1. Trench for the First Responder
Chris Bednarek
Chicago Heights Fire Department

2. Orientation
Extension of the Trench Rescue material in the Technical Rescue Awareness class.
You will learn additional information about working safely around a trench rescue scene prior to the arrival of qualified trench rescue personnel.

3. Orientation
This class does not qualify you for OSFM certification, nor does is qualify you for entry at a trench rescue operation.
This information is intended to give the first-in company an idea of what to do and how to go about it safely.

4. Terms to Know
Angle of Repose – the greatest angle above the horizontal plane at which loose dirt will lie without sliding.
Back Fill – the refilling of a trench, or the material used to refill a trench, or to fill a void between two surfaces.
Spoil Pile – the material excavated from the trench.

5. More Terms to Know Fin Form – ¾”, 14-ply, arctic white birch.
Strong Back – a 2 x 10 or 2 x 12 attached to fin form to create a panel for shoring the wall of a trench.
Struts – the horizontal bracing between the trench walls.
Uprights – vertical supports, usually 2 x 8’s, the depth of the trench.
Ground Pads – 4x8 or 2x8 sheets of plywood used to disperse weight around the edge of the trench.

6. Where do we see trenches?
Commonly seen occupied and unprotected
Public works routinely work in trenches.
Pipeline & cable installation.
Areas of new construction (water, sewer)

7. Fin-form & strong backs
Air-Shore strut
Paratech strut
Back fill (wood & dirt)
Ground pads

8. Use of multiple types of shores
Fin-form & strong backs
Ground pads
Whalers
Escape ladders

9. OSHA
Defines a trench as an excavation that is deeper than it is wide and is no more than 15’ wide.
Has regulations governing operations in trenches 5’ deep or deeper.
Regulations apply to rescues.
Provides guidelines for trenches up to 15’ wide and 20’ deep. Custom engineering is required by a Registered Professional Engineer beyond those limits.

10. 60 to 65% OF ALL FATALITIES ARE THE WOULD-BE RESCUER
Lack of knowledge
Lack of training
Compassion for the victim

11. Trenches are Dangerous
Once earth is disturbed, pressure begins to act on the trench walls.
Sooner or later all trenches cave in.
There is no way to predict when a trench will fail.

12. Note the deterioration to the left corner

13. Vibration Hazards
All heavy equipment should be turned off and secured (take the keys and block the tires).
All sources of vibration should be eliminated for 300’ in every direction. This includes roadways and railways.

14. Backhoes Backhoe operators will insist they can dig the victim out.
OSHA statistics are riddled with cases of disembowelment and decapitation.
Backhoe operators cannot tell the difference between a rock and a body.
Weight of the backhoe adds to instability of trench walls.
Vibration likely to speed up secondary collapse

15. Atmospheric Hazards
The victim may be the result of bad air in the trench and have no actual trauma.
Air should be monitored every 15 minutes for O2, CO, H2S and combustibles.
Rescuers can fall victim to the same bad air if it is not checked regularly.
O2 permissible exposure limits: 19.5%-23.5%.
Methane Gas Flammable Limits: 5.0%-15.0%.

16. Public Utilities as a Hazard
Many trenches are dug for utility maintenance or installation.
Utility cables and pipes can add to trench instability.
Electrical utilities can pose a threat to both the victim and the rescuer.
Broken sewer or water lines may fill the trench, causing a drowning potential for the victim.

17. CONTACT WITH UTILITIES CAN BE DANGEROUS & CAUSE DISRUPTION TO SERVICE
Critical communications
CONTACT WITH UTILITIES CAN BE DANGEROUS & CAUSE DISRUPTION TO SERVICE
Fire protection
Power grid
Traffic flow
GAS SERVICE
ROADWAY UNDERMINING

18. Heavy equipment can fall into the trench trapping workers
Workers can be struck by operating heavy equipment

19. Digging their own grave…

20. Seattle, WA
8/8/2000
Worker killed
Rescuers using camera to locate victim’s body

21. Lebanon, MO
1989
Hit 10” propane pipeline
Killed operator

22. 1996 - Operator burned after hitting 8” gasoline pipeline

23. St. Paul, MN
City crew working on sewer line hit natural gas line
Killed 3, injured 11

24. 1988
Hit propane line
3 Workers injured

25. Dirt as a Hazard One cubic foot of dirt weighs 90-145 lbs.
The average collapse is 1.5 cubic yards (4000 lbs.).
The average victim buried under 2 feet of dirt will be covered by 3000 lbs., about 1000 lbs. of that will be on his chest.
The speed of collapsing dirt is often less than 1/10th of a second.

26. Time…Time…Time…
The average trench rescue takes between 4 and 10 hours.
Long rescue time allows for further deterioration of trench walls.
Rotation of rescue crews necessary to keep people fresh.

27. The First-In Company
Apparatus should be located no closer than 50’ to the trench and should be shut down.
Locate the victim and try to find out what was being done at the time of the accident from someone else on the scene.
Approach the trench from the end, never from the side and stay as far away as possible.

28. The First-In Company
If the victim is conscious, he may be able to rescue himself if a ladder and/or shovel is lowered to him.
Call Orland Dispatch (708/ ) and activate a CART box for a trench rescue.
Keep everyone back from the trench and shut down all machinery on the scene.
Shut down all roads and railways for a 300’ radius from the scene.

29. The First-In Company
Identify any utilities that my be marked by JULIE at the scene.
Orange – Communications
Red – Electric
White – Excavation Boundaries
Yellow – Natural Gas
Green – Sewer
Blue - Water

30. The First-In Company
The location of an unconscious or trapped victim can be marked with paint or dry-chem at the edge of the trench.
Ground pads will need to be laid around the edge of the trench.
The spoil pile must be moved a minimum of 2’ away from the edge of the trench. This must be done while working off ground pads.

31. Water, Water Everywhere…
Prior to the rescue team entering the trench, all water must be evacuated. This includes water from a main break, ground water and rain water.
Small amounts of water can be removed with a sump pump in a 5 gallon bucket.
Larger amounts of water or water which is flowing can be removed with a vac-truck.
The truck must be set up 300’ away and have a safety valve in line with the vacuum hose.

32. Incident Command Establish a trench team command structure
Rescue Officer (required) – Officer in charge of the rescue and designates other rescue sectors.
Rescue Safety (required ) – May be in addition to the scene safety officer and trained to the level of the incident.
Rescue Operations – Officer who runs the rescue.

33. Medical Care for the Trench Victim
Establish medical care for the victim as soon as protection is established and victim is accessed.
Prepare for open & closed fractures, chest injuries, spinal injuries, crush syndrome, hypothermia, dehydration and hypoxia.
Give the victim a head, eye and respiratory protection as soon as possible.

34. Trench Rescue Hazards Hazards are not obvious
Secondary collapses are common
Dirt is heavy and moves fast
Rescues are usually long-term operations
Backhoes are not safe for victim rescue
OSHA has trench limits and regulations
Buried utilities can pose a threat to rescuers
Impact or entrapment from falling debris or equipment
Unprotected trenches are dangerous
There may be inadequate equipment for shoring
Possible legal liabilities for fire officers

35. The End