A tower crane went over today in NY, NY while adding more sections to raise it. As I was looking at the news on TV the site looked familuar. Where the crane cabin landed in the only empty lot on that block, I was there on This Monday that just passed looking at the site to bid the rock removal.
Is this the same one? http://www.newsday.com/news/local/wire/newyork/ny-bc-ny--craneaccident0315mar15,0,100282.story
Yes
wow, what a mess.
Maybe somebody familiar with tower cranes can comment here. How many places would such a crane typically be tied to the building, and would the loss of just one allow a catastrophic failure like this? Uhhh...I'd have thought dropping a piece of steel 19 stories anywhere at all would be a bad thing.... :beatsme
Was just reading the Post---says a retired contractor told the NYC Building Dep't. a couple days ago that he knew that crane was not correctly secured to the building.They blew him off and now this happens.Stupid loss of at least 4 lives,probably more still to be found.My Dad used to run cranes in the city--he came home earlier than usual a couple times because the boss told him to make an unsafe pick and he refused.Sounds like there's still stupid ,corruption,or both still rampant in the rotten apple.
Jacking I haven't seen any pics, only what I've read via the news link. When they talk of moving the crane to enable work on another floor, I am thinking that they mean they were jacking it up to put another section in. ( often done at weekend when crane is not required for lifts ) Pretty standard stuff in the UK and I assume ( never assume :Banghead) same world wide, BUT, we have had a spate of tower crane collapses over the past few years and problems seem to occure during this operation. If they were in the proccess of jacking, then the crane would have been at its most vunerable as its main tower could have had bolts loose or even removed. If something heavy enough to shear a wall anchor got dropped ( as it seems it did ) :thumbdown.
I feel this was a foundation failure ,again.I am looking at getting in to the tower crane world of work and i will get back here soon but i think the city would of had to approve the foundation. :new user
Welcome to Heavy Equipment Forums boomupkelly! :drinkup
They were jacking it and the collar they were adding fell, and then in turn took out all the ties to the building.
i am aware the top collar fell,(straps broke) and took other 2 out,but,most cranes have a large cement footer maybe 30by30by5foot,this crane weighs 150 ton.i thought collars were for added stability,not only stability.
inspection? First, havin re read this,:umno I apologise to Nac, who states in the original post that they were in fact jacking to fit another section :notworthy As to the size of the base :beatsme way out of my field I'm afraid, but must have been to an accepted design :cool2 I would love to know who was in charge of the daily inspection of the lifting gear ( UK specification ) as it would seem to me he / she has a major question to answer. I wont make any smart comments about it being OK for one more lift, we will replace it on Monday when the stores reopen. by me. ( haven't sussed how to enter different quotes in same post) If they were in the proccess of jacking, then the crane would have been at its most vunerable as its main tower could have had bolts loose or even removed. If something heavy enough to shear a wall anchor got dropped ( as it seems it did ) What do you call the top collar? are you refering to the next wall tie?
Cranes & Derricks in NYC Too early to determine what the actual cause is, only can speculate as to what happened, could have been as simple as the rigging used to secure the collar failing and then the domino effect after. I've read here on/off, have a heavy commercial construction background, most of it working in Manhattan and other borroughs in addition to having been an equipment operator in NJ prior to that. I was at the senior project manager level when I left the business, having worked my way up the ranks from the bottom. Maybe you are familiar with the procedures in NYC for crane installations , but I can shed some light on this if not. I have done quite a bit of work with cranes, mostly hydraulic rough terrain types up to 300 ton, have been on 2 sites with Cranes Inc big 500 ton hyd, + some crawlers on derricks and tower cranes on several other sites. Typically, a project manager representing either the sub contractor, like the steel erector or concrete sub, will size up and own the crane for the job. Sometimes the Const Mgr./General Contractor does it, depends on how the job is set up but can be a real pain when you have to schedule picks from a crane that is provided by the CM/GC or a sub. NO matter who does it, they have to use a licensed professional engineer to design the installation and confirm the size and configuration, and in this case, I do know the particular designer of this installation quite well, as well as the outfit that leased the crane who were also always a pleasure to deal with in my experience having done numerous installations in the past with both. There were only a few people in NYC that did the "expediting" or crane permit filings with the city agencies, specializing in this area and maintaining contacts, kind of niche business in that respect. The licensed professional engineer in this case, would have filed an application with the City of New York Dept. of Buildings, and City of NY D.O.T. for approval by their plan examiners The permit is issued and the associated paper work is copied to all appropriate parties including the operating engineer on the crane. The city does not like hydraulic cranes placed on the streets, like the mobile rough terrain types, and are hesitant to approve them for use and issue permits in many situations, they have to close lanes for the outriggers, restrict traffic, pedestrians, there are just a myriad of reasons why, some including safety as well as previous accidents. They seem to prefer a crane installation to be within the footprint of the building or within the sites work limits, inside the fence, so a tower crane would usually be more easily approved, as it is close to or within the new buildings footprint, no impact to traffic, still have to flag and stop pedestrians if hoisting over a walkway even if it has a sidewalk bridge protective structure installed over the walkway. Cranes & Derricks may elect to inspect and do show up to inspect an installation, with hydraulic types placed on the street, outrigger dunnage is a big item to inspect. The operator will also review the drawings and technical information to make sure everything is in order, have to remember these guys do not appreciate putting their city of new york crane licenses and other certifications at risk, all the operators I've had on my payroll were copied on the information as soon as the crane arrived, or they arrived on site for the installation. None that I have known would take chances there for any reason. There is a catch to this, they certainly can't see the condition of the rigging being used when in the house above, and if someone uses something compromised, the operator just won't be able to see it from one of these rigs, they rely on and trust the people below doing the rigging. I have seen many times where things that were rigged, were very risky and needed to be corrected. Slings, choker cables, etc. have to be in 100% condition, yet a contractor will use these items if well worn as I have often seen unless someone stops them. I think it is important to realize that the operator of this crane along with his riggers would have been familiar, or should have been familiar with the details of the installation, per the drawings created by the engineer, and approved by the city agencies, it is hard to believe that either the operator, riggers and the engineer who designed the installation would have missed an important detail like improper or missing connections to the superstructure, or that the crane was installed with deficient connections to the building violating the drawings, this engineer would have inspected all of this on site, he is a very hands on, field orientated person, as are his people. I don't see that happening, unless someone did something unbeknownst, but even the operator should have been attentive to something like this if it were to occur. The seemingly dumbest things can and will occur, in early Sept. '99, the hurricane Floyd came through the city, on Sixth avenue, 23rd-26th I forget now, but Turner was doing a typical reinforced concrete, 30 story job, where they had a 777 or 4100 Manitowoc crawler on a derrick, tower type mast with luffing jib, (terminology is getting rusty for, may need correction), to make the reach needed, building was close to or topped off. They folded up the crane and secured it, the storm passed, the operator ended up trying to unfold the boom/luffing jib, with the restraints still in place, it pulled the entire tower/mast & boom over backwards, I heard the crash from my job site and ran over a few blocks, it killed a local 608 carpenter. They lashed it down, but never heard as to why they were not released before he powered up, or what happened, seemed foolish, but hard to say without being involved. Every installation in the city is probably going to be heavily scrutinized now. I also think after the investigation, the procedures for erecting, climbing and rigging this type of crane will be reviewed. There also master rigger licenses granted to people who have to pass a detailed test, NYC is extremely stringent on these things, crane installations and rigging are taken very seriously, D.O.B. cranes and derricks, D.O.T. and the B.E.S.T. squad are the leading agencies for safety. This is a typical reinforced concrete residential structure going up, tower is on a foundation and tied off the to the building. The risk when climbing and adding sections, is certainly dependent on the rigging holding the collar, and there was no back up for what occured. I'm curious about the foundation, but obviously this design was not for a stand alone configuration or it too was compromised by what occured. Under the streets or below grade you can have all kinds of conflicts and things to deal with, if you are close to a subway, you may also need MTA and Port Authority approvals, so maybe a deep foundation for the crane was not possible here and it relied more on the building's superstructure, lot of possibilities to consider in the design, working in Manhattan can be full of challenges to say the least. 12,000 lbs. falling from 10-20 stories could have not only sheared the connections to the building, but also destroyed the foundation and connections even if it was strong enough for stand alone at the height it was. Most of these are stand alone until the building reaches some height then they attach to the building, might have been engineered like that, after a certain tower height, there will be enough superstructure erected, with 28 days allowed for the concrete to cure allowing for connections to the tower to be made that would allow it's height to be then raised. We worked with one set up on cantilevered dunnage beams off the 10th floor of a bldg., in '03 at 640 5th avenue across from St Patricks cathedral, that was a real unique set up, have a few photos of that one. I think that an alternate detail for installing additional temporary connections to the tower from the superstructure, which would keep the tower from moving or falling in the event the rigging failed on a pick like this while raising the tower to a new height and installing the required collars, will be considered for a requirement. The back up connections for tying back the tower would have to be pre-coordinated into the structural design of the building, and allow for no conflicts with the tower raising and other procedures. It is evident that there is no back up or secondary connections used currently after seeing an event like this, very possible for some manatory changes in procedures, structural design, approval and inspection, of this kind of equipment by city agencies. One thing about NYC projects, all have compressed schedules and are run by super motivated project managers, executives, and unrelenting owners who just keep upping the anty with pushing these compressed schedules, things get too tight and they push and push production to the max at all times. Usually don't like interupting that 3 day per floor cycle on these concrete jobs. This high paced environment can be a breeding ground for safety issues, they had a lot of unrelated violations already, but are typical for this type of job. Even with that in mind, the crane installation should not have violated the design by the engineer and what was approved on the permit. I strongly suspect the rigging used and procedures followed during the pick will be the focus of the investigation. http://www.nytimes.com/2008/03/17/n...1221364800&WT.srch=1&excamp=GGGNcranecollapse
See if this thread helps any: Quoting Other Posts
Welcome to Heavy Equipment Forums Billy D7 4T! :drinkup
There was a report on the news tonight that the City inspector assigned to this crane has been arrested for falsifying records. A complaint had been filed by a citizen a few days earlier who noticed bolts missing from the base of the crane. The inspector apparently signed off on the crane without actually having visited the site and making the inspection. There was no mention of whether these missing bolts would have had anything to do with the accident.
Here's the story on Yahoo News.
City of NY D.O.B. people There are some seemingly strange people in City of New York D.O.B., some of the inspectors I've had were nothing less than bizarre, some try to intimidate, others just a little odd, one plumbing inspector who did a rough in under the slab inspection before a concrete pour was a also a self proclaimed self healer with published books, he was more interested talking about things like how to cure Lyme disease by injecting doses of ones urine. Well, a little strange, but very friendly guy, we passed the inspection, never forgot that guy, and a few others from that department. I really enjoyed the tough guy image projecting, badge waving irishman who demanded to see the stamped, perforated approved d.o.b. drawings during the excavation foundation work phase on the same job, he demanded they be kept on site in the hole per Code requirements, and you do have to have this original set on site by code, somewhere, but you don't want lose or let this set get damaged for any reasonm they should be kept locked up, work off of duplicates. My office was right across the street, he still wrote us a violation, he's barking at me to come up out of the hole, I made him wait as I was busy, like who the heck are you, and where am I supposed to keep this original set, in a weatherproof, watertight gangbox with your lock on it, we're not even out of the hole yet, across the street was not good enough, never forgot him and he showed up again at the end for final cert. of occupancy inspections, was much more polite and easy to work with, maybe standing up to him worked, never was much for people like that and would tell them to pound salt, badge or no badge. http://users.erols.com/martinlara/ Cranes & Derricks people were usually serious, if this guy rubber stamped an inspection like that, hard to believe, what a jerk, there has been a lot of corruption in the past. I was always warned these inspectors can and will be wired, they cleaned house in the past and if you are dumb enough to try and buy one of them, sooner or later, one of the bad ones caught already and has agreed to be wired may come your way and you will go down. There are a lot of people in NYC that are activists for all kinds of things, you damage a tree they'll chase you down, call the parks dept police, many times there are former construction trades, familiar with things like tower cranes, job safety and they will file complaints, it's probably what generated an order to inspect the crane on site, all he had to do is show up, look at the approved permit with drawings, check the details on site and make sure they match what is on the drawing, probably a friday and wanted to leave early, rubber stamped it.
quotes Thanks for the link Countryboy, I'll have a play in the test are.
Found two interesting articles on ENR about this accident: Crane Collapse Crane Examiner Charged Sounds like the examiner didn't have anything to do really with the collapse (I think. They are still busting him which is good IMO). Appears that they were getting ready to add another brace to the structure and the collar that attaches the brace to the crane fell and that took out the lower braces. Interesting.
Enr - Ny Crane & D.o.b. It sounds like a master rigger was on site, I was wondering about what NY CRANE's arrangement was with the C.M./G.C., being leased hopefully will afford them some protection, as they are kind of indeminfied from means and methods, or should be if the G.C. had their own 14&15 O.E. on site. Have to wonder if there was a Master Mech. on site too, standby, like a shop steward, but many of them are highly experienced and would be another set of eyes to spot a problem. The B.E.S.T. squad, a division or dept. of D.O.B. was on site too, with high rises, you can't leave materials on the decks near or close to the edges, I used to tie off all our materials to columns when faced with high winds, so they were given a stop work order on that, typical violation, also hints at the site management, if D.O.B. inspected the building, high wind warnings and there were violations on that, nothing to do with the crane though. I agree with Jimmy Lomma, don't like nylon straps at all, the condition of them can be compromised, physical damage, and or even UV light weathering them, often times I used to have to go to a supplier on the lower west side, forget the outfit, they supply rigging, and get brand new slings, instructing my Ironworkers to use care with them and cut up any that are damaged. Abrasion and cuts to them was the #1 reason. 2 things come to mind, were the slings certified for the weights and the configurations used, choker, cradle or however they rigged the collar and were they defective when manufactured or compromised before or during use. I have always disliked the foreign manufacture of these items, we used to MFR quality rigging equipment, just look in old industrial catalogs, what criteria or reference standards do foreign manufacture adhere to and who checks it ??? I've seen these cranes installed and taken down many times, but don't recall the details of adding sections, it's always done off hours out of sequence of regular production work, the last place I want to be on a saturday is at work whenever possible, but as PM or super, running that job, you would have to be there and be right where the action was going on and you cannot be afraid to stop someone when you see something you think is wrong. That article states they usually set these collars in 3-4 picks, so I would imagine that each of the sections would attach to the tower at the specified point, to surround it, so when the last section goes on, it is also attached to the building and secures the crane as designed by the engineer. My concern with this would be that when the tower is raised and requires additional connections to the building via the collar(s), with the previous multiple pick sequence to place same and connect it, is the tower at risk until it is connected, or it's working load limits, radius reduced enough and the jib must stay closer to vertical or at the opposite angle for balance, etc. until the connections are made, meaning you must be very careful and work within the reduced limits, kind of like a hydraulic R.T. when on intermediate outriggers, you are limited by weight and pick radius. If that is the case, one would think that some temporary connections could or should be made 1st, to secure the tower, prior to the sequence of placing the collar in pieces or as a whole, like they were doing at this site. It appears obvious that if there were some tiebacks above the collar, the tower could have been secured above the last collar, and also at the foundation. With this scenario, you wonder if both those connections would have been enough to keep it from getting motion, the counterweight and subsequent motion sure would have placed some serious moment arm type forces on it, once it gets moving. The key to it would be to have the tower secured enough to prevent it from getting motion in the first place. If what occurred at this site happens, and a collar falls, say the crane is compromised, but still tied off, it would seem to be a much better outcome, even if it had to be disassembled and re-erected, compared to what happened at this site, might have prevented what happened. Out of respect for all parties involved, it is unfair for me to really say, just speculation from a friend in the industry, this is a very tragic event. I'm sure the temp connections would be a cost item, would have to design something that you could attach to the building as designed, coordinated with the structural drawings and engineer of record, problem being the last deck poured would not be 28 days cured in a 3 day cycle, so you would have to go as many floors lower or find an alternate detail, per the engineer, it is going to be a cost item especially if the superstructure is not going to be easily attached too for some reason should be coordinated into the structural drawings at the design stage. Some kind of back up connections is really something to consider. I'm sure a lot of buildings have been put up without any, similar to this one, but all it takes is 1 time, and we have that on this site, it is going to be the cause of change. It sounds as if the crew wanted to place it in one pick, saving time, but if it does turn out to be the nylon slings, it is kind of clear as to the mistake made. That piece weighed 12,000 lbs, or 6 ton, according to the reports, no way would I be using nylon slings, too heavy to chance, a 4 way spreader, wire rope off of a ring to the headache ball hook, there is just no way when you compare safe working loads of these 2 materials, that nylon is even worth consideration for a pick like this. 5/8" wire rope, 4 lift points to spread out the live load, I'm sure just one would would hold that weight just from memory. I have used them for material picks up to 2 tons, but beyond that, no way.
Tr-1 One thing I have not seen mentioned in any reports is who was signatory on the TR-1, ( technical responsibility report - city of new york dept of buildings form). I have been signatory to many of those, and one thing is for sure, you had best be on site anytime that crane is hoisting, start to finish. This person would usually be from the C.M./G.C. as they leased the crane, the engineer who filed the application for the permit would have this person sign before the application is filed, as the responsible person to be on site supervising the crane operations, it's usually a superintendent, but could be a project manager or another qualified person. ENR mentions NY Crane as the supplier of the Favco crane, (they had bought quite a few of those) and that a master rigger from their company would be present during this operation, probably to observe, but I don't think that person would be signatory to the TR-1. I would assume that NY Crane indeminfied themselves through the lease agreement. There are some scenarios to consider, like I mentioned, the people involved here are very professional and heavily experienced, and aside from the victims and their families whom are suffering, my thoughts are also with NY Crane, the union locals and the engineer who filed this job as this is also a terrible situation for them as well. In the past, I don't believe the person on the TR-1 was required to have any certifications, but can still be approved, though the engineer filing would not put you on that TR-1 if you had no experience. I never had any certifications, nor did any of my Ironworkers, we could get the permit for a hydraulic, set up an operation, close streets and do whatever necessary prior to the hoisting operations, rigging items to be placed as you see fit, based on your knowledge and experience, this leaves the door open for bad practice and someone grabbing a defective set of slings for use from the back of a pick up truck or bottom of a gangbox without much consideration to their condition. I cannot tell you how important it is for the TR-1 responsible party to know what they are doing and to correct anything that is wrong, sometimes trades people don't have the expertise or take chances, I've seen it numerous times, even with my own crews, had I not been there........ don't want to think about that. I can see where this is going, a licensed master rigger is going to be much more involved on site or the trades, foremen, supers even P.M.'s may be required to have some certifications or get the master riggers license. Having been signatory to these forms on site, I cannot imagine what your liability would be in a case like this, these sites are fast paced and many have difficult situations to lift and place building components, I know the stress from those kind of operations and have always wondered what my liability would be being signatory to something like that TR-1.