Plan in advance for a confined space rescue. When a worker needs to be pulled out, every second counts.
There’s no time to waste if something goes wrong in a confined space. If a worker gets hurt or the gas detector alarm sounds, you’ll need to immediately execute your confined space rescue plan. Having the right confined space rescue equipment on site and ready to go is key to a successful rescue operation.
Confined space non-entry rescue equipment
OSHA’s confined space in construction standard requires employers to perform a non-entry rescue whenever possible. Your first step should be developing a confined space rescue plan that’s specific to the space. The next step should be moving your confined space retrieval system into place. Too many contractors think they can slap together a jury-rigged solution, but keeping a rope near the entrance to the confined space to throw down to your workers is not a viable rescue plan.
The equipment you’ll need for a confined space non-entry rescue will depend on whether the space is accessed horizontally or vertically.
Vertical entry spaces
For vertically accessed confined spaces such as manholes, options for confined space rescue equipment include a self-retracting lifeline and/or a mechanical winch with either a tripod, Davit arm, or other approved anchor point.
Horizontal entry spaces
If you’re working in a space such as a vault, culvert or viaduct, you may need a horizontal entry confined space rescue plan. There’s no standard rescue setup for horizontal entries. You’ll need to look at the configuration of the space, figure out what challenges you’d have trying to get someone out and then devise a creative solution that would retrieve or rescue the entrant in a timely manner based on the potential and known hazards in the space.
For example, you might be able to pull your worker out of a viaduct using a bogie cart connected to a line. If that’s your planned non-entry rescue solution, make sure you have that cart ready to go every day.
Self-retracting lifeline vs. mechanical winch
To pull workers out of a vertical-entry space, you can use either a self-retracting lifeline (SRL) or a mechanical winch as part of your confined space retrieval system. Both types of lines attach to a D-ring on the worker’s harness.
The main advantage of an SRL is that it does double duty, acting as both a rescue line and a fall protection system. If someone slips off a ladder, the lifeline will immediately lock in place to prevent the worker from falling further. (It works the same way a seatbelt does when you come to a sudden stop.) Whenever there isn’t a fixed or approved portable ladder to use for access and egress into the space, a winch and SRL combination is recommended for any emergency retrieval plan. Just be sure the worker knows how to use an SRL before they enter the confined space.
The mechanical winch line does not have that fall protection capability, so you should use it only to lower people into a space and/or lift them out of it.
Inspect your winch line or SRL regularly to make sure the line is free of any damage and that the SRL engages properly throughout the length of the line.
Tripod vs. Davit arm
Tripods are a long-time industry standard in confined space rescue equipment. The legs straddle the entrance hole and a strap or chain wraps around the legs at the base to keep the tripod secure. Tripods have a mounting area at their center where you can attach an SRL or a winch line. They work well in most situations.
The Davit arm, however, is a more versatile choice for your non-entry rescue plan. It’s a device that gives the entrant and attendant easier access to the entry. The davit arm also offers a good method of retrieval when a three-legged tripod can’t be positioned over the opening of the space. The hitch mount can attach to a pickup truck, while the freestanding mount enables the Davit arm to be placed on the ground. A Davit arm is very lightweight and takes little time to assemble at the site. Another advantage: You can attach a gate to a Davit arm, which lets you block the entrance to the confined space.
Inspect your tripod or Davit arm regularly for loose bolts or weak spots in the structure.
The all-important harness
Even the best confined space retrieval system won’t be effective if workers aren’t wearing a harness properly. If the straps are too loose around the upper thighs, they could slip and cause a groin injury. If they’re too tight, they can cut off blood circulation. Three fingers should fit comfortably between the legs or chest and the harness straps.
Chest straps should be worn at upper chest height. On the back of the harness, the D ring should be positioned at shoulder blade height, centered between the shoulder blades.
Examine your harness each day prior to use for any signs of excessive wear such as fraying and loose or ripped-out stitching. Check the harness tags to make sure the harness hasn’t expired. If you can’t read the tags, you need to take the harness out of service.
Choosing the right confined space rescue equipment is critical to worker safety.