TRANSCRIPTIon

Klaus: Special construction side-roads. Partially erected, so partially parted, maybe on some chipping extension on the crane and suddenly, the crane tips over. So people try sometimes by traveling on partially erected crane that tipped over all of a sudden on times. We are talking here on some typical incidents, it’s very important for us to understand that what we see here is what I would call outside influences. It’s something outside of the system crane, acting on the system crane, and is the system crane the crane itself cannot bring the loading to the ground because the ground gives way. So we are here talking more about pure physics, and what we are talking about is more or less same for all sites and all types of equipment. As you can see the pictures here, I’ve of course taken care that we do not have custom manning on cranes, but it happens to our whole industry in all places all over the world and it happened with all types of equipment, irrespective of the equipment in manufacturers because again, it is pure physics. It is outside influences. People come to this trying to check testimonials you can see here on the picture later on again. We have to talk a little bit on loading distributions and understanding what happens if loads go into the ground and we have to see what happens if ground gives way, which shear failure and what happens when cranes travel along side. We have prepared some videos. Unfortunately, we have issues with the bandwidth of transferring the data, so it might be a little choppy and we have some issues with the audio, so we have the great pleasure to synchronize with myself while playing this video. Let’s give it a try. What I actually wanted to do is show us some very simple stuff, some information about load distribution. Now we have an issue here. Okay. So choppy on my side as well. So I went to my seller and simply put some wooden bark fuel on the table and if it’s not working like this, I just move on a little bit. The law of Murphy, if it can go wrong it will go wrong. So we tried it, and obviously, it’s not working. Now, I should be introducing some very simple pieces of equipment which I bought from my seller some wooden bark, there’s a small box I’m now holding in my hands, with a little bit of gravel, we will use the gravel a little bit later. I have now prepared my ground model so I have this wooden barge which is lying in front of me that I’m holding up now. With this wooden bark, I will try to simulate a ground. I think anybody who has walked on a sandy beach maybe would believe that wet sand will release some imprints when you walk on the ground, and when you see the imprints, sometimes they go past back a little bit. So, there is definitely some elasticity in the ground. We have to simulate the viscosity of the ground, and if the video would move on, we can see that we can do it by just working on some very simple springs on the bottom of the wooden barge. Unfortunately, it’s not working this video. So I’ll try to move it on a bit, very sorry for that. Trying it out, it was working before. Okay, I think it definitely makes sense to continue with the video. Very sorry for that.

Jonah: Yeah, this is Jonah. If you just want to explain what you did with your experiment, we can have the slide back on the screen. It doesn’t look like it’s going to play through. So just the idea behind it that would be okay.

Klaus: Yeah, I think we will see it in one of the PowerPoint slides a little bit, later.

Jonah: Perfect.

Klaus: So the idea behind it, what you can test yourselves and your seller, just take a wooden barge, some wood barge and then get yourselves some springs, put the springs into the hole in the wooden barge, so the barge would start to keep the springs from just running away, and then I have just cut out the woods, the crawler, on the sides of the crawler, and if you imagine that you put this on the side of the crawler with the springs, and you push out in the middle, you will see that the crawler is sinking in. so the springs, the way they are, press a little bit. If you press the crawler on the wooden crawler mark in the middle, all the springs would be loaded equally. So you have a rectangular loading distribution. Then imagine you have the wooden crawler piece and you move it a little bit more to one side, you put a little more to the front, then you would see that wooden crawler barge thing would be more in the front area, now coming up the picture, would be a little bit of a delay. So this would still, my hand is pushing in the middle. So, we will see if the video will go on and all the springs are loaded equally, when pressing, the crawler model would sink in. later on, if you move your force a little more to the front, you would see that you would uneven load distribution because the forces are then going more to the front. I think that I would close this video now. Now that it makes more sense to continue with this one. So let’s go on.

The PowerPoint is on. So Jonah, is there anything you can recommend to me, now that the PowerPoint is not working?

Jonah: I can take back control of the screen. If you can just present from what I’m showing, we can do that. Okay? Give me one second here. We apologize, everyone, for this. Everything seems to work out in the test run. But it’s okay.

Klaus: I think this is the one we need now, Jonah. So if you can stay with me and keep this picture here. So this is what I wanted to present. On the left side, you see the symbolize of the crawler and you just have flipped the side of the crawler so everybody can see what the crawler looks like. You will see we have a symmetrical loading of the gravity of this crane; it is pushing in the middle of the other carriage. We get an even loading distribution on this crawler. Here we are. If we then move the weight to the front, which could be the situation if you have a load already hanging on the entry already, yes. So the center of gravity, the start will now move by the arrow, more to the front. Then we get a triangular loading distribution, but you’re still on the middle line. That means your triangular loading distribution on the left side and right side is still the same. So now you mention we now move, we turn the crane, we turn the left, so in this very moment the center of gravity is to the front and to the left and we now observe that the loading on this left crawler, to the center left of the crawler is getting the highest areas of the crawler, which are not loaded anymore. The right hand of the crawler is loaded, but not that high.  I think this is very important to understand this one because the misconception that people think of, hey, there’s this big crawler underneath and loading will be distributed evenly, but it’s not. Let’s say all the velocity of the crawler, it’s not only the area covered by the crawler, it is about the reaction of the ground. So, jump on one more slide. So what we have here is a little bit of data and a lot of engineering more data. We have four different types of soil, hard rock, soft rock, very compact sand gravel, maybe compacted sandy gravel, or loose fine sand, and we see maximum allowable bearing value in tons per foot. You see that the effect on is by 100 in between loose fine sand and hard rock, and on the right side, we have the same figures but in psi. Below, I tried capture some data on a typical 600t or 660 U.S. tons crane, which is kind of commodity of crawler crane. So these cranes have weight which are in the range of 440 tons, and the typical dimensions of U.S. cranes and crawler, then you come assuming that the crane is without loads, set up in a way that the center of gravity is set up exactly in the middle of the under carrier, you will come evenly to a theoretical loading of 1.6 tons per square foot and 1.6 tons is already something which usually cannot be taken by loose fine sand. Then if you have the right contact on the floor table, you will see the typical feet on the ground loading with loads; you can see that there is a big variance. The big variance will have course, because it depends on the way how the center of gravity is located, or where the center of gravity is located, as we have seen in the previous picture. So, we would even see that we have something in between 3.1 up to 10.4 tons, and maybe even above 10.4 tons per square foot, which means you have to have a definitely very compacted sandy gravel or maybe even more on the ground side or you use something in between crane and ground, which means cribbing, matt, and sand. Next slide please.

Mike: Okay Jonah, why don’t you go ahead and switch it over to my screen for presentation and I’ll track right along with Klaus on the information. Is that alright?

Jonah: Yes, switching it right now.

Mike: Okay. Klaus, can I bring up a question for you?

Klaus: Okay.

Mike: The key is that the value showed down here, in that the theoretical, we would still be exceeding. Is that still greater even for the loose soil, so that’s a trigger point right? That a problem right?

Klaus: Yes.

Mike: Then, over here, on the typical ground loading between 3.1 and 10, we have to be up in this range, and likely, in here right up to the soil to the soft rock type category for good support?

Klaus: Let me make it absolutely clear, which means if you rely just on the area of the crawler tracks, the crane brings to the side, and you will make improvement of the ground itself. You would do it on the ground, protecting the ground. Of course, on the other hand, you could operate and have the max of cribbing underneath the crawler.

Mike: Right. Okay. Let me, can I go back to this particular slide. This condition, this is much greater loading here and on left, and much less on the right. This can also occur, can it not, with a boom up and counterweight condition without load?

Klaus: Yes, of course. It depends on the face of the load distribution, whether it’s rectangular, spreader beam, or out load or triangular load, there is a difficulty in between left side and right side of the crawler simply depends on the position on the center of gravity. Gravity is combination of all loads acting on the under carriage of the crawler which is the superstructure, which is the boom, which is the counterweight if you have an additional super lift counterweight then this load will be activated and if course, it would the position of the boom. So if you have the boom in this position and the deadweight of the boom acting weight then it would be more point to the front and you would see it here, and of course, you should not forget the load. But, the principle is physics behind, as I said, loading distribution is just related to the center of gravity and then the amount of weight acting on the under carriage depends on whatever you have about the under carriage.

Mike: Right. Okay. I’m going to go to the next slide for you. Will this work for you?

Klaus: Yeah. Good. So let’s say, when I do those presentations, I often have the question, yeah but if ground gives way, we would have a very sophisticated system on the crane. Couldn’t the crane help? My answer? No, because it’s already too late. If the ground gives way, it’s too late. If you get an indication that for whatever reason the ground gives way and center of gravity, it’s too late. Then it will start moving, and this is exactly what you’re sketching here. Just imagining we have this truck crane sitting somewhere on the ground and in this colored area, hidden gravity or spot, in the ground. If this area gives way, any reading from center from gate would be too late. There is no means of having an automatic system reacting because what is in the very moment it gives way, what is the best way to behave? If it just loads on as fast as possible, could be one possible solution. But depends on what is on the load. Is it maybe if you’re turning the crane, you should crane just one come over continuation of the flowing and move it faster to come over this sweet spot or is it going backwards? It depends, of course, on the set up of the site. Whether they are people moving around other obstacles, or are it to increase some of the loading condition? Might increase the radius and bring it in as fast as possible to a bigger radius where this is higher loading on this outrigger? That’s then ground the load, putting it on the ground. There are so many influences on the rear adjustment side that no automatic symptom can up to the experience of an operator who knows what things on the job site are to be observed, or if the job site develops over time to make the right decision in the very moment that such an incident happens. Once again, you should take some precautions at the incident not happening.

Mike: The load can be, if the crane tips down slightly, the load will be going outbound, outboard from the crane and potentially compounding some of the loading to the area and increasing the radius?

Klaus: Yes, so this is adding to the problem of course. For whatever reason, the ground is sinking in; you would observe that the crane is lifting in the direction of the outrigger, which means you get an increase of the radius, which means you get even higher loading on the object. So this is a mechanism where the loading is getting higher and higher, more or less, automatically.

Mike: Okay. Very good.

Klaus: So we can give it a try to play this one video because this is a little bit particular. But, give it a short try. Maybe Jonah, you can try to start this one video once again. Which is the second video?

Jonah: Sure. Let me just...

Klaus: Maybe you can put those videos later on YouTube or something like that. I will check whether I can do it.

Jonah: Okay, I can pull it up on my screen here. Let me take that control. We’ll give it a shot. I will see if it’s complete. Okay. So looks like it’s going pretty well.

Klaus: Just putting aside these other stuff, picking a small plastic box with some gravel in it. So I tried to do some experiments with some, I had lentils, I had ice, I have everything in the kitchen. I had some tissues- good with gravel. I now have the gravel in the small plastic box. I’m using this piece of my crawler just to push on this gravel, and now we have a close-up. So I push in a little harder, and harder, and harder. We can see that, just before we get a kind of settlement, we wouldn’t pass this and all of a sudden, it gives way. So there is an increase of force related to the settling of the stuff. All of a sudden, all the whole ground gives way. Unfortunately, because of the video, we cannot see how it gives way. Maybe you try it at home. So sinking and sinking in. once again. So this is what you call settling. Then we small increase of the load and immediately it goes down, so we now go back to the other screen.

Jonah:  Sure. I’ll pass it back to Mike here.

Mike: Okay.

Klaus: Thanks for your support. So this is just a picture of what we just had the video. If you just move one more forward pleases. Sorry, it’s an animated picture. So you’re not in PowerPoint now, right?

Mike: Correct.

Klaus: Okay. We just move on. If you just keep this picture here you would see that this wooden barge is now pressing against the gravel. It has already sunk in a little bit due to what you’d call settling. Then there is a wedge underneath, which you just push forward on the side, it’s just pushed to the side and it’s just coming up. Exactly, as you are indicating. It’s just getting up; we have in this moment what we call shear failure. The shear failure of the ground is just you should come to the forces which can be transferred between the different gravels and different grains of the gravel. So they can take loading and compression loading and they can take some kind of friction loading in between this grain. It should come above this, friction loading; you would have sudden collapse of the ground which is called shear failure. This exact point is known as the angle of repose. So if you just go to the next picture, everybody has seen this angle of repose. You see it here. It’s just this angle where this material naturally in space, it’s this angle where it can take forces, and everything would be steeper and it would be higher force acting from the top, in the scone. It would lead to a collapse of the area. Exactly here, you see the angle of repose. Okay, next picture please.

This is the one picture we already have seen, which a situation of somebody traveling with a big crawler crane. 96 meters of main boom, 350 tons metric load on the hook, locked conduit on the crane, super lift conduit on the crane. So this was very high loaded. They were traveling from some area which was compacted and they were coming into the sweet spot on the top side. All of a sudden, the ground gave way. It is an example of shear failure. So it was obviously leading more to the one side, the front, the left crawler, which sank in, the front one. For one or the other reasons, the highest loaded area or the softest part of the ground and the whole thing fell over and a couple of people were killed over this incident. It was a little bit. I’m tired of seeing those pictures, but I try to explain the situation to you to hopefully, we will do a better job in the future together. Next picture please.

So, if you note down the capacity of ground, it’s just another instance on the lower left side. You see the situation just before the incident. Somebody has set up the crane on a road which was not totally leathered, was not totally flat. They tried to rescue the truck, which you see in the background, somehow the truck has left the road, and they were using some flake underneath the outriggers, thank you very much. Obviously, these plates were not flat at all, and the whole ground- because it was very soft it was very wet, the whole ground gave way the very moment when it gave way there was one part of the plate which was still supported by the rope, the other parts were effacing on the soft metals, and on the wet area, then the whole thing tipped over. The crane fell to its side. Unfortunately, killing a person. So good preparation before you do such a job is paramount even in situations where you are under a lot of time pressure, for example, if you are on a rescue operation, everybody wants to have it done as soon as possible, but I think they’re of no excuse for hurrying up. Especially when you see those results. Next picture please.

Travel on site with loads. I took this one picture here. It’s not showing up nice, transport. It is of a big wind turbine you see that this is a massive load. I’m not sure about the weight of the load, but I’m guessing it’s exceeding the 150 metric tons. Usually, the load is backed by lots of excess. You see executive gravities; the center of gravity is somehow at its heights. This is something we have to observe as well when we are traveling with loads. So next picture please.

Travel on site, exceeding of load capacity on site here we have a combination, in this one incident, is narrow track crawler crane. So it’s a crawler where you have for reasons not being normal crawler specs, crawler made especially to travel on fine sands of job site conditions. The crane is partially erected. So very high center of gravity. Now that we see, because in this area by the ground gave way, there were some bumps underneath the roads, so the roads were somehow prepared, but obviously not prepared in a way that it should have been. So it started to sink it.  So the high center of gravity came over the tipping line and job over the crane line somewhere over, and it cost you a fortune to recover such a crane. Next picture please.

Similar picture, but even worse. So this is a crane which crane retracts and extends its crawlers. Here, somebody has retracted the left side crawler, whereas the right side crawler is still fully extended. The spot, now we have the center of gravity but we have not moved the left side crawler closer to the center of gravity. What does it mean? Of course, if you use the loading on the left side crawler is lower than the right side crawler and this is the result on a job site, where this crane fell over. We see that they already have rescued the crane because they tied it to another vehicle on the right side, to prevent the crane from totally falling over. But, it will cost you days to lift such a crane. Next picture please.

When we travel with load that has partially erected cranes, it’s all about spending time. If you’re traveling on job sites where you have to erect wind mills, you might have a number of items to be rejected with the same crane and if you have half of the crane and suddenly another half falls, it costs time and money. Though people try to move the crane partially erected, which can be done if you take care that crane is load prepared, that load is taking the loading coming from the crane and if you take care of the in case the load gives way, you have some additional measures, like training wheels on a kid’s bike, you should extend the outrigger so that in the very moment when the crane would sink in, the outriggers would make contact with the ground. To be honest, I’m not one to be happy with the picture, because you see on the left side crawler, but on the right side outrigger, there’s still a distance in between the underside of the crawler of the outrigger patch and loads. So the crane definitely will lift to the side until the contact is made between the outrigger pad and ground. I’m not sure the ground in the area where the outrigger pads moving over has been prepared, in the right way, so the ground in this very moment when the crane would then lean onto the outriggers, that the ground would be able to take the load in. so, it’s not only that you have to have the outrigger extended, it’s going by the manufacturer’s menu, as well that the ground underneath the outriggers which is in the training wheel of the kid bike, that the ground is prepared to take the load in just in case something happens. So next pictures please.

This is just getting some other examples so that you see. In the middle picture, there’s crawler tipped over, which is just traveling somewhere in Norway, this is very close to hard drop on the grounds and this is special equipment radio for some parts of the travel, you can read this additional outrigger plates and they have just demonstrated that they can lift up quite high. So this is what we call a narrow track. As you can see, again, in the lower left side you see a struck crane which is troubling. They still have on this crane, what we call super lift crane on the counterweight. Obviously, the counterweight has been taken off, the main boom has been taken off, so they have to wait and by bringing the crane into this position, having the super lift pointing to this picture, they make sure they have an equal loading distribution on the tiles of the lead. Next picture please.

So this is just a competition crane. It’s not a Terex one. If you just want, this one is traveling as well. Guess where the center of gravity is, if you see those pictures, the center of gravity is definitely not closer to the ground. It’s somewhere higher in the air, up in the air. If you imagine that the center of gravity is up in the air, and you have the width of this trailer, which is 2.55 meters, then you see that the spread, the sideway spread of the trailer, could take loading is smaller than to the heart of the center of gravity. I would even guess that it’s even higher. But I don’t think it’s that exact. Thank you. Next picture please.

These are the consequence. So this is a crane which was struggling on a jobsite road specially built for this purpose. Obviously, the road is not flat and leveled as you can see on the top picture. Obviously, the object has been put out at least partially, but as far as I can guess from these pictures, I have not been on this accident site, but I guess that in the very moment, the crane might lean to the right side then the ground may not have taken the load off of the outrigger. So then pulling out of the outrigger can take additional loading, so the crane leans to one side when the crane leans, is of no use if the ground is not prepared. This is a sketch here, you can see.

Mike: And that’s it, the center of gravity, just approaching that left hand area.

Klaus: This is exactly the problem. If you come with a center of gravity over these lines, then nothing can stop you. It’s even; we’ll see in the next picture again, it might even be worse if you move on one more picture please. So here we see again, the center of gravity so it’s one of these animals. If you set up, usually on public roads, the crane would transfer the object so the whole superstructure would be taken off. When traveling off-site, the superstructure is on the cradle for the counterweight which could be the A-frame on the part of the super lift; you see that the outrigger has been extended here. But, they are, the parts are, some distance from the log. So if you extend the outriggers, if the object pad sliding just above the ground, making the distance between the underside of the and the ground as low as possible, if somebody observing affect somebody else, struggling. Again, the ground is capable of taking loads. Next picture please.

This is now coming back to your sketch two slides before. In principle, the question is where is the tipping line? As long as the suspension is not overloaded, and we have the emergency suspensions here, a new base. But you do not forget that the wheels themselves are reflecting. In the very moment, then the loading would get very high so that the hydraulic suspension system are loaded up to their limit, they might begin the situation that moss, the protective moss, and the cylinders open to prevent the cylinders from bursting. In this very moment, the tippling line would switch from the wheel base to the suspension base. So this would even be a smaller base. Next picture please.

It’s just a picture that I’ve taken from a court case I had several years ago. It’s a crane like shown in the menu. It provides information on how you troubleshoot such a crane so you reflex the main boom and still has 36 meters of larger side of the crane; you still have some 24 metric weight counterweight on the crane. You set up the main boom in a certain angle, you set up the mounting chip in such an angle, you keep an even loading distribution on the wheels of the vehicle and you get the center of gravity, which is just the red dots on the two right side pictures. The center of gravity is somewhat 8 meters at height, and if you compare the 8 meters base of few meters, you see that it does not much tipping until the center of gravity is over the wheels of the 8 meter base. If it’s overused and you have extended your outriggers, you have your outrigger pads just sliding above the grounds and the ground is not capable of taking the load, then the crane will just be kept by the outriggers. But the crane is not a kid’s bike over as a comparison. Then you would prevent the crane from tipping over. If the ground is not capable of taking the outrigger loads, it will stay there. If the distance in between the outrigger pads and the ground will be too high, you might have a situation where the crane stops and is moving moving, and then it’s just setting on the outrigger pads but it has just energy because it is just moving and it will fall over as well. So there are several conditions. Outriggers pads sliding just above the ground and prepare the ground of the outrigger pads will be traveling over. Next picture please.

This is what the consequence is. Exactly the crane that was shown on the sketch before. So the crane, which traveled on site, but the condition of the outrigger was not extended. It was traveling over this spot several times. So the ground was getting softer and softer because the crane was always traveling over the place. Then all of a sudden, the crane fell over, it fell on the conveyor belt. The conveyor belt was fine, nothing piqued about the damages .so fortunately, nobody was injured, and nobody was killed. It was only money, but it was a lot of money. I can tell you and it could have been prevented if they would have fully extracted the outriggers. They would have the outriggers pads sliding just about the ground. So this would be the consequences. Maybe if we have, later on, the materials for the other people, we will include a link to another video because it will not stay that smooth. We just had a couple of days ago, an accident with a fully erected crane traveling on site and then falling over. It was very good practice to see what happened. On the other side, it’s impressive as well. We are sending out these messages that people should be careful. We are sending out these messages for a long time. Obviously, only a few people are listening. So we can see those accidents. The most recent accident again, was only money, nobody was injured. Yes, the crane driver was kept in for some time, the firefighters had to come and get him, but he was not really injured. But they would be today. People would be injured or killed.  Okay, next picture please.

Good. Next one please. Coming to the end. So first, and most important for me is, PLAN, DO, CHECK, ACT. Develop a plan. Do not start working with cranes without having a plan. This is the PDCA cycle, Plan, Do, Check, Act cycle. Plan, you have to develop a plan. Then you act according to your plan, or part of it. And then please take action. Something changed. Some of these assumptions when you were doing this plan are changing for whatever reason. And it is the conditions are no longer, no more as the plan. Take action if needed. Go to plan B. or at least stop over and I would tell you, usually, you’re better off if you have a plan B so you can switch off and continue. I have seen, unfortunately, where people only had a plan A, and the plan A fails, and they just continue, more or less, what they had in their minds. But conditions had drastically changed and the consequences can be fatal. Next please.

So, if we just talk about prevention preparation of the hard stand, so the place where the crane is located. You should establish the load acting on the ground. So come out the manufacturer’s documentation, you will achieve in the manual or company manual as well. Calculation tools as available where you simulate the loading condition, you simulation the load on the whole crane, you simulate the punching grid of the crane, and so on and so on. So you would see, okay, which are the loads which come from the crane which are acting wrong. Then, the next step is to investigate the grounds. What is the load handling capacity of the ground? Comes from civil engineering, talk to those people, it might be needed that they do some testing of the ground. They have operators, they can do it. Of course, more than once we have had situations where some people tend to use, which might be very helpful from knowing some men, some friends in the area of the lift to see if they, some old installations underground. This could create a lot of trouble. Then prepare the ground and level it. It might be the situation in addition to the ground preparation you’ve done, you are still above the ground – the loading from the crane above the ground can take. It is up to you to use the appropriate cribbing on it. Of course, we need to be careful there. The cribbing may fail. The load is not spread over the full area of the back, so if you have mats which are very soft, they will simply bend. Then, you would calculate: you have so many square feet of the mat, and you will distribute the loading over the square feet but this load is not spread over the full area of the mat, so the calculation is simply wrong. Cribbing may fail if the ground crushes it or extensively settling it. If the ground gives way under the mat, under the cribbing, we would have problems. Or if you have extensive cycling, which means you have expensive sinking in, of the mats, then you will have a situation as we discussed with slides like the pictures before. Due to the sinking in, the crane lifts in the direction of this one outrigger, the outrigger of the load is over this one outrigger, and when the crane leans over to this side, it automatically gets an increase of the radius which would increase the loading on this outrigger. Which means you get an increase of the loading on this one outrigger as well? So therefore, the ground itself must still be capable of taking the loads off of taking the cribbing and the mat, cribbing of the matt and the matt banks, which might just expect. Sometimes we have what we call horizontal flipping, cribbing out of wooden pieces. You have maybe very small outrigger plates of the crane, this outrigger plate could penetrate, could go into two or so of these wooden pieces and put them horizontally at height and then, in principle, your whole cribbing fails. So, what is often very helpful is get cribbing from wood, from timber and then have in addition, some steel plates on top to make sure that the load going into the timber is evenly distributed already, and then the load of the timber has a bigger area coming to the ground. You see the crushing of the plate on this way, and so it’s very important to not only have cribbing and mat underneath, it should be appropriate, but it should think it over to really understand what can happen there. Next picture please.

Ground conditions and preparations for mobile cranes or so in loads. We already discussed so that you take care that the outriggers are, especially with partially erected cranes, outriggers are extended as per manufacturer’s manual, that the outrigger pads are sliding just above the ground and that the ground underneath the pad is capable of taking the load. It is some sketch and you will find those sketches on many engineer, for civil engineers, we still have again, the angle of repose. So this angle, alpha, is more than the angle of repose. Of course, it depends a little bit, whether you have soft soil or you have more firm soil, and of course, what is recommended is that you do not travel exactly at the edge of your angle of repose so you have the characteristics indicated and you have additional pace mounted. Unfortunately, there are situations where you have to invest more money into these roads because they are getting bigger, but I think the trade in is that you will see a smaller amount of cranes tipping over. Money spent on building roads is, I think, money well spent. Next picture please.

This one I found somewhere. It says: the crane is just a machine, it has no brain. Actively watch what you have invest, what you think before, and please remember our PDCA cycle, plan, do, check, act. Wherever possible, have a plan B at hand. So I think that we have come to the end of the presentation. Next slide please. I would like to thank you or your attention, I hope it helps you a little bit to prepare in the future. I apologize for the difficulties we had towards the videos and the PowerPoint. Obviously, we have an issue with that, but I think that with the help of Mike and Jonah, we could figure it out and found a solution. So, thank you very much and it’s now time for your questions.

Jonah: Thank you so much, Klaus. Thank you to everyone on the line for bearing with us there while we figure out our technical issues. We did figure it out. The method we came to worked out pretty well with Mike being there. So we do have a couple of questions. I’ll start with this one, Lyle would like to know, how the loss of capacity is affected on non-operational ground?

Klaus: So usually you will find, on the manufacturer’s instruction, some information on the inclination of the crane. I think the information you have there is relying that you do not have other adverse influences. So let’s say you might be able, with some lifting to one side, to reach full capacities, but if then, for whatever reason, you get some winds blowing, some side effect adding to the situation if you come into some trouble. So in principle, mobile cranes on outriggers are intended to be fed up by means of the outrigger on a leveled way. So as far as possible, you should take care of crawler cranes setting on that leveled ground as well. So you have some additional cribbing or whatever. Please check that the cribbing and the mats are leveled as well.

Mike: Klaus, I know that boom deflection can add radius as well, which can compound the problem of being unleveled. So that might be a factor they would need to do, just taking into consideration. I think the first, Terex and a number of competitors established a load chart built on ideal conditions. Sometimes within 1 percent grade or 2 percent grade for testing conditions. But really, to establish that, it is the operator and the owner’s responsibility to insure levelness, right? That’s the first directive or order. To achieve the load chart’s rated capacities.

Klaus: Yes. For sure you have to take some assumptions, and you’re absolutely right. In principle we calculate load charts for cranes acting on grounds, we’re not talking of cranes on barges, this is different topic, if you are working on grounds, and we are assuming – more or less –leveled grounds where there is small gradients only. It’s really the responsibility of the job site to prepare the ground accordingly.

Mike: Okay. Jonah, we have any other additional questions?

Jonah: Yes. A little bit came along, the last is one Kim inquiring, are your outrigger loads determined from calculation, test data, or both?

Klaus: Sorry, there was a little bit of echoing in the background. So how we calculate outrigger mining, right?

Jonah: Yep. Is it determined from calculations or test data, or both?

Klaus: It’s both. So in principle, you calculate your outrigger loading because you do it during the conceptual and when they give you a product, you have to understand it upfront. But, then you go into testing and during this testing, you monitor the loads so that you at least ensure that you make no mistakes with your assumptions during the calculations. Yes.

Jonah: Okay. That one was pretty straightforward. I think we have time for one more. Jeff was wondering; how you can do small scale, localized, ground pressure testing. Are there any tools or instruments available?

Klaus: I’m not speaking as a mechanical engineer on the topic of civil engineering. But I know both because I have ordered both tests to be done on our tests when we were picking equipment. Pick out some area, some square meter, square feet, of a whole and do some testing so they have kind of a probe running through the ground and measure how the probe is jumping backwards. So what is the amount of energy absorbed by the ground, how it comes backwards, and the different methods to establish the loading capacity of the ground and there are consultants you can hire to do this job.

Jonah: Okay, thank you, Klaus. It doesn’t seem like we have any more questions. We just hit the hour mark here, so we want to respect your time. If you do have any questions, feel free to e-mail me, at Jonah@iti.com and I can pass some questions along to people who can give you the correct answer. I don’t have anything else now. Mike or Klaus, if any of you guys have some last words, and then the floor is yours.

Mike: We would look to see if we can forward, if possible, any of the videos that might be pertinent, or at least forward the link. If possible. If they’re not proprietary, from Klaus to the attendees that can be sent out by e-mail alerts. We just have to check the legalities of those being able to be released. We really appreciate Klaus, your being here and your presentation today. Very informative, and very helpful. I don’t think most people, in a confined work area, the amount of travel required for crane and the lack of preparation is the deadly mix. It’s sort of that perfect storm of events that without good planning, we have to retract. It’s almost as important as building a large crane pad, as also paying attention to the crane access route from point A to point B. it’s a huge element that I picked up today. Planning that properly and executing the preparation part, double checking, going to plan B if necessary. Finally, acting on those plans and calculations that you have provided. Outstanding information, Klaus. I’ll give you the last word and thank you for the contributions today.

Klaus: Mike, Jonah, thank you very much for your support. All of you, wherever you are, thank you for your attention, thank you very much for your patience in dealing with some more technical issues.  I hope the message came across. Take it to your heart, and thank you.

Mike: Okay. We’ll sign off today and we’ll be looking forward to having you visit with us on another showcase webinar. Thank you, Jonah – we can sign off. I hope everyone has a great weekend coming up.

Jonah: Thanks, everyone.