|
|
Rank: Advanced Member
Groups: Member
Joined: 7/20/2005
Posts: 336
Location: Alberta Canada
|
Does anyone have any info on this, news to me, may have been posted before? Sent to me today by a work colleague. 
|
|
Rank: Advanced Member
Groups: Member
Joined: 1/22/2008
Posts: 2,027
Location: Maryland
|
I don't like the looks of that photo, appears that the operators cabin got creamed!
Mark
Mark L.
It's what you learn after you know it all that counts
|
|
Rank: Advanced Member
Groups: Member
Joined: 6/30/2003
Posts: 4,918
Location: Melbourne, Australia
|
Probably not a great outcome, those cab pics don't look too hopeful :|.... Even the best jobs go bad.. Rowan.
1:25th scale CAT 375L excavator
|
|
Rank: Advanced Member
Groups: Member
Joined: 4/3/2008
Posts: 488
|
No pictures of this have been posted but ive had them for a couple of months now. The accident happened back in April i believe and kept fairly well secret for the obvious reason, no not a crane over, but the lack of a cab!!  Pictures like this scare the living sh*t out of me and i know Gaz feels prety much the same, we dont like seeing them. The reason the crane went over...................... the distinct lack of black rectangular lumps of metal on the blue counterweight tray when booming up a very long lattice jib for the first time.
in memory of Biscuit. dearly loved RIP 28.10.08
|
|
Rank: Advanced Member
Groups: Member
Joined: 9/22/2008
Posts: 632
Location: Chucktown!
|
Forgive me for asking the obvious, but how come there are some counterweights scattered about, and the others are still firmly attached to the crane? Is there some sort of system that mechanically latches them down, or do they just sit on top of each other?
Thoughts go out to whomever was in that cab. Never want to see such a sight.
-Alvin.
The beatings will continue until Morale improves......
|
|
Rank: Advanced Member
Groups: Member
Joined: 7/20/2005
Posts: 336
Location: Alberta Canada
|
[quote=jibtickler]No pictures of this have been posted but ive had them for a couple of months now. The accident happened back in April i believe and kept fairly well secret for the obvious reason, no not a crane over, but the lack of a cab!! Pictures like this scare the living sh*t out of me and i know Gaz feels prety much the same, we dont like seeing them. The reason the crane went over...................... the distinct lack of black rectangular lumps of metal on the blue counterweight tray when booming up a very long lattice jib for the first time. Thanks for the info, I have several other pictures too but this one had the most detail of the crane that could explain what went wrong. Figured that if they made it all the way over here in e-mails its likely not hush hush anymore.....
|
|
Rank: Advanced Member
Groups: Member
Joined: 6/1/2006
Posts: 4,065
Location: Dublin Ireland
|
a truely horrible sight
I'd be interested in the reason why she tipped,if there was insufficient cw's on the tray surely it wouldn't boom up from the start?
Why is "phonetically" spelt with a "ph"?
... It's better to be silent and thought a fool, then to speak up and remove all doubt
The complex of Newgrange was originally built between c. 3100 and 2900 BC,[2] meaning that it's aproximately 5,000 years old. According to Carbon-14 dates,[3] it is more than 500 years older than the Great Pyramid of Giza in Egypt, and predates Stonehenge by about 1,000 years.
|
|
Rank: Advanced Member
Groups: Member
Joined: 9/22/2007
Posts: 5,860
Location: Louisville
|
Wow, that's a horrible sight to see! It too, scares me! Alvin-the Cws do just sit there, but I think there's also some kind of pattern on the tray that keeps them from sliding around, but they also wrap chains around them and strap them down, the ptc is probably your best example to look at. Here's the 31000.. this is the newer 31000 with regular maxer weights, not strapped down, just sitting, but does have something to keep the bottom one from sliding off the side  heres one of chris' pics hes got of the other 31000 weights  and heres one stolen from bobs page of his ptc, the chains hold the weights in place 
Brandon my youtube channelMy Facebook Page
|
|
Rank: Advanced Member
Groups: Member
Joined: 11/11/2006
Posts: 3,421
Location: UK
|
Saw thea while back on Facebook, apparently the driver was ok, never nice to see.
Heavy Cranes
|
|
Rank: Advanced Member
Groups: Member
Joined: 4/13/2011
Posts: 1,021
Location: California
|
|
|
Rank: Advanced Member
Groups: Member
Joined: 7/20/2005
Posts: 336
Location: Alberta Canada
|
gbarnewall wrote:a truely horrible sight
I'd be interested in the reason why she tipped,if there was insufficient cw's on the tray surely it wouldn't boom up from the start? I was thinking the very same thing, modern cranes have very sophisticated computers, that have to have operating modes keyed into them that are designed to prevent accidents like this. I can recall back in the early 90's, there was a 80t Grove AT on site, the load was well within the limits of the crane's capabilities in MODE 3. That meant that the crane had to be equipped with all 3 layers of CW. At the time of the pic the crane computer was set-up in MODE 3 but un known to the operator, the crane was physically set up in MODE 1, base CW only. The op went to make the pick and could feel the crane getting light. Baffled by it, the op went out for a look and to his surprise found the other 2 layers of CW on the boom dolly. Fortunately there was no accident , but it's an example of how things can and do happen. It would only be speculation in this case, that the crane computer may have thought it had a loaded tray, and permitted the raising of the boom, another puzzling aspect is why was the boom being picked over the side and not directly over the toes of the tracks. Sometimes it's procedure to block the tracks to pick max boom or extra heavy loads. Only those involved can tell the story....
|
|
Rank: Advanced Member
Groups: Member
Joined: 4/3/2008
Posts: 488
|
Sophisticated computers or not, unfortunately you still have a human being at the controls. With all cranes, there ia the overide key which is used for rigging the crane which will basically turn the crane into pure manual function and turn off just about every overide function including picking of the boom off the ground without any counterweight in the tray.
in memory of Biscuit. dearly loved RIP 28.10.08
|
|
Rank: Advanced Member
Groups: Member
Joined: 6/1/2006
Posts: 4,065
Location: Dublin Ireland
|
I still can't understand how the under carriage got to that angle if it tipped when booming up,surely if it was ever so slightly boom heavy,on the balance point,its most vulnerable time is when the boom is coming up the first few feet,if it tipped then the undercarriage would only be a few degrees off the ground,sending the boom tip back to the ground and it would all stop,as the boom goes past horizontal the centre of gravity moves back towards the centre of mass,
I wonder if it was a structural failure in something,tipping forward like it did you can see ballast weights this side of the crane but there are also 3 visible weights on the ground behind,these could never fall if the crane was in its normal position or even if the farthest crawler was a few feet off the ground,perhaps these 3 plus more we can't see sat on the counter weight tray?
We can't see in the pic but does anyone know if this has alot of luffer on? if any? maybe the operator fancied doing multiple movements in one go,with main boom boomed up,then maybe hoisting up and out the luffer pushing the centre of gravity out from the centre of mass,while slewing??
Why is "phonetically" spelt with a "ph"?
... It's better to be silent and thought a fool, then to speak up and remove all doubt
The complex of Newgrange was originally built between c. 3100 and 2900 BC,[2] meaning that it's aproximately 5,000 years old. According to Carbon-14 dates,[3] it is more than 500 years older than the Great Pyramid of Giza in Egypt, and predates Stonehenge by about 1,000 years.
|
|
Rank: Advanced Member
Groups: Member
Joined: 4/11/2008
Posts: 1,605
Location: North Wales
|
Jibtickler has hit the nail on the head, as advanced as the these machines are it is almost always human error that brings them down. This machine had no way of knowing how much weight is on the tray, it is the responsibility of the operator to tell the computer how much has been placed in it, if he tells it there is 150t on it and there is only 50t then obviously it will allow the boom to be raised. This works the same with my crane, and at the moment it is one of the most advanced crane control systems in the world, I carry 28.2t on board the crane with the capability to add another 18.6t. If I add that but do not tell the computer it is not so much a issue unless i'm working at extreem close radius on half riggers with a short boom where the crane would been dangerously back heavy. If I do the opposite though it is far more dangerous, tell the computer there is 46.8t on the back when there is really 28.2 the crane will allow the lifting duties of the larger ballast when in reality the crane is a lot lighter on the back.
Now I know the next argument, why not have a load cell on the ballast, similar to what weights the weights the crane is lifting, this will obviously take human error out of the equation. However your then leading down a road of mechanical error.....what if that load cell gives a false reading, and those that have working with cranes will know that they are very complicated bits of kit and can be quite prone to electrical and mechanical failure. If that load cell tells the computer it is heavier than it is then the operator will not know. I tell everyone now that the best way to see how much ballast is on the crane is to get out and count it, physically count the weight and then tell the computer how much is on it, check and double check because as the picture above shows.....its quite important.
Sorry to go on but......one of the other reasons for cranes tipping over is the footprint, not so much of a issue with crawler cranes but with mobiles it is more of a reason for cranes falling over than ballast. The outriggers or sliding beams are retracted for road travel and then put to pacific set lengths depending on the duty charts of the crane. Most mobiles this is either half rigged (beams set half way out the crane) or fully rigged (obviously all the way). Some newer cranes, and smaller cranes will have more, mine has 3/4 rigged duties and city class cranes have straight down duties (beams retracted and jacks straight under the crane). The crane has no way of knowing how far these beams have been set, it is up the the operator to tell it. I know that liebherr have developed a system called sliding beam monitoring which will tell the computer how much the outriggers have been extended, this could be a good thing but in my mind theres no substitute for getting out and actually looking.
Back to the picture, I seen these pictures a while back and yes it frightens the hell out of me, if the operator was indeed in the cab we know the out come...however it is general consensus that the operator did indeed escape the cab before the counterweight came down on it. I certainly hope so!
Gaz
|
|
Rank: Advanced Member
Groups: Member
Joined: 6/7/2008
Posts: 1,560
Location: Waterford, Ireland
|
I dont think graham meant 'how did the computer allow the boom to be raised', its more a question of how did the crane actually physically tip over while raising the boom as surely if it was going to happen it would have happened when the boom was initially raised a few feet off the ground and not when it was high up in the air which looks to be the case judging by the angle of the crane in the picture. The closer the jib would get to vertical the more stable the crane would become and it was obviously raised pretty high when the crane went over judging by the angle of the crane. I wonder if it went over when the boom was being lowered down to de-rig as opposed to when it was being raised up?
Noel.
|
|
Rank: Advanced Member
Groups: Member
Joined: 4/11/2008
Posts: 1,605
Location: North Wales
|
Homer wrote:I dont think graham meant 'how did the computer allow the boom to be raised', its more a question of how did the crane actually physically tip over while raising the boom Sorry mate, I was writing my post while Granham replied so did not read his imput. I understand what he's saying but these things are not always black and white. We know that the crane went over due to not enough weight on the tray while the boom was being raised. I've got some detailed pictures of this accident and the length of the boom was massive, you cannot see that in this picture. The guy who is in charge of rigging our crawlers got a email shortly after this accident briefly explaining what happened so as to not the same mistake be made again. When booming up a crane like this the operator would have started very slowly as the pendent lines pulled tight and began to take the weight of the boom. The boom itself would have bent, or 'negative deflected' a long way before it came of the ground. There was a fixed fly at the end of the crane that run in line with the boom while on the ground while rigging. while the boom was raised the end of that fly stayed on the floor while the offset was put on, once the pendant line on that pulled tight the end of the fly would have raised. At this point the boom would already be at a great angle, with the weight of the fly only just adding to the weight of the boom, add to this then a 5t hook block, that is still yet to come off the deck....once this is reeved and the raised the boom goes yet higher with the full weight of all it is asked to lift only just coming onto the crane. This was the point the crane fell....with the boom at a 25-30 degree angle in my opinion. I'm not so good at explaining in writing sorry but i've seen some amazing boom lengths rigged and raised and what has happened here makes perfect sense....you guys can see only 1 picture....there is a lot more to this accident than this 1 picture shows. Gaz
|
|
Rank: Member
Groups: Member
Joined: 7/19/2006
Posts: 65
Location: Archbold, OH
|
My bet since we can't see the whole crane is that it has a luffing jib on it and it was not being boomed down correctly, and didn't have the proper amount of counterweight on the hanging ballast tray. That is the only way I could see the main boom being at that high of an angle and the crane tipping over.
Jeremy Kinsman Big Iron Farms www.bigironfarms.talkspot.comI.U.O.E Local 18 and proud of it!
|
|
Rank: Advanced Member
Groups: Member
Joined: 4/11/2008
Posts: 1,605
Location: North Wales
|
Big_Iron_Farms wrote:My bet since we can't see the whole crane is that it has a luffing jib on it and it was not being boomed down correctly No luffing jib, just a offset heavy boom tip for wind farms. Look at the main boom back stops, it looks in the picture that the main boom was at a high angle when it went over, this is deceiving, as the crane has fell the back mast has continued to pull the crane up after the main boom had hit the ground making the crane look like the main boom was at a higher angle than it was, the crane tipped while is was at a lower angle. Gaz
|
|
Rank: Advanced Member
Groups: Member
Joined: 6/5/2007
Posts: 2,760
Location: Sarasota, Florida, USA
|
I'm with Gaz on his explanation of what happened. Thanks Gaz it really explained it to me.
I also noticed, on the right side of the picture looks to be an additional counter weight tray with nothing on ithanging next to the boom.
The counter weights on the ground appear to be from the crane mounted tray only.
It would be speculation on my part but appears they tried raising the boom with minimal counter weight before any operations took place. Otherwise there would have been weights on the back tray when it came around.
Again Gaz thanks for your description, it was very helpful even for modeling standpoints!!
Dain
I'm a kid at heart, so I will play with any model construction vehicle from 1:87 scale to 1:1 scale!!!!
Age is a state of time NOT a state of mind!!
|
|
Rank: Advanced Member
Groups: Member
Joined: 6/7/2008
Posts: 1,560
Location: Waterford, Ireland
|
Gaz wrote:Homer wrote:I dont think graham meant 'how did the computer allow the boom to be raised', its more a question of how did the crane actually physically tip over while raising the boom Sorry mate, I was writing my post while Granham replied so did not read his imput. I understand what he's saying but these things are not always black and white. We know that the crane went over due to not enough weight on the tray while the boom was being raised. I've got some detailed pictures of this accident and the length of the boom was massive, you cannot see that in this picture. The guy who is in charge of rigging our crawlers got a email shortly after this accident briefly explaining what happened so as to not the same mistake be made again. When booming up a crane like this the operator would have started very slowly as the pendent lines pulled tight and began to take the weight of the boom. The boom itself would have bent, or 'negative deflected' a long way before it came of the ground. There was a fixed fly at the end of the crane that run in line with the boom while on the ground while rigging. while the boom was raised the end of that fly stayed on the floor while the offset was put on, once the pendant line on that pulled tight the end of the fly would have raised. At this point the boom would already be at a great angle, with the weight of the fly only just adding to the weight of the boom, add to this then a 5t hook block, that is still yet to come off the deck....once this is reeved and the raised the boom goes yet higher with the full weight of all it is asked to lift only just coming onto the crane. This was the point the crane fell....with the boom at a 25-30 degree angle in my opinion. I'm not so good at explaining in writing sorry but i've seen some amazing boom lengths rigged and raised and what has happened here makes perfect sense....you guys can see only 1 picture....there is a lot more to this accident than this 1 picture shows. Gaz Ah, that makes more sense alright Gaz.
Noel.
|
|
|
Guest |
