Why Things Fall Off Cranes

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“A rigger learning the ropes” wasn’t prepared for Practical Dad Jokes

Funny how you always introduce things I didn’t know I wanted to learn

Another important thing: making sure everything is tight before applying the full load force. Sometimes straps get hung up or stuck in a crevace of the load, then once it's high up in the air, the strap slips free, potentially gets cut by a sharp edge, the load shifts into a drastically different orientation which makes it topple over another attachment point, and the straps get a big shock, potentially ripping them or overloading other things. Things relax especially when the load swings, oscillates or bumps into something. Classic case: you lift an I-beam with two basket straps, then they slide together, the beam shifts, slips out of balance or the straps get cut.

Enjoy your channel. I spent over 20 years working on cranes and rigging signs to be hoisted. I have also worked with construction helicopters who lifted heavy loads to the top of an 800’ building. I loved the challenge my job presented and I was blessed to never have an accident or lose one of my guys. Maybe you could do a show on construction helicopters. Thanks for the knowledge.

using the spring scale to demonstrate the increased force on a load suspended out of vertical was simply brilliant! I don't know why I haven't seen that done elsewhere, I had to learn it as a more abstract concept. I''m not a rigger per'se but pioneering merit badge (quite a few years ago haha) was probably my favorite, and rope behaves the same way as straps. fun fact, even the most well executed knot will reduce a rope's strength by 30% and a bad knot can reduce it a lot more.

The only incident of rigging failure I've witnessed was when a large change machine from an arcade fell approx.6 meters after one of its feet snapped off, causing the strap to slip. We later found that the failure was caused by shoddy welding. The feet of these machines are designed to bolt them to the floor, they shouldn't have failed and were marked as anchor points by the manufacturer.

Great info. We had an accident once on a heavy lift (~140T). I wasn't involved directly, but we all had a safety-standdown and training on it. It was a heavy machine casing that was to be lifted about 6 inches to work on footings. Was supposed to be combination of crane (using wire-rope slings) and hydraulic jacks. When hydraulics developed a slow leak and pressure slowly dropped, it was 'decided' to not lower the hook and just let it take up the weight (hook was rated for 150T after all). Unfortunately, the wire ropes were NOT and they failed spectacularly. Dropped the load those 6 inches and even at that short height, damaged footings and led to a lot more work. Fortunately, only one injury, arm laceration from splaying rope. Good lesson in, 'when things change, don't make up procedures on the fly'.

I love how much you connect the theoretical engineering to the actual work and construction process. Maybe it's just chemical engineering, but as one in training, I often feel like I'm taught that the people doing that manual work are beneath me somehow. Not only is that just plain wrong, but it's essential to listen to the people on the ground because they have familiarity and experience with the tools and equipment that I won't ever develop. All of my equations and models can be made meaningless by a simple defect, and it's up to their expertise to identify and fix it before it becomes a safety hazard. Learning how to listen and communicate with others is a critical, and I would say undervalued, part of engineering training.

Saw a rigging accident where they were doing a 50 meter lift inside a power plant. The riggers didn't have long enough cables so they WELDED two wire ropes together. Fortunately no one was under the load and there were no injuries. There were some people fired though.

I was an ironworker for 32 years, and I love your videos. We use steel chokers on rebar, and slings on epoxy coated rebar, and fiberglass rebar. Slings bother me, because of their tendencies to slip. When unloading a truckload of steel you can't always achieve the optimum picking points, and some operators refuse to wait for you to set the load down and readjust. It's not always the riggers fault.

reminds me of: a cop spots a guy dragging a chain up the middle of Main St. . . . being a cop, he stops him and asks "why are you dragging that chain up the street?" . . . guy answers "you ever try to push one?"

As a rock climber, this was fun to watch. Shout out for rope access too. Everything has a load rating, all the same stuff matters but the force are often dynamic as well. Can't think of a good engineering example of dynamic loading off the top of my head. I'm sure you could come up with some excuse! A deep dive on multi-point load equalisation for shifting force vectors on anchors would be interesting too! Must be some suspension bridge examples there?

My father worked at a General Electric locomotive manufacturing plant. The diesel locomotives were shipped overseas from the United States in large cargo vessels. One day a crane operator was unloading a locomotive and the ship started to tilt - and tilt some more - and even more - and the crane operator had to drop the choo-choo train into the ocean to prevent the ship from capsizing.

This was quite fascinating!

Rigging is used extensively in the AV production world. Any arena show you go to will have chain hoists supporting the PA and lighting trusses. Where the hoists attach to the structural steel of the building changes with each show, so riggers will walk out on the beams to create the rig points and attach the chains. The stage hands will usually have multiple riggers dedicated to the task.

Pretty good video. Exceeding the 30 degree angle is the biggest issue I see on job sites. The ticketed crane operator is almost always the most knowledgeable rigger on site. People think we just sit in cab and lift stuff but most started out rigging and still have to do quite a bit of it. Bottom line if not sure how to lift something ask crane operator.

As a fresh CE graduate, even finishing COSH, this kind of very specific topics aren't really given point during my study. That's why this kinds of videos are really helpful for a novice like me. Thanks for always giving us these very educational and easy to understand videos.

This content has me "hooked" I'll see myself out

Rigging, spreader bars, learning the ropes... those themes are really going somewhere :p