Trench Collapse Rescue & Shoring
By Joseph DiBernardo
The housing construction market may appear to be slowing and construction site accidents are less, however people working in excavations and trenches still exist.
Recently in Setauket, Long Island, two workers were buried, one to the knees and one to the chest as they excavated by hand to expose and water proof a foundation. They were able to self extricate prior to arrival of the collapse team. There was no shoring in place. Each laborer was transported to a local hospital with minor injuries. These were the lucky ones. In Brooklyn, New York a worker was swallowed by a 10' deep trench, when the side of the trench collapsed burying him. He too was waterproofing a foundation; unfortunately he succumbed to his injuries.
Between 1992 and 2001 there were 542 deaths related to Trenching and Excavation accidents, 54 annually. 76% of the deaths were caused by cave-ins. Nearly half were employed by companies of 10 or less employees, typically 'fly by night' companies that take short cuts and work without the required shoring and safety practices under the mind-set that time is money. 75% of the deaths were laborers.
The fire service, including NFPA has adopted the OSHA standards 1926.650/1 (29CFR1926) as its standard governing fire department operations at these incidents. For example OSHA tells us that industry must ladder a trench if it is 4' or deeper and must use shoring it if its 5' or deeper. The fire department has adopted to follow these regulations and should.
Fire officer and firefighter discipline is a must when approaching and operating at trench and excavation accidents as well as any technical rescue. The attitude of running in when others are running out will get you killed or seriously injured at the least.
Trained members shall approach slowly, find the person in charge and try to ascertain what happened, how many are hurt or buried, their location and what were they doing. Orders must be given to ensure that the adequate units are responding, request a VAC truck to the scene, the area is secured, keep apparatus 100' away, shut down any equipment, utilities are shut down and clear the area of vehicles for the incoming collapse units. Ensure that no one enters the excavation including the other workers. They should be kept away from the area after ascertaining information from them.
Upon arrival of the collapse units, plywood pads will be placed around the trench to help distribute weight of the firefighters preventing further collapse. 2"X12" planking is placed between the lip (edge) of the trench and the spoil pile (pile of removed dirt). OSHA says this area must be kept clear for 24", it never is. The spoil pile is always found on the lip of the trench. This may cause a collapse (spoil or lip slide). This may be the initial cause of the collapse or may be a secondary or tertiary collapse trapping rescuers.
After the location of the victim is ascertained, trench panels are placed as close to the victim as possible. These panels are secured by either pneumatic or timber shoring. Typical collapse units carry four or six panels with additional lumber to make more on scene if needed. Rescuers will use as many as necessary to safely protect themselves and the victim.
Use of the vac truck proves advantageous. The vac truck can suck huge amounts of sand and rocks out of the trench. The truck, if full to capacity can dump its load on scene and continue to operate. The rescuers can easily use the large hose off of the vac truck's boom, which can be placed directly over the trench or as close as possible without causing vibration which may cause further collapse.
Patient packaging shall be performed considering traumatic injuries. Soil moves at 40 mph and is extremely heavy, up to 2700 pounds per cubic yard. Rope systems and high point anchors may also be required to safely remove the packaged patient.
NFPA 1670 Chapter 11 - Trench and Excavation Search and Rescue, governs the fire department operations at these incidents. This standard, as other Technical Rescue Standards is broken down into three groups: Awareness, Operations and Technician. Awareness level is for all personnel of the agency responding. This level will ensure the safety of all personnel on scene, but does not allow members to enter the trench or excavation. Operations level is the most common level and is where members will actually shore and enter the trench. Operations level personnel shall only enter trenches of 8' or less and they shall not intersect other trenches (no 'L' or 'T' Trenches). Technician level allows members to enter deep, greater than 8' and intersecting trenches.
Trench Rescue can be extremely dangerous if shoring and common safety practices are not conducted. Don't become a statistic. Stay out of the trench until it is shored. Call for your collapse unit and technical rescue team early, as well as the vac truck from your local government via the fire dispatcher. Some towns sub-contract vac trucks, so check how to get one now - not when you need it.
If your agency isn't trained in trench collapse, find out who is and drill with them. Become awareness level certified and stay safe. For more information on Trench & Excavation Shoring and Rescue go to: www.LongIslandRescue.com.
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