders; ventilate; retest; re-entry only below the action levels. - **Shore or air supply failure:** everyone out; depressurize nothing with members inside; replace or supplement from outside. ## 8. Documentation and reporting The size-up checklist, the shoring selection (tables used), the engineer’s advice, the atmospheric readings, the entry and recovery decisions and the times are the incident record. Every trench response gets a Tier 1 AAR; any entry into an unprotected trench, any secondary collapse with members inside the zone, any shoring failure and any near miss with potential for death goes to Tier 2 ([Incident Investigation and Learning Program](https://thehumanfactor.ca/library/fire-service-safety/incident-investigation-and-learning-program)). Equipment used is logged ([Trench and Structural Collapse Rescue Program](https://thehumanfactor.ca/library/fire-service-safety/trench-and-structural-collapse-rescue-program) section 17.2). ## 9. Training and review Awareness for every member on the three-year refresher; operations and technician to the job performance requirements with an annual evolution in real soil and quarterly drills; shoring custodians assessed annually. The Technical Rescue Program Improvement Team reviews this procedure every three years, after every event in section 8, and on any change in the cache, the engineer arrangement or the applicable excavation rules; the JOHSC is consulted. ## 10. Related [Trench and Structural Collapse Rescue Program](https://thehumanfactor.ca/library/fire-service-safety/trench-and-structural-collapse-rescue-program); [Confined Space Program](https://thehumanfactor.ca/library/fire-service-safety/confined-space-program) (atmosphere); [SWP - Confined Space Entry and Rescue](https://thehumanfactor.ca/library/fire-service-safety/swp-confined-space-entry-and-rescue); [SWP - Rope Rescue Systems Rigging and Inspection](https://thehumanfactor.ca/library/fire-service-safety/swp-rope-rescue-systems-rigging-and-inspection); [SWP - Mayday](https://thehumanfactor.ca/library/fire-service-safety/swp-mayday); [Checklist - Confined Space, Trench and Rope Rescue](https://thehumanfactor.ca/library/fire-service-safety/checklist-confined-space-trench-and-rope-rescue). ## Jurisdiction requirements This chapter relies on the following legal requirements, which differ by province and territory. Check your jurisdiction’s section on each topic page before adopting it. | Topic | What to check in your jurisdiction | Page | |:---|:---|:---| | Excavation and Trench | The depth that triggers protection, the sloping, shoring and engineer rules, ladder and spoil distances, atmospheric testing, and any firefighter exemption | [J18 Excavation and Trench](https://thehumanfactor.ca/library/fire-service-safety/j18-excavation-and-trench) | ## References National Fire Protection Association. (2021). *NFPA 1006, Standard for technical rescue personnel professional qualifications*. National Fire Protection Association. (2024). *NFPA 1550, Standard for emergency responder health and safety* (consolidates NFPA 1500, 1521 and 1561). National Fire Protection Association. (2025). *NFPA 1950, Standard on personal protective equipment for technical rescue incidents, emergency medical operations, and wildland and urban interface firefighting* (consolidates NFPA 1951, 1977 and 1999).