We have all used or seen them used on countless CS entries. A tripod and winch set-up is by far the most common non-entry rescue system used in the USA. Because of this, it is also the most misunderstood and misused rescue system in the USA. Tripods are a GREAT tool when the entry is 100% VERTICAL; there is ample working space (both vertically and horizontally) to set it up properly, and ONLY ONE entrant! The most common use of a tripod is entering sewer manholes, which they were meant for. Tripods do NOT work on HORIZONTAL entries! Even if the first path of travel is vertical, but then the entrant travels horizontally AND a couple of feet beyond the feet of the tripod, the device is practically a hindrance to rescue at that point!
But I still see tripods set up on horizontal entries almost monthly. But what I really want folks to think through is the problem with multiple entrants and using a tripod winch system as the means for non-entry rescue (which is REQUIRED unless the configuration of the space does not lend itself to non-entry rescue or the non-entry rescue equipment will pose a hazard).
Here is what we have during an entry…
Let’s use an entry with two trained entrants. Both are wearing their 5-point body harness. One entrant has a tagline, a rescue grade rope tied to a rescue-rated carabineer attached at shoulder height and center of their back. This tagline’s other end is tied to a guardrail just outside the entry portal. The other entrant remains hooked up to the tripod/winch while they are in the space. Something goes wrong, and the attendant begins non-entry rescue by cranking on the winch and pulling up the entrant who remained attached to the winch. As the attendant begins to remove the entrant, the rescue team arrives and assists with removing the first entrant. Now here is where it goes BAD!
Four rescuers and an attendant stand over the entry portal, capable of seeing the unconscious entrant lying on the bottom of the tank! In their hands, they hold an empty hook at the end of the winch cable and the end of the 2nd entrant’s tagline… someone, please explain to me how the winch and tripod will be used to remove the 2nd entrant!!!! Keep in mind .146(k) explicitly states that if the entry is over 5′ in the vertical direction that, a mechanical means of rescue be available. What is the mechanical means available for the 2nd entrant???? Some students claim they can remove the winch cable from the tripod pulley, thread the tagline over the pulley, and pull the entrant(s) out with brute force. Yeah right… that’s when I get “Rescue Randy” and strap a 45-pound weight to his already 200-pound body to simulate the weight of a worker with an SCBA and other PPE and let the teams manually attempt to pull him out of the 30′ deep space. Then if that does not wear them out and cramp their hands, they have to stabilize him medically and then get him to ground level for transport to a medical facility. This little exercise has a lasting impression on those who participate!!! It is literally IMPOSSIBLE for even the three biggest, strongest, youngest, etc., rescuers to pull this off without that “mechanical means of rescue.” Dropping an entrant 30’ is NOT AN OPTION!!!
So, what can we do if a tripod/winch arrangement will not work? Well, and I hate to say this, but it all depends on the space being entered, the arrangement, and the working space outside the entry portal (both vertically and horizontally). This is why I feel that a RESCUE PLAN is needed for each permitted entry. Unless the entry supervisor is a trained and experienced rescuer, then a rescue team member should be involved in developing a rescue plan for the entry. I cannot tell you how often I have stopped an entry during a turnaround/shutdown where the entry was being done perfectly, but the rescue plan staging area was overrun with toolboxes, scaffold planks, scaffold poles, etc. Meaning the rescue team would arrive and have NOWHERE to set up their rescue.
Another serious error I have seen is when the overhead space is very limited. This prevents the tripod from being set up and extended to the proper height. This can cause an entrant that is being rescued from being able to be winched far enough out of the space so that they can be pulled out. I have seen entrants hanging 2-3’ down from the plane of the entry portal, and the winch has been cranked all the way up; but because the legs of the tripod could not be extended due to the low overhead working space, the entrant cannot be rescued using NON-ENTRY RESCUE!
These are just some things to consider when analyzing your non-entry rescue capabilities. Unfortunately, a tripod and winch is NOT the answer to all of our needs, and in fact, this system has very limited capabilities in most industrial facilities.
