Spotlight Feature Articles HIGH PROFILE- Liebherr JAN 18 | Page 2


A new class of technology

The VA Erzberg iron ore mine offered an ideal challenge for the new truck
In late October 2017 , Paul Moore went with Liebherr to the VA Erzberg iron ore mine in Austria for an introduction to the new T 236 100 t diesel electric truck , and quizzed Liebherr Mining senior managers on the technical argument for the design as well as its market entry potential class . The T 236 is the first 100 t truck which combines an oil immersed , 4 corner wet braking system with a diesel electric drive system . Other electric trucks that have been made in this class have diesel electric drives but are still using dry brakes . That will only allow them to do the retarding or if you like ‘ maintenance free braking ’ on the rear axle , which isn ’ t ideal in wet conditions . In wet conditions , with 4 corner retarding , you are still able operate our machine much more safely than by relying on rear axle retarding . Wet brake lifetime can be up to approx . 20,000 hours and beyond , dry brakes in the case of a lot of use can mean workshop time significantly more often . This is why many mining customers wanted a 100 t truck with wet brakes and why they asked us to develop one to get the maintenance savings on top of the enhanced safety . It also has an innovative , variable hydraulic system that lowers machine parasitic losses to provide maximum possible power for the drive system .

Liebherr last year launched the T 236 , a new 100 t class truck in an already crowded market , so it had to be a game changer in its technology offering and performance upside . It had already gone through an intensive product validation phase at Erzberg . The tests were designed to evaluate the product using several different parameters , specific function & performance tests for the systems , and structural evaluations . Extreme driving manoeuvres were also used to evaluate operator safety , load stability , and machine performance during this trial which was successful , and the truck during the IM visit was running through its first field operation trials at the mine .

What is new about the T 236 is that it has electric drive , traditionally confined to the ultraclass , and that it combines this with state of the art wet braking . With its IP 68-rated plug anddrive power modules it is also safer and more efficient from a maintenance point of view ; while the revolutionary in-line electrical power train layout minimises cable length . Finally , the ergonomic T 236 cab and the superior properties of the front wheel suspension system promote driver efficiency with superior comfort , safety , acceleration and handling for increased performance . But for the real insight , here is what senior managers Dr Joerg Lukowski , Executive Vice-President and Dr Burkhard Richthammer , Managing Director , Design and Engineering have told us about the new Liebherr Mining truck ...
Q Why the Erzberg mine as a trial location for the T 236 ?
BR : Erzberg has an interesting mine site set up for 100 t trucks in combination with the use of wheel loaders . The site organisation allows the wheel loaders to already have the material prepared at the loading spots , and the trucks are running more or less all the time without much queuing at all , meaning it was a good test site for the T 236 as we are expecting a high machine utilisation . The Mine blends the ore and uses lower tonnage , single row blasts for a selective mining process . The mine also has a number of challenging ramps reflecting the topography , with both uphill and downhill haulage cycles , and constant variation of grade . It also has very variable climate . It is an alpine mine active for more than 330 days each year and has continuous 24 hour operation . The climate conditions can vary from snow with temperatures of -20 ° C to summer heat , with in-pit temperatures that can reach 40 ° C . A particularly interesting climate profile is that in a matter of hours , it will intermittently switch between rain and sunshine . This all translated to an ideal challenge for our truck . Lastly , they run a competitor fleet of mechanical drive trucks making for a good comparison from that standpoint .
Q What is unique about the T 236 in an already very crowded 100 t truck market ? How did you arrive at the decision to go down this design route ?
BR : It ’ s a combination of the braking system together with the Litronic Plus Generation 2 AC diesel electric drive in that form and in this truck
JL : And don ’ t forget we have the other truck models , including the T 284 and the T 264 so have a lot of experience in applying advanced braking systems on those . But to go back to 2012 / 2013 at the start of this journey , we did an extensive market study that showed first and foremost mines were ready for a 100 t class diesel-electric truck , with the better acceleration and starting , and increased speed on uphill ramps . We started developing two 100 t model concepts in parallel on a feasibility basis ; and realised soon that the combination of wet brakes and electric drive offered the greatest potential . Moving forward to today , Erzberg have told us a big advantage of the truck is its adaptability and flexibility in their mine in that to some extent its systems , particularly the drive and torque curve , can be programmed to adapt to changing conditions and changing mine set-up over the months and years , such as new haul road layouts , particularly the ability to handle steeper or shorter ramps . So the T 236 is able to handle a wide range or working environments in a mine with the same high performance .
Q Can you go into more detail on the flexibility advantage from an operational point of view ?
BR : With the electric drive you are completely decoupling the engine speed with the speed on the rear wheels . There is no mechanical interaction anymore , which gives us the freedom to manage and change all the parameters as we want . Same thing with the retarding , going downhill we are able to adjust it required ,
International Mining | JANUARY 2018