Crane vs. Clamp down part

A couple of months ago I posted a thread about my boss modification of the cranes in our shop. Some of you guys suggested that I should call OSHA, well I wasn't the only one worry somebody else did back then I didn't mention that another reason why I was (still) worry is because the electrical part of the modification was perform by our maintenance department ( the kind that want to fix everything with contact cleaner) including the overload switch. Well moving forward now the cranes got NO BREAKS and sometimes the remote control work and others no.The little one is a 15 ton with a brand new trolley on it and last night it meet it's match when one of the guys try to pick a part off the machine. The part is a base for a pump around 1.5 ton max the real problem is that the previous mentioned part was clamp to a table block of 3,000 pounds this block clamp to a 20'x10' table of one of the horizontal boring mills, oh in this table are 5 more of those 3000 pound blocks.
You guys be the judges. I know is pretty MORONIC try to pick a part with out checking for clamps firts but also that's a brand new crane we talking about there's any chance the maintenance guy didn't set the overload switch right?

Well at least now you know the welding was good.

oinotnasiul said:

View attachment 113159View attachment 113158A couple of months ago I posted a thread about my boss modification of the cranes in our shop. Some of you guys suggested that I should call OSHA, well I wasn't the only one worry somebody else did back then I didn't mention that another reason why I was (still) worry is because the electrical part of the modification was perform by our maintenance department ( the kind that want to fix everything with contact cleaner) including the overload switch. Well moving forward now the cranes got NO BREAKS and sometimes the remote control work and others no.The little one is a 15 ton with a brand new trolley on it and last night it meet it's match when one of the guys try to pick a part off the machine. The part is a base for a pump around 1.5 ton max the real problem is that the previous mentioned part was clamp to a table block of 3,000 pounds this block clamp to a 20'x10' table of one of the horizontal boring mills, oh in this table are 5 more of those 3000 pound blocks.
You guys be the judges. I know is pretty MORONIC try to pick a part with out checking for clamps firts but also that's a brand new crane we talking about there's any chance the maintenance guy didn't set the overload switch right?View attachment 113155

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one of the reasons i like to use nylon slings or straps is when they have a heavy load they stretch and give you a warning. i also tend to pick 1/4" at a time and if one side not coming up the part tilts which can see and give warning something not right.
........ we have a few fixtures with bent hold down clamps and threaded rods. it is rare and i like to walk around twice to confirm all hold down bolts are off but it probably happens to most people once in a awhile to miss a bolt. about the only thing i recommend is always pickup slowly.
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1) to confirm part is not being held down somewhere
2) part could swing hard side ways if hook not exactly above balance point
....... for myself i would rather have a nylon strap break on overload than something on the overhead crane break. either way if something breaks the whipping action can cut a person in half. not good to be too close.
........ steel load chains and steel cables and hooks can bounce around pretty hard

Seems like a lot of consistency here.

I mean no disrespect but if the quality of crane work is akin to the quality of photography and clarity of your post . . .

A proper hoist setup would stall the motor before snapping the cable. Regular inspections and certifications are required in our shop. Either you have the wrong cable, or it was worn out . . . Pictures are too poor to draw any conclusions apart from the idiocy of the operator.

Does that guy in the lift have a harness on and properly attached to the basket safety rail?

motion guru said:

Seems like a lot of consistency here.

I mean no disrespect but if the quality of crane work is akin to the quality of photography and clarity of your post . . .

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Sorry for the quality English is no my first language and still learning how to use this phone.But I laugh about the consistency

motion guru said:

A proper hoist setup would stall the motor before snapping the cable.

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Well maybe not.

We run serious duty jib crane hoists, and 2-blocking one will snap the cable right now,
no grunting. Hence the limit switch is tested regulary, and it's always explained
that the limit switch is NOT to be used for everyday work.

Switching over recently to Demag chain hoist's, they have an overload clutch.

digger doug said:

Well maybe not.

We run serious duty jib crane hoists, and 2-blocking one will snap the cable right now,
no grunting. Hence the limit switch is tested regulary, and it's always explained
that the limit switch is NOT to be used for everyday work.

Switching over recently to Demag chain hoist's, they have an overload clutch.

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That doesn't seem correct, like the OL is improperly set. Why risk dropping the load when you can just stop the motor?

Cole2534 said:

That doesn't seem correct, like the OL is improperly set. Why risk dropping the load when you can just stop the motor?

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That's just the way it is.

The procedure is to raise the load 1", stop the "up" and check if the brake holds the load.
The brakes are tested and set often using test weights.

I was taking on old " Butler " planer out to be scrapped years ago when I was young and foolish. We were lifting the columns out of their locations. We'd removed ALL the holding down bolts from around the outside of the first column so we thought we were OK. What we didn't know was there was a rag bolt inside the column. 6 ton column versus 20 ton crane, no contest. We gave the crane driver the ok and he threw the up lever over a bit too quickly for my liking.
Next thing you know the crane gave a groan and an almighty shudder and the column jumped off the ground pulling a huge carrot like lump of concrete out of the foundation. Luckily no body got hurt.

In my lifetime I've seen the upper travel limit switch fail twice on overhead travelling cranes. On a ten tonner the ropes failed, dropping the load, hook block, chains, the whole shooting match. When the hook block hit the ground one of the dome shaped cast iron covers took off like a " Frisbee " and put a pretty big dent in the roller shutter door at head height ! Anyone in the way would have been dead. Again nobody hurt.

The other was an old 3 tonner that locked the ropes solid and the hoist part had to be scrapped. You could hit the ropes with a hammer and it was like hitting a steel bar.

Modern overhead cranes have load sensors. I was hoping to move a 3.5 ton milling machine with a 3.2 ton crane a bit back. I took the weight but no dice, the crane cut out right on it's limit. An old crane would have lifted the milling machine no problem.

Regards Tyrone.

Tyrone, more than a few people have been killed in man cages on construction sites from the upper travel limit failing and the hook getting stripped off the line.

Its one of the big pluses of the old manual chain falls, there great to learn on as you get a real feel for just what it is your doing.

I'd be worried about the block/hook raining down on me as well...

Like someone said a few posts up... At least you know the Fab work was good...

Glad nobody got hurt. Now, how sore is the guys butt who did that?

digger doug said:

That's just the way it is.

The procedure is to raise the load 1", stop the "up" and check if the brake holds the load.
The brakes are tested and set often using test weights.

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Spooky for sure.

Did you read the op?

Part was still tied down no lifting occurred.

Also if the block hits you(or whats left of you) wont matter cause you will be protected by the part.

Jashley73 said:

I'd be worried about the block/hook raining down on me as well...

Like someone said a few posts up... At least you know the Fab work was good...

Glad nobody got hurt. Now, how sore is the guys butt who did that?

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motion guru said:

Does that guy in the lift have a harness on and properly attached to the basket safety rail?

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Meh. He's a contractor...


I've used more than one crane that could only be called "dodgy".