Sunday, July 18, 2010

July 10th, 2010

Ulyanovsk Russia A Self-Erecting Tower crane on rails collapsed killing the crane operator. There is a short video that really doesn't add much to understanding the accident unless you speak Russian. I don't know what else I can add to explaining these accidents in Russia given that I cannot find more info on this accident. I think that I've hammered these rigs enough in the last week doing the Russian searches.

Original Article

крах башенный кран,  аварии башенного крана

September 28th, 2009

Tver Russian - A Self-Erecting Tower Crane collapsed after running off it's rails. The collapse didn't actually happen until the next day, and so fortunately no one was injured. This is not a rare occurrence in Russia. Cranes seem to run off the rails on a regular basis. So why and how is what comes to mind for me.

Examples of cranes running off the rails.. St Petersburg 2007, Minsk 2008, and I've ran across another one that ran off the rails, but they successfully got it back onto the rails so I didn't put up a post on it. In St Petersburg, the rails were removed prior to dismantling the crane. They just got ahead of themselves and then the operator ran off the end. In Minsk the brakes failed. But more importantly, where are the stops on these rails? Why is it that these cranes are able to run off the rails? They are supposed to be level, have a mechanical shutoff prior to the stops... oh, and have functioning brakes to safely stop the crane.

In this Tver case, the brakes were not working on the traveler. What I found really interesting in the article is this quote, "Tower Crane, who worked at the construction site, was built in 1991, the term of such equipment is 10 years. Accordingly, the life of the crane expired 8 years ago." I don't know where the writer is getting the information and he notes that with maintenance the life can be extended. Do we have maintenance records? Was it maintained? Was this the first time that the brakes malfunctioned?
Original Article

Russia is clearly not respecting any standards set by manufacturers. You can have the rules in place, but if no one enforces them due to open corruption, what is the point o having regulations? I have family in Eastern Europe, and they can't believe how business is done here. There needs to be a fundamental change before these accidents will come to an end over there. When government officials are wearing $300k watches, we can easily see what the real source of accidents like this are.

крах башенный кран, аварии башенного крана

Friday, July 16, 2010

July 2nd, 2010

Amstetten Austria A crane operator was returning to work from having taken lunch. The operator tripped and lost control of the remote control to the crane. The crane apparently had a load on the hook. The control of the crane was knocked into hoisting down quickly. The load came down and struck another worker killing them.

A couple of things. If there was a load on the hook and this isn't a translation or reporter issue, then why is the operator not with the crane? We should never be leaving a load on the hook and walking away from the crane. Secondly, why is the remote activated if the remote is not attached to us? If the remote is not activated, it could fall anywhere and this won't be an issue. Third, was the control set up to auto zero. Most modern cranes cease to function when the controller is released. It's the standard that we have by law. I concede that it's possible for the remote to land on sometime which held the function on, we just want to be sure that our controls do auto zero and this is a prime example of why.

I see a series of question all that may have led to this accident occurring. The intent sounds like it was clearly an accident. I'm just thinking of the things that should have been in practice to prevent this.

June 22nd, 2010

Passau Germany A Self-Erecting Tower crane collapsed onto a farm roof in Passau. The operator was only slightly injured due to some falling tiles. He was operating the crane remotely and so he was not subjected to the falling of the crane.

The crane was being used on a farm to build a silo. While it is dry in the summer months in Germany, the soils may not be as firm as required. It would be important to have out outrigger pads as well considering the soft fertile soil often found on farms.

Have you noticed that there were three accidents on June 22nd and 4 in the last two days? Are we back to our old bad habits? Are we forgetting about crane safety because we haven't seen a "major" accident in a while? Make sure that you are keeping a close eye on your cranes and the practices surrounding them. Just because work is slow and you need the job, doesn't mean that we should be allowing unsafe conditions to go on.

Turmdrehkran Unfall

July 15th, 2010

Wels Austria. A man operating or signalling a tower crane was knocked from the scaffolding he was on by the crane. He fell about 50 feet. When help arrived he was still conscious and speaking. An hour and a half later he died of his injuries.

Anyone can make a mistake and get themselves in a pinch. More commonly though, guys are put on the radio to signal cranes without any real training. This is a problem in our industry. I'm going to talk about a few signalling concepts. If you know how to stop a load from swinging without touching it (catching the load), then this isn't for you. This is for the guys that don't know about that concept. If you don't know this concept, you should. It will make you money, make the operator happy, and maybe save your life. Not knowing this concept may be what killed the man in this story.

I'm going to run with the assumption that he was signalling the crane. Maybe via radio in the blind. Something that I do besides crane inspections is Signal Person Certifications. One of my clients needed it done on site for just one job so I stepped up to the plate. I came up with a game plan to have guys rig various items. I put in sharp items with choices of rigging, regular items, loose, etc. The person would be asked to choose the best way to rig then I would have them proficiently signal the crane. Part of that is making someone signal in the blind in tight areas. We were looking for "qualified" people to signal the crane. Not the minimum, but guys that would be able to get the job done and done safely.

Guy after guy with 20 years of experience could only pass with minimal proficiency. For me it was an indication that we aren't doing enough to teach in this area. Our leadership in many places aren't any good at signalling the crane so they assume that it's easy. Sure, if you do a poor job, it's super easy. In fact signalling a crane is not that hard. But there are concepts such as catching the load that are lost on many. Testers were coming down into a stairwell with good sized pieces when I'd have to call off the crane operations and ask them to "catch" the load (prevent it from swinging too much). The common response was, "But the tag line isn't long enough." Sigh.

Swinging loads are prevented by good operators or signal people. If you haven't ever seen it, or don't know what I'm talking about, go get a fishing pole and put a string and a weight on it. Now swing around like a crane. When you stop, the load continues to drift out because it's a rope with a weight on it. So you can do three things to prevent that. Slow down the swing prior to getting to where you want to stop. In Seattle I would say "easy swing" and the load will drift out ahead and to the side of the boom due to momentum. Then I watch until the boom and the load are just about in line with one another and then say "swing". By the time the boom fully stops I should be directly over the load and have it in control. If you have lost control and need to get it back under control, you wait until the load passes under the center of the boom then call for swing in the same direction until you are dead center over it, then stop the swing. As an operator, what I would do is get the swing or boom moving slowly, then pick up the pace of the movement as the load swinging got close to the center. That way I would stay over the load and it didn't swing. As I came to a stop on the swing I would counter swing the crane getting the load drifting out (reasonably of course) and allow the momentum of the crane to move over the load at about the same pace then stop the swing when you are over it. We all have slightly different techniques, but the principles are the same. It's all very simple, but the timing and practice with your operator takes time. Talk about your signalling. Ask what they like and don't like about it. Some operators want to be left alone. Other's want every signal there is. When you operate with a good iron working crew the day's fly by because you are doing very little thinking, just pulling the levers as told and keeping track of the three or four functions going on at a time. Get out that fishing pole and get the concept down. Then go put it into practice. you can also use that fishing pole to learn about boom deflection. That's another concept that you need to know if you are signalling cranes.

July 16th, 2010

Regensburg Germany, A Self-Erecting Liebherr K Crane tipped slightly injuring one worker. The crane tipped at the base and does not appear to have any structural causes in the super structure. From the translation of the story I'm not clear as to whether or not it was caused by overload but it does sound as if they were bucketing concrete. As a cause of Self-Erectors going over, this seems common. Does anyone set moment limits anymore? Check them with a known weight and tape if need be? I would hope that's standard practice.

The base of the crane is only seen in a video from this article. Hitting the pause only gives a better view of the base and it's still not a good view to see if there was a failure there. It sounds as if the crane was placed up on concrete, so the only question there is was there enough padding to spread the load if it were thin concrete?

There was a fourth accident in the last two days that I am now trying to hunt down. Vigilance gentlemen... don't get lulled back to easy street because the market has slowed down .

Turmdrehkran Unfall

July 15th, 2010

Laussane Switzerland, A Self-Erecting Tower Crane collapsed today. No one was reported as injured. One driver was startled as his car was just barely struck on the mirror. He was very close to being involved in the accident. No operator was noted as being injured.

Looking at the pictures, I'm a little surprised at what I see. I see a set of pins missing on the rear of the crane at the tower. Is it possible that the crane was erected without these pins? When I zoom in on the picture I don't see any damage to the dowel coming out of the bottom tower or the pocket on the upper tower. Could it be that they were dismantling and they moved the tower up only to find that the pins weren't in at all? Could it be that they were erecting for this site a second time and the pins were forgotten (reported as a 9 AM accident)? or possibly when they slackened the luffing rope to let down the boom to touch the tip to the ground it got enough movement that it just fell forward and has been like this since the crane was erected? This last scenario is the one that speaks to me since the job is enclosed.

This was a very lucky incident that the crane appears to have survived an entire job missing a set of tower pins and no one was killed. Don't get in a hurry and it never hurts to have someone double check your work. We all have made mistakes, but this one is easily avoidable.

The story online has many more pictures.

July 16th, 2010

Erlangen Germany A mobile crane tipped over backwards during what sounds to be a tower crane dismantle at a sewage treatment plant. The mobile crane operator was sent to the hospital be ambulance. The damage was already listed at 1.5 million dollars. 

The crane was said to have tipped over backwards. The picture doesn't quite show that, but appears to have been overloaded or had poor support under the outriggers as he was booming down to set the load down. What sometimes happens is a job is scaled (panned) out for where the crane needs to sit in order to make the pics off of the tower crane. If the person doing the scaling doesn't consider where the load must be set down as a factor, and the operator is willing to turn the key in order to get the work done, you may end up in this situation. 

To be fair to the Mobile Crane Operator, the pictures don't show the ground and the article doesn't talk about cause. It's quite possible that the ground he was sitting on was back fill and not compacted enough. He easily could have been given poor information as well which would point the finger at someone else. 

Turmdrehkran Unfall

January 31st, 2007

Omsk Russia A 20 meter tall tower crane fell. The female operator survived the crash with a broken leg and was taken to the hospital.

The collapse again happened from the base area of the crane. The mast is clearly laying down on the ground. The article notes that the cause is presumed to be overloading. So let's suggest that these cranes in Russia are dropping due to limit failures. Why are they not addressing that? The beauty of running a tower crane was always, either the crane can make the pick, or it can't. There is no turning the key to make things happen. If everything is working properly, you cannot over load a tower crane.

One of my favorite over load stories comes from my area. The story as it's been told to me is that a self erector was unable to hoist a pallet off the ground. So the solution was to load the crane with a fork lift, then pull the fork lift out from under the load. This is ill-advised. You have hoist and moment limits for a reason. In this case, the load was far enough out that it existed for stability reasons. Shortly after getting the forklift clear, the crane tipped and came crashing down. Now I know that this story has a lot of validity. But I can't even find it locally in the news or otherwise. How many of these are we missing? Have there been 400... 500 tower crane accidents in the last decade? Sadly we'll never have the accurate number so that we can address it methodically.

July 3rd, 2007

Veliky Novgorod Russia, A Large Self-Erecting Tower Crane collapsed killing one person, presumably the operator. The failure happened near the base of the crane. The article does not note any cause such as overloading or a cracked structure. 

We seem to have a theme here in Russia of cranes dropping like flies. You would think that they would seek out the most common causes and address it. Are the cranes being used properly? If not, how do you change that? Certify operators? Scare the industry into change? Require newer cranes? Require NDT testing? Government inspectors? You can't just have these cranes dropping every few months and not do anything about it. It's simply irresponsible and shows great deference to life. The article notes that a crane fell in the same town only 6 months prior. Something isn't working. 

June 22nd, 2010

Petropavlovsk-Kamchatsky Russia, A tower Crane collapsed during the dismantling killing three crane erectors and injuring the crane operator. The crane was on a cross base but the crane superstructure managed to rip away from the mast bending and destroying the mast. 

This article notes "refused Hydraulics". Looking at the video from this page it isn't clear as to whether or not the crane was a climber or not. There is no climber on the mast. When I watch the video I see blue and what appear to be platforms with the wreckage. The damage, the noting of hydraulics, and the platforms near the turntable lead me to believe that they over extended the climber for one reason or another. Many climbers don't leave a lot of margin for error. If the person operating it weren't paying attention or the valve stuck, this could be the result. I've never heard of a valve sticking on a climber, but I suppose anything is possible.  

March 27th, 2010

Saransk Russia,  A luffing tower crane tipped, hitting, and wrapping over the building it was working on. The article (video of the crane in article) notes that no one was injured in the accident. 6 cars were damaged and fortunately the cars at the intersection were all stopped.

The second article that I found also has video and can be translated in Google Chrome. This article notes that the crane "cracked almost at the base".

The overall design of the crane is very old. I hesitate to say that the crane is old because large luffing self erectors seems to be the norm in Russia. Inspection is also common in Russia according to some articles that I have been reading. For me it raises the question of usable life of cranes. If the crane was inspected like many of these older Russian cranes, how old does a crane get before you say it's reached it's design life and shouldn't be used anymore?

Thursday, July 15, 2010

November 11th, 2008

Moscow Russia A Tower Crane collapsed killing the 50 year old crane operator by throwing him out of the crane. Only one picture was found and it accompanies this post. There is a video as well on this page . I picked up that the crane is defective. Beyond that, I don't understand a word he's saying.

As you can see, There are plenty of Russian crane accidents. I'm only scratching the surface because the accident's don't stay up forever. The languages used are not my own and I can't even type the characters used unless I download software that may cause me grief, so I'm not interested. I've found old pictures of early self-erectors down that I can't find any info on. I found a German crane that appears to have dropped it's load on it's rails and it caused itself to go down in 1955. This is more of a derrick, and that's why I didn't put it up. I'm closing in on 200 posts with all but 10 to 15 of them being tower crane collapses. I hope that the message that this is something to take seriously daily is resonating.

May 25th, 2008

Minsk Russia A Tower Crane on Rails tipped over. The operator was not in the crane but running the crane remotely. Because of this, he was not injured by the accident.

The crane is older and it's assumed in the article that the traveler brakes failed. This would cause the crane to strike the end plates/buffers too hard and the collapse would be imminent. I heard of a new crane being ran with only one motor working on the traveler. The common position that "I'll make due." is not a wise decision. Most of the time you'll be just fine with that attitude. But the time that you aren't correct, you may be taking someone else's life in your hands, and you don't have that right. One of my favorite safety signs is "Just because you've been doing it for 20 years, doesn't mean that it won't kill you in 20 seconds." make sure that your equipment is operational. If it isn't, get new gear.

December 25th, 2009

Kirov Russia - A Self-Erecting Tower Crane collapsed during operation killing the operator. An adjacent 9 story hospital suffered some damage to the roof but no patients were injured.

The cause of the accident was being listed as under investigation. There was a second accident in Kirov in August of 2009 that I suppose I will have to go find.

April 29th, 2008

Kemerovo Russia - Tower Crane Collapsed killing the operator and injuring one other.

I don't recognize the type of crane at all. It almost appears as of the smaller tower sits inside of that base and is locked in there somehow. It does look like a clean break from this angle. I don't know what the mechanism is or what caused the accident so I'll just leave it at that. but don't forget to note how modern it is.

July 14th, 2009

Saratov Russia A mason was injured with a broken leg due to the collapse of a tower crane. The collapse was apparently caused by negligence (undisclosed) by the crane foreman. He even admitted to the negligence while being interviewed.

Looking at the picture, it appears that we have a clean separation between the turntable and mast. If this is the case, then it must have been a bolting issue. There are 8 bolts that torque up to 4300 ft lbs that and if they are not tightened properly with the counterweights over the corner being torqued or prior to going horizontal with the crane, then you will end up with bolts loosening up. If the others were pre-stressed correctly, it could be that one corner loosens up and gets a gap going unbeknown to the operator. If that gap grows, then the other have added stress and can eventually fail quickly in a zipper like fashion, one after the other.

What I used to do on bolted towers is note the position of the crane before I climbed. As I climbed I would put a hand on the bolts under compression due to the counterweights. Both corners on that side. Then when I climbed down, I would put the weights on the opposite side (wind allowing) and check the other side as I climbed down. This was a once a week operation at a minimum. It adds very little time to either climb and is simply common sense.

August 6th, 2007

St. Petersburg Russia A Self Erecting Tower Crane collapsed during a dismantling process. The 25 year old owner of the crane was on the top of the crane when the failure happened. He was thrown a reported 50 meters and was transported to the hospital with multiple injuries that were life threatening.

The cause of the accident wasn't official, but the story at the release of the article was that somone whom was charged with removing the lock nuts, removed the whole nut to some bolts. As you may expect, we appear to have human error as being the cause of this crane failing during a dismantle.

Wednesday, July 14, 2010

September 15, 2005

Dusseldorf Germany, A Self-Erecting Tower crane suffered a structural failure of the jib during the crane erection. No one was injured and only traffic as caused to jam afterwards.

Self-Erectors are difficult to properly inspect when they are not yet erected. Some of the points are hidden from inspection due to how they are folded. Most parts are readily visible, but occasionally, even a flashlight and a small mirror won't help. I walk the jibs of Self-Erectors after they are set up because of the in ability to inspect it all when folded. Occasionally other strange issues develop too that you won't notice until you walk one of these jibs. Given the size of the crane, it's a little exciting at times because merely walking on these jibs can cause a couple of feet of oscillation. Few things make you wonder about the integrity of the crane like walking a self- erector. Link to more photos

July 23rd, 2008

Cologne, Germany An older Self Erector was bucketing concrete when it suffered a structural failure of the boom. It came crashing down with the concrete bucket killing one man instantly and a second suffered injuries while jumping to safety. The crane is clearly an older model and it's appearance doesn't lend confidence even if it were erected. Link to photos of the crane

Did a limit fail? Did the boom rope break? did the Luffing Boom Hoist brake fail or not get locked off? Was there a structural failure? All questions unanswered... but it is an older crane with another mechanical or structural failure.

May 24th, 2009

Guro South Korea (outside of Seoul)- A Tower Crane collapsed during the crane erection process killing two and injuring one.

The crane is a small top slewing crane. It appears that the Counter Jib had been hung and either a counter weight or the main jib was next to be installed. The maximum over-turning moment on a crane is experienced when just the Counter Jib in in place during either the assembly or disassembly. There is a video of the scene here. If you'll notice the crane is mounted to a small frame. I'm not familiar with this type of frame, but it looks as if it sits on the ground and is presumably bolted down. Hopefully to large concrete anchors. The one side has sunk and unfortunately the pictures are clears whether this is bad soil or bad anchors.

타워 크레인 붕괴

March 31, 2006

Ulsan, South Korea - The Counter Jib of an old tower crane collapsed killing one 34 year old man as he fell 30 meters to his death.

The article notes that this occurred at Hyundai Heavy Industries on a site with a Goliath Crane. In seeking the city it appears that Ulsan is on the coast and has these large cranes as well as many luffing portal cranes and tower cranes.

These cranes that are erected for years at one site need to have the pendants and pins inspected as well as the rest of the crane. Pendants are terrifically strong, but can suffer from age and salty sea air just like anything else. In erecting and dismantling cranes in Hawaii, the sea air wreaked havoc on the cranes. There was a newer Liebherr 316 that had a tower top to cab pin virtually welded in place. Using 20 lb sledge hammers in good swinging positions, we couldn't move the pin. Eventually we used a beam rigged to the crane and a porta-power hydraulic ram. We bent the beam. We had enough capacity so we removed the tower top with the cab. Eventually back at the yard the pin had to be lanced which relieved enough tension to allow the pin to be driven out.

These ship yards with the old cranes should have someone in a Suspended Platform from a second crane giving a close review to the condition of the pendants and pins periodically over the years. This of course is in addition the minimally needed annual inspection.

If you've read my blog for a while, you know how I feel about older cranes. Here is an example of a older crane that suffered a Counter Jib failure. Age is certain to be a factor.

타워 크레인 붕괴

October 30th, 2008

Changwon South Korea, A tower crane suffered a wild collapse. The Outer Jib and Counter Jib both collapsed and were effectively hanging by their pendants. 1 was noted as killed and 3 were reported as injured.

The cause of the accident isn't clear in the report. From the translation it would appear that testing was occurring on the crane. I don't see any gap between the turntable and the mast so I don't imagine that it was climbing. I've certainly felt oscillation in climbers before that felt very bad for the crane. Bouncing bad enough to cause the pendants to slacken up. But since there doesn't appear to be a gap there, I wouldn't expect that to be the cause.

Was a keeper missing from a pin at the outer to inner jib connection? That could be violent enough to cause the counter jib to buckle. Was there a structural defect? The joints on the lower chords are welded on. It's a weld that is often ground down so smooth that it isn't visible. Most of the lower chord pins are under compression, most of the time. The joint adjacent to queens posts would have considerable shear added due to the down force of the pendants carrying the load. Certainly a weld is normally acceptable there, but what if there was a defect in that weld? It's a spot that we should be looking at during the pre-erection inspection.

타워 크레인 붕괴

Monday, July 12, 2010

July 10th, 2010

Nashville Tennessee - A crane operator suffered a stroke while operating the crane on Saturday. A firefighter climbed the crane and prepared the man for transport off the crane in a stretcher and harness. It sounds as if in this case there was a second taller tower crane on site which would have saved valuable time. The condition of the operator wasn't known.

There are a few things to look at to aid in saving operators who have medical emergencies on cranes. The ideal scenario is to have a package on the crane ready to go to save the operator. in a job box if you had a sheave that could quickly be mounted to a lacing (appropriate rigging), a rescue basket, a few extra universal harnesses, and sufficient rope, we could expedite rescues. rescuers wouldn't need to carry or prepare gear and climb the towers with it. There is a problem with this... many fire departments wouldn't use someone else's gear. We all know that just a few minutes can sometimes be the difference between life and death in some emergencies so if even we had the basket and harness ready to go, we'd be ahead of the game.

One company that addresses tower rescue with is Gravitec. I'm aware of Gravitec because they are somewhat local to me and they market well. They may have solutions that would allow you to come up with a rescue plan more detailed than simply "Call the Fire Department". Maybe your fire department would use this gear if it were present and partially set up prior to their arrival.

Another option is one that I'm affiliated with that would only apply in situations like this Nashville one where a second crane is present. Thats a Boscaro Rescue Platform. It's a man basket designed with an end door that opens like a ramp to allow easy ingress/egress of a stretcher. it also allows the medic to work on the patient while in transit if he were to need CPR or pressure to prevent bleeding. I could go on with more options that it can come with like O2 Tank mounts, etc. It's a crane based ambulance. This would prevent climb time and I don't know why any department would not use it. You can contact me for this product.

We have to plan ahead for these incidents. Most fire departments are capable of addressing these scenarios. But planning ahead and having the right equipment and plan in place can make the difference between life and death. These incidents happen. Pick up the phone and talk to the fire department during the crane planning phase. Find out what assistance will be helpful for them and what they will accept to save time.

Friday, July 9, 2010

April 8th, 2010

Busan Korea, a Liebherr Luffing tower crane suffered a collapse of the boom for reasons that are unclear in the article. the article notes, winds, striking other objects and other potential causes, but doesn't pin point a cause.

The crane was located about 400 feet up on the building that they were working on. Fortunately the boom landed on the building and didn't injure anyone. Also conveniently there was a second Luffing Tower crane at or on the same level that was able to service the repairs. The article in translation makes it appear that the boom was replaced and the crane was put back into service.

If the brake failed or the boom rope failed it's possible that no other damage occurred to the crane and with a new boom it would be safe to go back to work with some simple repairs.

타워 크레인 붕괴

June 17th, 2007

Chonnam Korea, An apparent climbing accident occurred on a tower crane that was only 20 meters high. Four people died and one was injured.

Watching a video on this link showed the turntable upside down with loose bolts with no nuts on them. As we've seen numerous times over and over, crews push up into the turntable then loosen bolts prior to installing the pins or bolts that connect the superstructure to the climber. I frankly don't understand it. Occasionally you'll have a hard pin to drive for a climb. Generally it's a 15 minute process for two guys. There are so many things to do in preparation for a climb that it's a non-issue. You have to prep the power chord. Get the towers lined up. Get tools on the climber. Get bolts or pins on the towers. Lower the "diving board or install the rail, or other system to handle the tower. There is no reason to skip this step but we can point to at least four of these accidents here on this site. And the bolts are even easier. Don't be a hero and "balance the crane on the climber. Dozens have died doing just that. It's not a freak accident if it just keeps happening.

타워 크레인 붕괴

May 29, 2007

Changwon City Korea, a tower crane collapsed falling onto iron work structure below. The article makes it sound as if the operator survived with back injuries. The cab stayed on the top portion of the crane as the crane broke at the cat head to the turntable connection.

The cause of the accident appears to be due to bolt failure. The question that comes to mind is what was the torque applied to the bolt?

What's even more confusing is that the article shows a tension control bolt (typical structural steel bolt, often a A325 bolt, sometimes called a Lejune bolt but that is a name brand like Cresent Wrench is actually an adjustable wrench.) The difficulty is that the translation services online are great tools, but sometimes some detail are lost. If this bolt shown was the one that failed, it's not the correct bolt for the application.

Also note that the date isn't something that I'm certain of. The date format of Korea isn't clear to me.

타워 크레인 붕괴

April 26th, 2002

Dusseldorf Germany I'm unsure about the location. The article notes the street name, but never mentions the city. A tower crane on a cross base fell over. fortunately the accident happened during lunch and so no one on the ground was injured. Additionally the operator was only in some mental shock. He did suffer some minor scrapes and bruising. The crane fell towards the up hill side with the counter jib striking the building first which slowed the progress of the fall. This is also part of what saved the life of Warren Yeakey, the tower crane operator in Bellevue Washington USA.

Looking at the overhead picture, it's not clear as to why the cross base failed. Did it have a structural failure? Did the ground give way? The ballast is present and the crane was not working at the time of failure so I'll assume that it wasn't a lack of ballast. One thing that I have experienced on a cross base is the ballast attempting to "walk" on the beams. If the ballast is not secured in place somehow, minor flexing in the horizontal beams can move the weights. you would think that it would be impossible, but it happens. Some of the older cranes don't have methods to lock the weights in place, and these are the ones that we really need to be aware of. Most late model cranes have recesses to prevent this walking of weights. If you had a crane that didn't have this, I'd want to mark the weights on the beams and strap them in place just for that warm and fuzzy feeling and as a best practice.

October 8th, 2004

Bellentre (Savoy) France - A self erecting tower crane collapsed due to Oscillation and not having the proper "locking devices". The crane and operator hadn't been properly reviewed. On some of the self erectors, the mast must be mechanically wedged or locked into place. On a Potain HDT 80 for example, it's a threaded large diameter bolt that physically pins the mast in place in the event of mechanical failure.

When the crane fell it killed 8 year old Lea Montez. I'm sharing the photo because sometimes a face is critical as to how important our safety procedures are. In China I know of two accidents that have killed children in school. We owe them our best protection.

The crane owner was charged for not having the crane properly inspected and for not making sure that the operator was certified. The crane owners son apparently did some operation of the crane in contravention to the law as he isn't licensed as a crane operator. In the end he was sentenced to 2 years in prison with 18 months suspended. The prosecutor was unrelenting in his speech, "The sole objective of Jean-Michel Pin is to cut back on everything. Involving a company specializing in the inspection of cranes would have cost 269.For you, life was worth so Lea, 269" (link)

There is a story for all of these people that have died. All too often, we never hear about them. Is the crane ok? Don't judge it by the dollars, picture Leah. I'm sure that if you are here, you think of cranes this critically already. Keep up the vigilance. Many of us have Leah's at home to get back to.

Dec 5th, 2002

Lourdes France - Back in 2002 a Tower Crane collapsed injuring two and destroying three buildings. A third was pulled from the rubble. A child had been buried and was transported to the hospital with no significant injuries. Dogs were used to be sure that the area was clear of any other victims.

I am continuing my search in multiple languages to have full records of the history of Tower Crane Accidents. I know of another in Malaysia that I haven't gotten put up and I have many more languages to search in. But if you know of accidents that I'm missing, don't hesitate to email them to me.

Thursday, July 8, 2010

November 22nd, 2009

Fuyang China A Tower Crane collapsed killing four people and injuring 2. The job site has at least three cranes with the one in the accident being a different model than the other two. No good details were found showing why or how the accident happened. With most Chinese accidents I'm just happy to gleam what I can.
What I find interesting in this one is that the counterweights don't have reinforcement inside of them and the one is pulverized. I'm just happy that I don't recognize the brand or model of crane. As I used to say as when I was an iron worker and saw a problem, "That's not my chicken to worry about."


May 21st, 2009

Pujiang Town, China A site with three tower crane collapsed back in 2009 that I had missed. The interpretation of the reporter is that the first crane collapsed "at the bottom" and fell into a second crane forming and "X". One person was killed and 8 were injured.

The accident occurred late in the day which may explain the limited death rate for two cranes collapsing on a working job site. Those injured were on the building and working inside on the floors structurally completed.

I was unable to find more pictures or stories to help put a bigger picture together.


Monday, July 5, 2010

March 26th, 2010

Krasnoyarsk Russia - A QTZ-125B Chinese tower crane collapsed during the construction of a residence building. The crane collapsed falling into traffic on a busy road (video). The report notes six people "affected" which may be part of the dry factual nature of some of the Russian culture. On the informative side, the government is releasing details about the cause of the accident.

The following is a quote from the story and is noted as a quote from the investigation. "The gap of defective high-bolts holding the crane foundation was due to the presence of nonmetallic inclusions in the metal high-strength bolts and inconsistencies in the mechanical properties of the requirements in the production of works in accordance with passport data, which led to the fall of a crane" The inclusions reminds me of a story from Cranes Today where Felix Weinstein warned about poor quality steel in tower cranes. I have in fact found poor quality steel in a mast section myself, delamination. The Chinese are not known for taking the extra steps to ensure safety and quality and I would never recommend a Chinese crane at any price. Even if you have some that are reputable, how do you vet one over the other?

I wish that we could get more of these stories on the actual cause of accidents. Bolts for towers could be replaced, behaviors could change, and 6 people wouldn't be "affected".

June 8th, 2010

Voronezh Russia A Self-Erecting Tower Crane was blown over in a storm. No one was injured by the accident. Apparently the storm was strong enough that no one even heard the accident over the rain.

Winds, particularly gusting and winds that change direction quickly, are a dangerous for cranes. We've seen video of cranes not changing direction quickly enough even when they are properly weather vaned. If you know that your self erector is about to be exposed to winds over 90, fold it down. If your crane is to be erected in an area known for winds, consulting your ASCE 7 standards for wind loads on structures and the wind maps would be advisable.

June 22nd, 2010

Kamchatka, Russia Way out in the Russian Federation Islands at the end of the Aleutian Islands a Island 800 miles long with a population of 400,000 suffered an accident involving a tower crane during a dismantle operation.

The accident appears to have involved a jib failure noted as a "refused hydraulics". But that really doesn't answer too many questions. Looking at the crane, it is on a cross base. Noting the missing pendants and jib connections, it looks like a luffing tower crane. To be more accurate, it looks like a portal crane generally meant for longer term installation. The "refused hydraulics" could have caused the jib to fail if the crane was being climbed down.

When a climber is set up, there are supposed to be check valves in place and pressure checked prior to use. Often you push the climber into the pin pockets, pin it off then push up and see if you have bleed off on the pressure gauge. If the check valve works, even in the event of a hose or coupling failure, the Hydraulic ram should not catastrophically fail and cause the crane to fail. Sadly in a location as remote as Kamchatka, the failure of the check valve would not cause anyone to say stop everything for four days until we can get a new one. I of course am presuming quite a bit and only bring this potential up as speculation and education of what can go wrong.

July 2nd, 2010

Hanoi South Vietnam

A tower crane building a 20 story building collapsed. Three workers were killed, but their locations, be they on the crane or building weren't indicated. One of those that died was the crane operator.

The crane appears to be an old Kroll design judging by the tower top and turntable. if that's the case, the crane could be as old as 50 years and it broke just below the turntable. I'm not personally familiar with handling the model of crane. The quality of the picture is poor and so i'm not sure if the area that broke is a part of the turntable still or in the mast. If anyone can tell, feel free to comment.

I've said it before, and I'll say it again, I don't know why these old cranes are up and running. Micro-cracking, corrosion both internal and external, accumulation of dents or other items not addressed because there isn't the value left in the crane to address the problems are realities to consider. If you are a General Contractor, you should consider that even if you have the best inspector in the world, you have years of paint covering corrosion and many layers of paint. Filling in dents with bondo is cheaper than replacing a lacing. and other things prevent a good inspector from finding every potential problem. Not to mention, how much money do you save going with the older crane when it increases your downtime and your exposure to accidents?

Cần cẩu tháp sụp đổ

July 4th, 2010

Leshan China

5 workers were atop a 30 meter tall crane when it collapsed killing 2 and injuring one. The two that survived without injury climbed down the mast.

Looking at the picture it would appear that only the superstructure collapsed. With two being on the tower, and an operator in the seat, two scenarios come to mind. The first and most likely is that the crane was going to be climbed and was not properly attached to the climber. We've seen this happen all over the world and sadly is a common mistake.

The second scenario that comes to mind is possibly the crane was being prepared for dismantle. If the mast bolts are loosened too, much or prematurely at all (depending on model), the crane will be subject to collapse.

This job site and the crane both appear to be in terrible condition visually, which often speaks volumes to me.