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Collapsing railcar during multi-forklift unloading. 2:34 video:
https://www.youtube.com/watch?v=fPcRV1DMN8E
Previously:
https://www.homemadetools.net/forum/...070#post138031
https://www.homemadetools.net/forum/...126#post125968
https://www.homemadetools.net/forum/...367#post127013
https://www.homemadetools.net/forum/...226#post126499
https://www.homemadetools.net/forum/...289#post121698
https://www.homemadetools.net/forum/...720#post123927
I saw that coming as soon as the end driver picked up and did absolutely nothing to correct his forks tilting downward.
Any one of those lifts that moved back slower than the others would also cause that.
They all needed a stack of what a friend of mine calls mafia blocks on the back of them. His large forklift is capable of lifting its 30,000 lb rating but anything over 20,000 K he stacks a 10,000 lb block on the back. He says it is there for the just incase. When I had my 25,000 Taylor we welded a 6in. thick steel plate the same size as the counter weight on the back so that the forklift would always run out of lift power before the back got light. We sold it to a guy who welded another 10 inch thick plate added 10,000 lbs to the fenders turned the hydraulic pressure up to 3000PSI from the 2000 PSI setting added 2 more hoist chains foam filled the tires then had it certified as a 50K forklift He said those old Taylors the size of that one because of its shared components and frame of much large cap. forklifts, could actually lift 80K before the mast and carriage reached their safe limits. I don't know I was happy with being able to lift 25K and still be able to drive over rough terrain
In the rail way lifting If the load is 100K you don't use 4 25K lifts you use 4 50k lifts that way if soughing does not go as planned and the choreography is a little off you have extra cap to help keep you out of trouble.
Case of wrong tool wrong job, uneven ground with the ballast falling away from the track. Whats wrong with a gantry lift over the rail car trailer, easier to construct and a whole lot safer. Spreading a load across what 4 forklifts of varying size and capacity umm. To say i saw it coming was an understatement. 1x bigger forklift able to lift 1.5 times the actual lift weight required wouldn't have been a miss.
Its hard working in Africa and India and not being able / or being powerless to say anything when you watch this **** unfold.
But you have to admire the pure genius when they pull it off and it works as it should. Jon has already posted video clips of guys loading a JCB into the back of a lorry, it might work 99 out of 100 times then **** happens. Its the old mith about the guy with the hand grenade, if you lie face down on the ground and place a hand grenade out to the side at arms length 9/10 time you will survive due to the angle the explosion projects, my question has always been how successful was the guys 11th attempt. 0 points for effort.
Well, doesn't seem to be neither in India nor in Africa - in my head the acronym "BNSF" on the flatcar end means
"Burlington Northern & Santa Fe"
Even worse: the flatcar seemed pretty much brand new itself.
The thing is we don't know but they may have already unloaded a dozen or more flat cars exactly the same way without incident. This may have even been a case of laxation of procedural protocol due in part of the ease of off loading several cars previously. Or one operator could have sneezed causing him to jerk a lever or step on the gas but what ever the reason there still no getting around the limited safety factor of possible overloading calculated for the pick.
All it takes is one driver to let up just a touch and it’s all over. Like others have said we all saw it coming. When the guy on this end raised is forks did all the others follow suit? I think not and that’s what triggered the collapse.
Having watched twice with time to think between, it seems one mistake made was not tilting back when the stanchions of the rail car were cleared. As noted in a previous post the ballast is tapered, dropping the front of the lift as they backed up. This creates a tilt too far forward condition, load too far in front of the wheels. Not only would tilting back have made a difference with the uneaven ground but would have moved the load closer to the front wheels increasing the stability of the lift with a load so close to the limit. Can always tilt forward when the load is closer to the ground. Then the forks can act like wheelie bars if things go wrong. If you are going to push the limits, best think of what will happen when those limits are exceeded and how to at least keep to the knife's edge, not past, it can be a long drop.
Eric
Like jdurand said, except that my analysis would be that any forklift moving ever so slightly FASTER than the others would "drive out from under the load," transferring his load further forward relative to his front wheels. As he began to lose his load it would transfer to the others. Also, as his mast tipped ever so slightly forward his lift vector would push the load out, further disturbing the forces on the other lifts.
Coordinating three (or four? I couldn't see) forklifts with powerful engines to move in exact synchronism would be a challenge. I wonder if this unloading mode had been used successfully in the past.
Note: I have NEVER operated a forklift. Just physics.
As pretty much all of us have said there were a possibility of a multitude of mitigating factors that could have and would have caused the load to be dropped.
Even the act of tilting back once the stanchions were cleared needed to be carefully executed and done at the slowest possible rate. all it would take in doing that would be 1 guy being a little ambitious while the other were taking their sweet time he would have noticed the rear of his forklift begin to rise then in a panic would have lowered his forks slightly causing the others to have more load then it would have been just what happened a domino effect.
We've unloaded stuff here at my place using 3 lifts 2 on 1 side to do most of the lifting and 1 on the other to counter and over balancing effect when doing it like that though you can't tilt back unless there is enough room for the fork lifts to run under the load. In my case 2 machines were actual forklifts and the 3rd was a backhoe with the loader bucket removed and a carriage & forks installed that time we were picking up a 18,000 lb trailer 2 machines could lift 8K each and the other one only 6k but even with 22K total cap being on sand we had little margin of safety to work with and we didn't have to move the machines just lift high enough for the truck to drive out from under, the next time we made a heavy pick was my pencil sharpener lathe that weighs close to 26k. For that I built my A Frame Gantry which is strong enough to hold the entire lathe but we put 1 8k fork lift on one side and my backhoe on the other. Most of the weight was held by the gantry giving us a great margin of safety for that pick.
In the many years I was in the factory setting doing machine repair and millwright type work I saw many machine movers do magic in some of their moves. One time I picked up a machine with forks at what I thought was a good place to swing so all the CG was low. I needed to sit down and get a better pick. As soon as the weight was released from the fork, the machine tipped back and fell over backward. Made one hell of a boom but fortunely it was shop made machine weldment and was still functional. The only thing damaged was my ego. It was near lunch time and when I got back from lunch, there was a rubber chicken hanging from a noose on the front of the machine. For the next 20 years until I retired, anytime anyone made a mistake, they got the chicken until one day it disappeared. What I learned from me dropping the machine, was always have a piece of wood or cardboard on the fork for friction and have the machine chained to mast. The machine movers always said steel on steel is no deal. Lift and tilt back to get CG closer to the machine and move very slow.
A piece of old conveyor belting or a rubber mud flap from a truck is what I have used the mostQuote:
Originally Posted by stillldoinit
what they needed was a Peugeot 205 car, I drove my lathe 440lbs from Yorkshire to Cumbria, i figured it was no heavier than two fat adults in the back, although that may have been true the COG was that well thought out. any speed over 50 and the car started to weave like a roller skate. The relationship with my girlfriend was still new and it was her car, ooops. That little car was built like a tank. The lathe was man handled into the car by 4 men at Harrogate show ground and unloaded by two farmer boys in Brampton. Would i do it again, hell yes - NOT.