Snohomish County Fire Chiefs Training Division

1. Snohomish County Fire ChiefsTraining Division Operations Level Trench Rescue

2. Standard Operating Guideline for Trench Operations • A Trench shall be defined as a narrow excavation, in which the depth is greater than its width, but the width measured at the bottom is not greater than 15 feet. • An Excavation shall be defined as any man made cut, cavity, trench or depression in an earth surface formed by the earth’s removal. In practical terms, when a hole is more than 15 feet wide at its base it is called an excavation; or an excavation is wider than it is deep. • Any incident in which a person is trapped, buried or experiencing a medical emergency in a trench or excavation shall require the response of the Technical Rescue Team.

3. Standard Operating Guidelinefor Trench Operations • No personnel shall be allowed to enter an unprotected trench or excavation to perform patient care or rescue operations. All trenches shall be made “safe and protected”, using approved methods and materials, prior to entry by rescue personnel. • Only those personnel with Operations and/or Technician level training shall enter a “safe and protected” trench or excavation. • The general duties of Operations level personnel will include size-up and assessment of the site, request for additional manpower and ensuring the safety of the site and personnel.

4. Standard Operating Guidelinefor Trench Operations • Operations level personnel shall employ the following guidelines when faced with a trench or excavation rescue incident: • Request a technical rescue response from dispatch. • Initiate the Incident Management System (IMS)- including the establishment of a staging area for incoming units and personnel, as well as the implementation of the passport accountability system. • Isolate the scene and deny entry to prevent further danger to victim(s), personnel and bystanders • Park all vehicles at least 100’ away. Detour or stop all traffic within 300’ of the site.

5. Standard Operating Guidelinefor Trench Operations • Secure any and all machinery operating on site and remove keys to prevent accidental starting. • Establish a “hot zone” of at least 75’ around the perimeter of the trench site, removing all civilians and untrained rescuers from this area. • Gather information: • Rescue –vs- Recovery • Cause of accident • What function was the victim(s) performing in the trench • Number of victims • Specific victim information

6. Standard Operating Guidelinefor Trench Operations • Location of victim(s) in trench • Type of trench • Straight • L-shaped • T-shaped • X-shaped • Dimensions of trench • Length • Width • Depth • On site hazards • Disrupted utilities • Flowing water • Secondary collapse hazard • Hazardous materials • Heavy equipment or machinery

7. Standard Operating Guideline for Trench Operations • Advise dispatch and incoming units of updated, detailed information. • Place a ladder at the end of the trench nearest to the victim to allow for self-rescue. (This also enables the rescuer to self-rescue incase he/she accidentally falls in.) • Ventilate the trench with an electric powered, positive pressure fan. • Provide a helmet and eye protection to the victim. • Provide a shovel to the victim so they may attempt to dig themselves out. • Begin clearing a 2’ area around the lip of the trench in which to work from; moving spoil pile back from edge at least 2’.

8. Standard Operating Guideline for Trench Operations • Place ground pads around the lip of the trench to disperse weight. • Support and stabilize any unbroken utilities that are within your training to handle. • Assist the Technical Rescue Team as directed, staying within the scope of Operations level training. • Provide medical care to the victim(s) as soon as possible, from a “safe and protected” location. • Keep all unnecessary communications to a minimum during rescue operations.

9. Standard Operating Guideline for Trench Operations Please Note: Sheeting, shoring and disentanglement operations shall be conducted under the direction of a Rescue Technician. Operations level personnel may enter the trench, after it is “safe and protected”, to assist the Rescue Technicians. Operations level personnel shall only assist, under the direction of a Trench Rescue Technician, in construction of trench shoring systems.

10. Suggested Scene Management

11. Trench Anatomy

12. Types of Collapse

13. Air Shores • Positive Lock • No chance of creep back • Can be applied manually or pneumatically • Tested • Crush strength of 61,000 lb. up to 4 feet, 49,000 lb. up to 8 feet and 42,000 lb up to 12 feet using two locking pins. • Recommended pressure 200 psi for trench rescue • It is not necessary to insert the second pin for trench rescue

14. Air Shores • Airshore Installation • Determine proper size and support configuration needed. (flat base or swivel) • Ensure pins are out of piston and lock collar. • Place the airshore in the desired position. • If operating manually- extend the head until the plates contact the strongbacks and place pin in the closest piston hole , turn collar up using T-handle until it snugs up against the pin. Tighten T-handles.

15. Air Shores • If operating pneumatically- connect regulator hose to air supply. Slowly turn pressure on. Check regulator to ensure adequate pressure and that regulator is set properly (200 psi). Pressurize strut until heads are in contact with strongbacks. Place pin in closest piston hole to collar. Turn collar up using T-handles until snug up against the pin. Tighten the T-handles • Secure bases with nails • Disconnect the air supply

16. Air Shores • Proper firing order for Airshores: • Top • Middle • Bottom

17. A Shored Trench

18. Some Key Points to RememberDuring trench Operations • Trenches 4’ or greater in depth must be shored prior to entry. • A trench can contain many hazards such as: • Low O2 • Water or drowning conditions • Heavy machinery • Operating equipment • Broken or damaged utilities • Trauma potential • PPE Considerations • Helmet • Gloves • Steel toed boots • Jumpsuits or work clothes are sufficient • Personnel entering trench will also be required to don a Class III harness

19. The End

20. Technical Rescue Responsefor Trench Rescue • Unconfirmed or calls with limited information may be a dispatched as a first or second alarm depending on how the jurisdiction has it’s FRL’s set up. • Confirmed trench rescue or will require a third alarm or need to be balanced to a third alarm to get the proper number of Rescue Technicians to the scene • On second and third alarms for trench the closet HazMat unit will also be dispatched for air monitoring

21. Technical RTeescue Responsefor Snohomsih County