This past weekend I was conducting a training program and included a lifting scenario for each group to complete. The lift was a roughly 30,000 lb. wheeled loader. The group was using multiple points of lift and this included two (2) lifting bags at two points in the rear of the loader. At one lift point a 26 US ton lift bag was utilized. There were no sharp edges in the area of the lift. The group had lifted the machine and had stopped to debrief the scenario. Before debriefing, the capture cribbing points were checked and all were “snugged up”. During the debrief, a few points were discussed (including appropriate cribbing selection/use and wedge use) and then the group was going to lower the machine. I did point out the use of an unsupported layer of 2×4 and I had some minor concerns with the way the wedges were placed in the capture crib next to this.
All personnel were in place to lower and they had to raise the lift bags slightly to be able to remove capture cribbing. As they began to inflate the lift bags, the instructor with the group observed the 26 ton bag beginning to fail and he immediately stopped the evolution and moved everyone back in the event the bag failed violently. All capture cribbing remained in place so there was no dramatic drop of the machine. The instructors were able to “undo” the lift and the machine was lowered, and the bag was removed and taken out of service.
As you can see in these photos, the lift bag did not “blow out”, but rather leaked air into the space between the bladder and the shell. It remained “inflated” (and I think the bubble grew even more after it was out from under the load). This lifting bag is 20+ years old, in relatively good condition visibly, and had been 3rd party tested sometime within the last year. The agency conducts regular training and maintenance on all their rescue equipment and was already planning on replacing the lifting bags in the next year or so.
This is not the first time I have seen this happen and I shared these photos with another colleague who does a lot with lifting bags and we agree that this was plain and simple a lift bag failure. In this case they were not trying to exceed the bag’s capacity. The students in this case did nothing to cause this. (This was actually the 2nd or 3rd time this bag was used during the training day.)
In general I think we may – no, more like we will – be seeing more of these issues as lifting bags “age out”. There are several take-aways from this for all of us as rescuers:
- Make sure to visibly inspect all lifting bag systems prior to use. Although this bag showed no outward signs of impending failure, there are some bags out there that look really rough.
- Make sure that systems are annually tested, and any lifting bags over 10 years old should be considered for replacement.
- Make sure rescuers keep up with capture cribbing. This is a perfect example of how “lift an inch, crib an inch” can prevent a major problem because if the bag would have failed violently, the cribbing was in place to stop the load from dropping..
- Another area of importance is rescuer placement. Again, trying to keep rescuers from standing directly in front of lifting bags during an operation.
- Lastly, make sure that an incident safety officer is designated. In this case, the instructor was acting as one of the “safety people” and observed things going wrong and was able to stop the evolution before anything else could go bad.
In this case, “nothing happened”… That is a good thing! The agency is obviously going to step up their replacement program, but it’s better that it failed in a controlled training environment rather than in the street. A good learning scenario for everyone!