I have a question if anyone can point me to what would have likely caused this damage. We had the rope replaced 3 days ago, on day 3 this was noticed. It is locked out and waiting for a new wire rope. I'm curious if installation or manufacturer defect could be an issue? Thanks for your input,
Is the SWR the correct rotation for the winch?
A few possiblilities come to mind. #1- if they installed the becket first, and then wound all the cable onto the drum, it would have pushed all the drum cable twist to the becket. They would have had all the cable laying out on the floor, off of the cable spool, to do that when they installed it. I don't know why they would have done it that way, but its possible. #2- wrong rope for the application- some rotation resistant ropes can't be used in multipart lines. They are meant for drum to a ball only, and the twisting from going through a block will give them core damage at the becket. It will happen in truck cranes over time when running block with a rotation resistant rope that isn't meant for multipart. #3 they gave the becket 10 or 12 twists before pinning it up, to try to cure cable twisting the block up, but that's usually only necessary on running non rotation resistant rope with a lot of cable on a long boom. Looks like you are a overhead crane without a lot of fall, so I don't know why they would have turned it before installing. Either way, you've probably got some core damage in that last 6' of cable. If there's extra cable on the drum that you could still get the block to the ground, you could remove 10' of cable and reinstall the becket and see if the problem persists, then you would know if its a installation issue, or the incorrect cable. It does look like a left lay cable on a right to left feeding drum, so I don't think its the wrong cable lay.
I see Saddle clamps. Very big nono by us, fist grips only. Had a bunch of cables the ubolts cut thru the lays when pulled to capacity. Fist grips are way safer.
Before thinking about installing a replacement rope (I assume using the same personnel) this would give you an idea what caused the problem in the current rope and IMO should be done in order to remove any "labour vs material" doubt irrespective of whether or not you intend to attempt to salvage the existing rope. Unless you get to the bottom of what caused the damage in your photos then you run the risk of having exactly the same happen to the replacement rope. Does the overhead crane manufacturer's documentation contain details of the correct wire rope specification for this application.?
There's no pressure/weight of any kind on the saddle clamps, all the pressure/weight is taken by the becket. Has no bearing on his issues at all.
Just curious, is the dead end brazed over completely? Hard to tell…..
I am leaning towards installation error. If the rope was installed by paying directly off a shipping reel, any twist in the rope would remain in the system and work its way back toward the end termination. Often times this kind of twist is observed immediately after the initial run test and the bottom block will twist the parts so severely it cannot be operated. If not too severe, sometimes the twist can be removed by removing the end termination pin and rotating the wedge socket a few turns in the opposite direction of block twist. This can be avoided by first removing a new rope from the shipping reel and laying the entire length of rope out on the floor to remove any twist and allow the rope to relax before installing. If using the old rope to pull the new rope through the reeving, use a swivel connection between the two to avoid transferring any twist from old to new. Finally, always follow manufacturer's procedures for rope break-in.
There is a lot to know about wire rope. That’s about how much I know about it.
In that case you reallly need one of these. Everything you need to know about wire rope in one easy reference - and no, my copy isn't for sale........ https://onlineshop.oxfam.org.uk/ncb...VhOvtCh3BDQ0rEAQYASABEgLAZfD_BwE&gclsrc=aw.ds
In the early days of my career I got a lesson on loading line from a spool onto the drum of a brand new Link-Belt crane. I was working with a guy who was supposed to know his stuff about cranes. We mounted the spool on a pipe that was across saw horses and pulled the wire onto the drum with the power of the machine. Unfortunately we had the line coming off the bottom of the spool onto the top of the drum. We should have had the spool situated so the line came off the top of the spool and onto the top of the drum. Fortunately the new owner came by and saw our mistake when we only had about half the line loaded. We had to pull all the line off the drum by hand and drag all the line off the spool now to get the twist out. A couple of hours reeving the crane now took over four hours. There is a lot to know in this business and a lot of mistakes can be made.
I imagine that wire rope is like synthetic rope, it would be frowned on to drag the cable through the dirt??
Back then it wasn't much thought about. As I recall you had a choice of rope. Right lay, left lay and lang lay. You could also get wire rope center or fiber center. The only other variable that I remember was the number of strings per strand and number of strands per rope. I seem to remember there being a lube available but we didn't put it on back then.
I'm thinking that the grit will cause abrasion between the strands.
Maybe ask a logger dragging line out in the brush from a yarder about that. New line is so tight the only place dirt can stick to it is on the outside of the rope and that is if it has a lube or protectorant applied.
I have seen that same mistake made respooling drums on tow/recovery vehicles. When I bought the 3/4 for the tow truck I bought from Oregon Rigging, he automatically asked which side of drum was anchored and rotation. Personally I don't trust anything that isn't swaged with zero kinks. I witnessed a 5/8 in flight once, don't want to see that again.
Most cable pans back in the day carried 2 spools of rope partly for this reason. The idea was when the rope needed replacing all that was required was take the rope out of the Becket and pull a section threw using the winch, cut the unwanted length off the winch, reconnect and get back to work.
You forgot one lay, ordinary lay.
Ordinary lay is also known as regular lay
Isn't regular lay the goal of all of us?
Thank you everyone for your opinions, I appreciate the different perspectives. We ended up having a new wire rope installed. This one is good. I was asking the technician why that happened and I was told the bolts for the rope anchorage clamps were stripped and they came loose. Just curious if that's plausible?
OK, so according to the technician the rope anchorage clamp bolts on the drum (seeing as that's what your photos show) were "stripped". I assume that he installed new ones.? Did he show you the old ones to back up his statement.? Were you billed for new anchor bolts.? And then would he kindly explain just exactly how a problem with the clamping of the rope at the anchorage point on the drum would result in the damage shown in your original photos which was right at the opposite (dead end anchor) end of the rope.? My opinion. I think he's full of ****.
Here's another question. How did he determine that the threads in the drum for the rope anchor clamp bolts were not damaged.?
Are you talking about the anchorage point on the drum itself or where the rope clamps are on the wedge socket? I can't see the clips and on the wedge socket clearly but think a clear photo might reveal a problem there.
I think its more likely that the socket head recess in the drum anchorage clip bolts were damaged (stripped) rendering them nearly impossible to remove with an Allen wrench. I have experienced this very scenario with these hoists. Alternative measures would be needed to extract the bolts (use your imagination) and YES, the bolts (and sometimes the clamps) must be replaced when this happens. If the hex recess is stripped, the bolts certainly could not be tensioned properly when re-installed. Which raises the question: Why would anyone have re-installed those bolts and worse, why would anyone return the hoist to service if those bolts could not be properly tensioned? Now, with that said, I think Nige is correct in calling BS on that explanation. Don't see how that has anything to do with inducing twist at the dead-end. I would request documentation of the repair including any new parts used.
I'd request documentation backed up with before & after photos and a list of parts replaced. The original photos on Page 1 of the problem in the live end of the hoist rope give me the impression that 2 Crosby clamps along with a short piece of the rope had been used to add a safety to the dead end as per the illustration below which only has one clamp but it was all I could find.
You are correct and this is typically how the manufacturer specifies this termination be configured. There are manufacturer and model, specific tolerances for wedge protrusion below the socket, length of rope tail and distance between that short piece and the bottom of the socket. When done properly the termination is very reliable. I believe the cork-screwing effect in the rope was a result of installation error by failing to remove inherent twist from the rope manufacturing process prior to reeving it through the hoist and spooling on the drum. The installer was likely running behind schedule if struggling to remove those rope clips from the drum, leaving less time in the end to properly lay out all of the new rope, remove all twist and reeve the system. Hopefully the installer took the time to properly re-set the designed limit switches.
Rope damage isn't from the drum termination bolts being loose. Once there's a couple wraps on the drum, the drum clamp doesn't hold much tension. He's feeding you a line of B S. I think they installed it incorrectly, and are just covering their butts. But he has to tell you something....
The photo isn't clear enough to even see if there was a dead strip attached. It actually looks like the bottom clamp may be attached to the live side of the connection. I was always taught that the U bolt goes over the spacer rope and the clip side goes on the tail. The drawing is also showing the clip attached with the U bolt on the tail instead of over the spacer. When installing a new line we always loaded the drum up first and then reeved in the hook block which would normally allow the twist to come out. That looks like someone tied the dead end and then loaded the line on the drum.
Let me know if these pictures reveal anything. Thank you.
Yes. They confirm what I thought. And that's what the photos show.
Are those the first replacement or the second. That is the way we were told to do the clips. I do question how far that wedge is sticking out the bottom of the socket though. Maybe the crane guys can speak to that?
Something I was told years ago by a rigging pro---Never saddle a dead horse,
Thats true for eyes but in this case, the u-bolt has to grip the tail and the saddle the spacer piece. The rope will slip through the saddle easier than the u- bolt and in this case for safety, the tail must not slip through the clip otherwise it would defeat the purpose of the safety clip on the dead end of the tail. On an eye, if the rope slips through the clip on the live side, it will only make the eye smaller(tighter). Thats why we don’t saddle the dead side on an eye. If the dead side was saddled,it could pull loose
So your saying the clamps in the last photo are wrong?
If you’re referring to the pictures in post#30 i would say they are wrong but i would do what the manufacturer of the crane/hoist specifies for legal/safety reasons. The illustration in Nige’s #26 post is what i would believe to be correct
But in this particular case there are two dead horses......... In the specific circumstances of the dead end rope coming off this anchor I can see the logic of installing the Crosby clamps "backwards" compared to the conventional way of installation.
What about how far the wedge is sticking out the bottom of the socket?
That would suggest the Becket is to large for the rope I'm guessing.
To the OP. What brand is the hoist for your EOT crane.? Do you have an Owner's Manual for the hoist.? It will generally not be the same as the manufacturer of the crane.
Its not unusual for a little of the becket wedge to protrude. It looks like a european style becket. The curves in the wedge and the inner curve of the becket, all look right in the picture. I wouldn't be too worried about the way the tail is clamped either.
A poured socket would be more secure and efficient.