Liebherr R974B Litronic tracked excavator

Liebherr

Liebherr is a group of companies with activities throughout the world. Liebherr technology is firmly established in the world of building construction and civil engineering. Its program of construction machinery includes full-line offerings for construction cranes, mobile nd crawler cranes, hydraulic excavators, mining trucks, hydraulic rope excavators, wheeled loaders, crawler tractors and loaders, pipe layers, concrete mixing plants, and truck mixers.
Liebherr offers a range of hydraulic excavators comparising 24 models. There is literally something for everyone: from compact excavators starting at 53 kW through standard, medium-sized and larger machines all the way up to special-purpose excavators for the mining industry, which weigh in at 577 t.
One of those large excavators is the R974B Litronic. Off this heavy machine I've built a LEGO model. With it's weight of approximately 80 tonnes it suits very well on my lowloader vehicle which I've built a few months before.

Thee LEGO-model

Excavators are always interesting to build and that's the reason I started to build this Liebherr. A few years earlier I already built a CAT 375ME, but this time I wanted to take it on different. That CAT was more a static model, apart from the swinging mechanism.
My aim was to create a fully operational machine. The only thing which is practically impossible is to drive the machine electrical. So that's why I remained this undone. As LEGO has no hydraulics and the pneumatic cylinders are far too small for a 1:13 model, I really had a problem. However, when I use ropes instead of air, you've solved this problem very quickly.
I already had some experience building excavators, so I knew this model would succeed. But it seems a very complicated machine to build. First you must think about where to start exactly. OK, with the undercarriage, but the machine itself, the superstructure, is not very simple to construct. I had already some experience with crawled excavators, so I knew I would succeed with this model. But it seems very difficult where to start with. Of course you first construct the undercarriage, but the actual machine, the upperstructure, is very difficult to build. My aim is to build a model as precise as possible. Actually that's a requirement. From Wynmalen & Hausmann B.V. in Veenendaal NL (the excavator department of Liebherr Netherlands) I got the necessary information. I also asked for info at Liebherr in Germany. After some research work I found some nice pictures in several books about heavy equipment so I had enough info to start with this model.
The undercarriage is very solid. It's supplied with a heavy frame so it's impossible the machine would sag. The crawler are supplied with two lines of wide Technic crawlers on which I've put 1x6 plates. These gives the crawlers a more massive look and it just looks better at all. Unforunately I haven't done this to my CAT D9R dozer. In the undercarriage lays the drive of the turntable. This drive is the same as in my Liebherr mobile crane.
A flat floor is the base for the superstructure. On this floor a solid frame is mounted. The necessary Technic beams takes care of the sturdiness. In the back part of the machine lays transverse the real working V8 engine. As a supplement I use the Fyber-optic system. The engine is driven by one 9V motor. The ballast at the back can be separated, as well as the hood. The exhaust pipe is situated in the back.
The operator's cab can also be separated. Namely, it's possible to rebuilt the machine into a front shovel. This machine has a operator's cab which is placed on a higher level. In the upperstructure there are two 12V motors (from trains) which serves the digging arm. This time I used many 48 teeth gears in the drive. In the last step I've put a reel. The end of the rope is tied up on the digging arm.
Making a digging arm is a very complicated matter. The arm is round shaped so you have to work with staggers. First I made a drawing of the shape. Then I blowed it up into 1:13 in my computer. After that I made a flat dummy of the arm. This dummy is easy to rebuilt into the actual digging arm. Finally I made the whole arm. In the arm, I wanted to build the drive for the stick. This drive is just like the first one: with a reel. In the stick I placed the drive for the bucket. Here I didn't used a rope. In that case it would not operate well and, b.t.w., it's not necessary at all. If you looks good on the pictures, you can see those large gears in the stick. On the same axle I put two Technic liftarms which are connected to the bucket.
No, the bucket is not built of LEGO. It could be, but then it will not be possible to dig with. A bucket of LEGO-elements would be too weak so it will break. The bucket is made of aluminium. It's very light and it's looks very well. I have used the same bucket for the CAT excavator which I built a couple of years earlier.
The excavator is transported on the big red Scania which you can see on another part of my website. I've also put it onto a semi-lowloader, a yellow Scania. So you've seen the excavator before if you are a regular visitor of my website. But now you've red the whole story about this model and you've seen some stand-alone pictures of the machine.

A model like this seems to be a source for inspiration for others. Evert van Wichen also built one a few years after but his machine is a Liebherr R954B Litronic. I has the same proportions.

Other data

Length:	65.5 cm
Width:	22 cm
Height:	31.4 cm
Track length:	40.2 cm
Construction:	about 3.5 months
Date:	December 1999 - March 2000

Picture taken from Photos TP

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