Inside Liebherr: Creating the Largest Mobile Cranes in the World | FD Engineering

[Music] the LTM 1750 a mobile telescopic crane without equal the construction site Colossus can lift incredibly heavy loads and transport them to dizzying Heights even over buildings despite its enormous weight this mobile telescopic crane made in Germany can get to its work site by Road and it's extrem extremely maneuverable for its length and width the construction of this Behemoth is a masterpiece of German engineering engines developed in-house huge telescopic booms and a whole load of [Music] high-tech aing in B verber Germany the cityscape is done dominated by the leapair factory the family company is the global market leader in the mobile and crawler crane sector around 30,000 of the German manufacturers mobile cranes are currently in service around the world on a site covering nearly a million square m a quarter of which is filled with production Halls roughly 4,000 workers build six mobile or crawler cranes each day King of the ltis Boom crawler cranes is the LR 13,000 the largest mobile crane in the world with a maximum load capacity of 3,000 tons it can even maneuver on site with a load on the [Music] hook another much more frequently requested record holder is the LTM 1750 mobile telescopic crane [Music] it's the largest mobile crane in the world that can drive on the road with its enormous telescopic boom mounted the 108 ton gross weight of the LTM 1750 is spread over nine axles which equates to 12 tons per axle the maximum permissible axle [Music] load the wheel steel Colossus is 22 M long long 3 M 90 high and 3 m wide four of the Crane's axles are driven and all nine are [Music] steerable the LTM 1750 can lift up to a maximum of 800 tons with its 52m telescopic boom with the lattice jib attached its maximum lift height is increased to 15 52 M the load the crane can lift depends on the operating radius even at the maximum 160 m it can still lift 1. 8 tons the basic version of the LTM 1750 costs approximately €4 million it essentially consists of four elements the carrier including Outriggers the super structure consisting of the rotating platform and power pack the engine used for operating the crane and the telescopic [Music] [Music] Boom the metal fabrication shop at the Ain Factory this is where the frame sections for the mobile telescopic crane are made they consist of over 1,000 individual parts that all have to be joined together exactly according to the fabrication plan a job that requires Precision work from the welders once a part is in the right position it's provisionally fixed with tack welds only afterwards is the actual seam welding performed at this Machining station the finished mid and rear section of the carrier chassis are upside down threads are cut into the mil bearing surface for the rotating superstructure of the [Music] crane the 7. 1 ton frame of the rotating platform fresh from the fabrication shop in order to install the first component the assembly workers have to turn the massive structure upside down the rotating platform is part of the crane superstructure which supports the telescopic Boom at the front and the power pack and counter weights at the back the sing ring forms the connection between the rotating platform and carrier it allows the crane superstructure to rotate 360° when in operation the assembly workers now have to attach the sing ring to the rotating platform form in order to get it aligned just right they screw centering pins into holes in the rotating [Music] platform located on the centering pins the sing ring which is also referred to as a sing bearing is attached to the super structure using 300 BTS [Music] the roller bearing sing ring we see here consists of an inner ring and an outer ring the inner ring is bolted to the superstructure which is on its back here and the outer ring will later be bolted to the carrier there are roller bearings between the inner and outer rings that allow the outer ring to rotate around the inner ring [Music] the mechanics run the hoses for the hydraulic system along the frame of the already primed carrier and install electrically controlled hydraulic valve modules the carrier is basically the chassis of the LTM 1750 with driver's cab engine Outriggers axles and wheels the mobile telescopic crane is equipped with hydraulic axle suspension mechanic maximilan Schulz has to install some crucial components for it the so-called hydraulic accumulators sper sits here in the mid the axle will later sit in the middle here the axle is supported by two hydraulic shock absorbers one on each side they're filled with hydraulic oil and they need hydraulic accumulators to work the rear section is filled with nitrogen at a pressure of 35 bar which is kept separate from the oil by a membrane if the crane drives over a pothole for instance oil is displaced from the hydraulic shock absorber which will later be connected to the rest of the hydraulic system here and is forced into the hydraulic accumulator the membrane gets forced backward compressing the nitrogen and thus absorbing the impact from the shocks the mechanics have to connect 18 such hydraulic accumulators to the hydraulic suspension system two per [Music] axle the power pack is part of the super structure it's basically the engine for operating the crane it's 435 horsepower 6-cylinder diesel engine Powers hydraulic motors and pumps to operate the cable winches and generates oil pressure for raising lowering and extending the telescopic boom and turning the rotating super [Music] structure the power pack weighs a hefty 16.

1 tons which is why it can only be installed once the crane has reached the job site it sits between the counterweights and lifts up the entire ballast tray that is the Crane's counterweight the raising operation is performed by these ballast cylinders they're 2. 3 M long and weigh 2. 6 tons each assembly workers Thomas clay and alexanda ha now Mount them onto the power pack [Music] they have to take great care when sliding them into the mounting points to avoid causing any [Music] damage this 70 kilo pin locks the ballast cylinder in place during transport and after picking up the ballast tray finally the mechanics tighten the ballast cylinder retaining bolts with a torque of 1,6 00 Newt M the hydraulic unit supplies the required pressure of 284 [Music] [Music] bar in the large crane facility the mechanics are finishing installing the mobile telescopic Crane's running gear Manuel Zen and Luca schat lift the final axle into place it's a non-driven axle that only weighs 1 ton the four driven axles weigh 1.

5 tons [Music] each the axle is now at the right height the men fasten the axle struts to the axle mounting points on the carrier these adjustable axle struts ensure that the distance between the axles remains exactly the same this is important for tracking steering and Power [Music] transmission the next job attaching the hydraulic suspension cylinders to the axle the mechanics slowly lower the axle tap in the axle pins and secure [Music] them next up is the steering system installation of the steering rod there mecal connection to the first axle and the steering is hydraulically assisted a purely mechanical system would be impossible you can see the cylinder up here that's the hydraulic assistance like the power steering on a car the steering linkages are connected via Bell cranks to axle 5 the rear axles are controlled by another steering system the remaining four axles are steered electr hydraulically via hydraulic manifolds axle six and seven via these manifolds here and axles 89 by the manifolds at the back the two independent systems allow the LTM 1750 to steer the rear wheels in a different direction to the front wheels this makes the mobile telescopic crane extremely maneuverable [Music] a big advantage in city traffic like here in Cologne and for entering difficult to access construction sites when at the job site it's able to maneuver well even where space is limited the manufacturer also adopts a dual approach when it comes to the braking systems all of the axles are equipped with disc brakes and there's an Eddie current brake fitted to axle 6 as well the Ed current brake generates a magnetic field that acts on the drivetrain while causing minimal wear this is the preferred system as it increases the life of the disc brakes once the drive shafts are fitted the workers must turn the carrier the right way up again to do this the mechanics have attached a motor suspended from a crane hook to the rear of the carrier the second device required for turning the carrier over is this giant wheel the mechanics place the 3. 9 T rotating device directly in front of the [Music] carrier Manuel Zen and Luca schat now raised the carrier which now weighs 23. 3 tons they then maneuver it into the rotating device and secure [Music] it now Luca schut just has to detach the chains from the front of the carrier then the rotating process can begin [Music] the rotating platform which will later sit on top of the carrier is almost finished electricians and mechanics run the last of the connections for the cab from where the crane will be controlled when on site the mechanics are almost finished running the connections to the carrier the lines pass through the sing ring which will be bolted to the carrier during final assembly the rotating platform has a cable winch but no engine of its own a special feature of this crane is that the superstructure engine is not installed on the rotating platform but in the power pack because the power pack is transported separately to the jobs Side by truck the crane has to rig itself like here at a construction site near flansburg the LTM 1750 with its maximum permitted gross weight of 108 tons has already maneuvered into the correct position and extended its front Outriggers first the 2-ton load block through which the Hoist cable runs must be mounted then the mobile telescopic crane attaches the rear Outriggers which weigh 4.

5 tons each once extended the crane no longer rests on its Wheels but is supported solely by the four Outriggers now the crane operator can place the 11-ton ballast tray on the carrier of the mobile crane addition counterweights are then loaded onto this tray the LTM 1750 can accept a maximum of 204 tons of ballast now the rotating platform engine the power pack arrives by truck it weighs a massive 23 tons the crane operator sets it down behind the rotating platform between the counterweights only when the power pack also known as the primary aggregate has been installed can the LTM 17 50 operate at full power the fact that the crane was able to rig itself even without the power pack installed is thanks to an important component of the rotating platform this is this second this is the secondary aggregate the so-called hydraulic shaft there's a pump fitted to the carrier engine it transmits pressure up to the rotating platform feeding the hydraulic motor that serves the entire pump circuit this allows the crane to perform all movements without the power pack just at a reduced speed and naturally with reduced power the blanks for the telescopic boom are supplied by subcontractors the workers in this shop turn the pre-prime tubes into finished booms they consist of an outer section known as the boom base and three telescoping sections Andreas scus and Mario K are currently working on a boom for the LTM 1750 specifically on the boom tip the industrial mechanics fit the head and neck shivs made from a special plastic the Hoist cable will later run over these shivs the more shivs the less power the crane needs to raise a load it's the same principle used by the overhead cranes at the factory [Music] at the base of the telescoping section the industrial mechanics now have to install a locking mechanism first so that it shrinks a bushing has to be cooled down to minus 196° C in liquid argon a noble gas Andreas scous places it into a boar when the bushing warms up to ambient temperature it expands and sits securely in [Music] place a steel spring is then placed into the boore followed by the 70 kilo locking pin which has a mushroom head on the bottom end finally the locking mechanism is bolted to the telescoping section a mobile crane that weighs an excess of 100 tons needs a massive engine to power it the LTM 1750 is equipped with a V8 Diesel built inhouse by the crane manufacturer the 16 L engine produces 680 horsepower Le attached to the leapair engine is an automatic transmission from ZF and above it are the hydraulic pumps for the steering Outriggers suspension and ventilation systems lifting the 2. 5 T unit into place is a tricky job mechanic maximilan Schulz gives instructions from above while his colleague Daniel kroa operates the overhead crane little bit higher then we'll turn it okay that's enough probably have to move it a bit further forward the mechanics have to precisely line the engine up with mounting points while making sure that no hoses or cables get trapped 10 minutes later the engine is in the right position and the mechanics can lower it maximilan schz and Daniel CLA now position the engine so that it sits exactly in the center of the chassis to do this they suspend a plum line from the center of the engine and measure the distance on the left and right to the [Music] frame 1 cm difference that's [Music] good if the engine wasn't located just right the mobile crane center of gravity wouldn't be exactly in the middle and it wouldn't be possible possible to connect the universal joint of the drive shaft either the drive shaft Powers four of the nine axles via transfer cases but attaching it to the gearbox turns out to be difficult I'll go down and turn the drive shaft okay the holes in the drive shaft don't match up I need to turn the other drive shaft so this one up here lines up going a bit further in this direction yeah further okay stop there it's good the drive shaft can finally be bolted to the gearbox the next task for maximan Schulz and Daniel CLA is installing the radiator It's a combination radiator for the engine coolant the hydraulic oil the air conditioning system and the charging air cold air contains more oxygen which improves combustion of the air diesel mixture in the engine the mechanics first attach the air hoses for the air conditioning system and charging air followed by those for the hydraulic oil and the engine coolant finally they bolt the radiator to the carrier chassis [Music] on the other side of the assembly facility a marriage is about to take place the 16t super structure engine that is the power pack and auxiliary winch is being coupled with the rotating platform a job that requires good teamwork between alexanda and vham Nate the task is made easier thanks to some technical refinements the power pack and rotating platform are fitted with automatic quick couplers for the hydraulic lines and there are two locating pins on the rotating platform they ensure that the hydraulic quick couplers slot exactly into one another okay moving forward now [Music] okay Alex is it lined up on your side Yep looks good hit the quick couplers make it necessary to connect the hydraulic Lines by hand this saves time when rigging the crane at the job [Music] site all that's left is to insert the Locking pins and the marriage is [Music] complete in the meantime the 600 L diesel tank and the hydraulic oil tank with the holding capacity of 300 L have been installed on the carrier of the mobile telescopic Crane and connected up some of the side panels have already been mounted too but the biggest component is still missing the driver's cab it's nearly 3 m wide and weighs about the same as a small car one ton with the driver's cab attached to the lifting beam maximilan Schulz and Daniel CLA lifted onto the carrier chassis using the overhead crane before setting it down they have to feed the connecting hoses and cables through the openings in the chassis while making sure that nothing gets trapped at the rear of the driver's cab the mechanics mount it to the vehicle chassis using shock absorbers these shock absorbers not only make it more comfortable for the crane driver they protect the electronic components inside the cab from excessive [Music] vibrations the mechanics then Bolt the front of the driver's cab to the carrier chassis electrician Oliva bents provides assistance with the next task there are a multitude of cables that have to be fed through to power the instruments electronic control units and monitoring systems as well as for the air conditioning system then there are the pneumatic lines for the foot brake the emergency brake and the parking brake this process takes over 3 hours afterwards Daniel cloa installs another mechanical component the steering linkage between the driver's cab and the running gear the carrier is now more or less [Music] [Music] complete the electrical and hydraulic components of the completed superstructure that is the rotating platform with coupled power pack are now subjected to a variety of tests these are performed form Med by test technicians tilo and otmar [Music] G the components being scrutinized include the ballast cylinders on the power pack when rigging the crane they're used to raise the ballast tray with the ballast blocks from the carrier so that the LTM 1750 has sufficient counterweight when performing a lift [Music] the first thing we need to do is start the engine so we can release the locking mechanism and extend the balasing cylinders then we check the pressure during extension if that's okay we retract the basting cylinders again and check the pressure during retraction it should be a maximum of around 300 bar okay you can start the engine [Music] before the actual test begins otaga releases the Locking cylinders they ensure that the ballast cylinders remain in their current positions then the test technician extends the bast cylinders tilo checks the pressure of the hydraulic oil using mon omers it's okay and the same on both sides looks good here now the test technicians retract the ballast cylinders the oil pressure is checked once more it isn't quite right Tito adjusts it to the desired value 300 bar everything's good once the Locking pin is reinserted the test is over the two test technicians still have plenty of other tests to perform on the hydraulic systems and [Music] electronics in order to test the carrier of the mobile crane they first need to start the engine the mechanics connect an exhaust gas extractor unit to to the exhaust [Music] pipe the diesel and hydraulic oil tanks have already been filled the only thing still missing is the ad blue an aquous Ura solution used to reduce nitrogen oxide emissions the tank of the LTM 1750 holds 60 L now maximilan Schulz can start up the 680 horsepower diesel for the first time checking whether the engine runs smoothly and revs up evenly isn't the only purpose though we have a number of test programs that put the whole carrier through his Paces we run through them one after the other first up is the radiator fan test we run the fan up to full power and check that there aren't any leaks the fan cools the engine coolant the charge a for the diesel engine the hydraulic oil and runs the air conditioning system none of the radiator connections are allowed to leak [Music] test passed no leaks test number two the [Music] steering everything's okay here too next to be tested are the hydraulic oil pumps fitted to the carrier [Music] engine they allow the crane to be operated in a limited capacity even without the power pack the super structure engine installed this means the crane can rig itself at the job site and install the power pack without external assistance as well Daniel cloa connects a monometer he uses it to check the pressure provided by the hydraulic oil pumps a quick Readjustment and this test routine is also completed [Music] mounting the wheels of the mobile telescopic crane is not a job that can be done by hand because each of the 18 Wheels weighs 300 [Music] kg but that's no problem for this special Tire forklift it enables mechanic maximian Schulz to fit the tires on the wheel hubs with [Music] ease the enormous tires have a diameter of 1. 5 M and are mounted on 25in rims they have a thread depth of 2.

8 cm and are pumped up to a pressure of around 8 bar each wheel costs around €2,500 so a complete set of of all nine axles adds up to roughly [Music] €45,000 the 10 nuts on each wheel are tightened by Machine the powered torque wrench which always tightens two nuts at a time supplies the necessary 600 nton M thanks to these special machines it takes two mechanics just 2 hours to fit all 18 Wheels the Hoist cable of the mobile telescopic crane is 700 m long and weighs 4 tons test mechanics tilo and otara now have to spool the enormous hoist cable onto the superstructure winch to do this they first Mount the cable drum in a spooling jig they attach the end of the 2 1/2 CM thick cable to the hook of an overhead crane and bring it to the winch installed on the rotating platform of the crane to which it's then bolted so this was so finished clamps are tightened now we have to go down and check the pre-tensioning the test technicians can't just spool the heavy cable onto the winch drum just like that otar Giza first runs it over a pulley and raises it up using the overhead crane meanwhile his colleague makes some other adjustments so and there's a breake on the spooling jig here that's pre-tensioned with a certain springload to provide a braking force of around 500 kg when the brake is applied the crane winch has to pull with a force of 5,000 Newtons to keep the cable taut during spooling the side pre-tensioning is important to ensure there isn't any loose cable on the drum which could result in the winch getting damaged if the cable is too slack on the winch and we pick up a load the load could suddenly drop down causing damage to the cable and in the worst case snapping it T's colleague otaru tensions the Hoist cable by raising the pulley with the crane he applies wax to the wind on the rotating platform this helps prevent the steel cable from [Music] corroding tilo starts up the winch on the superstructure of the crane spooling on the 700 met long hoist cable takes several hours in the telescopic boom shop the mechanics are preparing to slide the Boom sections inside each other inside of this telescoping section has already been greased mechanic Andreas gaus places slide plates made from a teflon-like plastic at the ends these banana plates prevent the slide plates from [Music] moving slide plates have already been installed at the bottom of end of the telescoping section 2 the mechanics now slide this telescoping section into the next largest T3 has to go inside TAA 2 the men have to be careful when maneuvering the overhead crane to ensure that the 15 M long 6ton section doesn't start swinging the mechanics continually check whether the telescoping section is sliding horizontally into the other or is in danger of twisting before TAA 3 can be completely inserted into TAA 2 the mechanics Mount slide plates on the inside of TAA 2 and fix them in place with banana [Applause] plates the slings are removed as they would get in the way when sliding the section the rest of the way in the men now suspend tea 3 from the chains at the back from the overhead crane and slide it all the way inside tea 2 once it's fully in the boom pin Springs out and locks tea 3 inside teet 2 only when all the telescoping sections have been slid into one another can the mechanics install the telematics system this hydraulic ram is responsible for extending the telescoping sections it the telescoping Ram is installed here there are two cylinders here that fasten the respective telescoping section once it's fastened this mushroom head is captured and pulled down by the yolk at the other end of the mushroom head is a bolt this bolt is released in this way the telescoping Ram can extend the entire system to the desired [Music] length the carrier of the mobile telescopic crane is complete the four hydraulic Outriggers used when the crane is in operation have already been mounted and are now deployed everything is ready for the superstructure to be installed [Music] it consists of the rotating platform and superstructure engine the power pack the massive structure weighs 26 tons the men use two overhead cranes to transport it to the [Music] carrier we have to be careful when operating the overhead cranes that we move slowly and in sync or we could end up knocking into the shelving or other overhead cres what follows is the trickiest part of the marriage placing the super structure onto the carrier because the holes in the sing ring attached to the superstructure must line up exactly with the corresponding holes in the bearing surface of the carrier we use these templates to make sure that the holes in the rotating platform and carrier match up by moving them around we can find the right position of the holes in the bolt pattern I can screw the centering pin in in this position we do the same up here on the rotating platform you can see that the holes don't match up like this I have to keep moving the template until I find the position where the holes align properly this position is right so I mark it with a pen the centering pin now has to go into the hole with the marking a job that requires fine control of the overhead [Music] cranes is it looking good on your side yes a total of 388 wasted expansion screws are now placed in the holes they're self-securing which means they won't come loose even under extreme stresses next mechanic Alexander Kona makes the hydraulic connection between the carrier and super structure it's now possible to operate the crane even without the power pack although in a limited capacity once the electronic control cables have been installed the marriage between carrier and superstructure is complete the 16t power pack must now be removed from the rotating platform again to make more space for completing assembly of the mobile crane [Music] the enormous telescopic boom of the LTM 1750 mobile crane is on its way to the assembly facility but before it can be mounted on the crane Alexander Corona and Patrick Elma first have to install the luing cylinders on the rotating platform each cylinder weighs 2. 5 tons they're 6 M long and have a diameter of 50 cm when the crane is in operation they raise and lower the telescopic Boom the mechanics have to work carefully when maneuvering the luffing cylinders into position to ensure that the 19 CM thick steel pins can be inserted and bolted into place afterwards once both Ling cylinders have been installed they're connected to the hydraulic system in order to raise the telescopic boom to an angle of 86° even under load they require an enormous oil pressure of up to 400 [Music] bar this here is the cylinder connection it regulates the pressure between the left and right cylinders so that they always operate the same if the pressure were different it would overload one of the cylinders resulting in catastrophic failure of the crane only one component required to complete the mobile crane is still missing and it's the heaviest the enormous telescopic boom weighs 35. 7 tons it's 16.

3 m long when retracted and 52 M long extended Patrick Elma and Alexander Corona need two of the large overhead cranes in order to mount the huge structure with their help they maneuver the boom to the mobile [Music] crane 3 minutes later the telescopic boom is at the mounting point on the rotating platform the installation requires a delicate touch so we're now moving the boom into position we have to get it exactly centered on the rotating [Music] platform we need to set it down on the rails here and slide it back while adjusting the tip left and right to get the boom positioned precisely in the middle so we get the pins in easily afterwards [Music] good become the Locking pins have to go through these brass bushings they have lubrication grooves machined in them that the men now brush with grease then the Precision maneuvering with the crane remote controls begins you still have space yeah a little yes okay I'm touching I'm touching too good we can put the pins in okay pins of this size can't be inserted by hand though it takes a special device and machine power are we in already yes good okay we're done Patrick Elma and Alexander Corona now have to attach the Ling cylinder to the telescopic boom here too they apply grease to the Brass bushings and locking pins they use the overhead cranes to lift up the luing cylinders then the pin insertion machine is used once [Music] more good are we in done [Music] yep once both of the pins have been inserted they're secured with Bolt s the mobile telescopic crane is fully assembled now it's time for the first of the function tests from the operator's cab industrial mechanic Patrick Elma starts up the LTM 1750s [Music] engine he performs the function test using the mobile cranes wireless remote control first he checks whether the Ling cylinders used to raise and lower the telescopic boom operate [Music] properly test number two the sing motor which must be able to rotate the super structure through 360° without jerking [Music] the third and final test involves the Crane's spom Patrick Elma checks whether it telescopes correctly all of the systems work flawlessly at least when not under load before being delivered to the customer the LTM 1750 mobile telescopic crane spends 4 weeks at the enormous Factory's testing ground being put through its Paces namely in all configurations that the customer has ordered for today's test the technicians have loaded 204 tons of ballast and mounted an over 30 m long lattice Ling jib on the telescopic boom they specifically want to check that the welds of the boom section hold even under maximum load before the test Foreman Ral ller and test technician and crane operator Stefan zaab discuss the plan I've attached the 31. 5 lattice Ling [Music] jib okay we have to extend all the telescoping sections to 92% so we can load the luing jib according to the test criteria then I need to lift 49 tons yes yes that's right the test begins the crane operator extends all three telescoping sections to 92% the telescopic boom is Now 49 M long including the luffing jib the total height of the crane is now 85 M Stefan zabia takes up the strain with the Hoist cable the load on the hook steadily increases we're now at 20 tons 30 [Music] tons now entering yellow zone and we have shutdown the technical term is load moment limit that's the moment when the customer can't keep going which means the load is too heavy but because we're doing acceptance testing here we can override it and push it to 130% so we can test the crane thoroughly I have to turn this key then it blinks up here and I can continue the option to override the system is reserved solely for the test technicians at the factory okay we've reached the test load of 49 tons and the crane is still standing the test with the 31.