★ Komatsu D155S Crawler Loader

B-Model for the LEGO CAT D11 42131

Let me introduce you to the biggest Crawler Loader ever built!

➠ Built only from parts of LEGO CAT D11!
➠ no additional parts needed!
➠ Full RC
➠ uses C+ Hub and PU Motors
➠ All functions work directly and simultaneous!
➠ no waiting for the transmission to shift!

★ Instructions

• • 483 Steps on 296 Pages
  • Easy to follow and clear 
  • Still challenging on some points to make the build as fun as possible
  • modular building / building in submodels
  • Includes color coded wiring for the motors
  • Includes how to set up “Controlz” app to operate the machine
  • Of course it also can be operated with Brickcontroller 2 App

(Lego Control+ app does not work. It can be driven and you can raise/lower the bucket with CAT D11 interface on C+ app, but not tilt the bucket, as one Motor is used for transmission on the CAT D11)

★ Features / Size

• Powerful driving / steering
• Raising and Lowering the Bucket
• Tilting the Bucket
• Openable doors
• Running V10-Engine
• Easy access to change batteries
• Length:     46cm
• Width:       24cm
• Hight:        25cm / 40cm when bucket raised
• Scale:       1:17 (fits all big scale trucks like Arocs 42143)
• It can load the Volvo Dump Truck with ease

• A little History of the Komatsu D155S:

Komatsu realized in the 1970s that it needed larger bucket volumes for loading. The CAT 983 had since it’s market appearance in 1969 a more than 4.0 m³ bucket (which is way larger than today’s 973 D has). With an operating weight of 32 tons, the CAT 983 is already a big hunk. Komatsu took things up a notch with the release of the D155S-1 in 1977. To improve productivity on job sites, it was important to reduce the number of loads on large dump trucks. Many sites had switched to dump trucks of up to 32 tons, and the development of large loaders had fallen behind. 

At over 42 tons and a 5.0 m³ bucket, it was then and still is to this day, the largest loader crawler ever built in the world! On top of that, the 350 horsepower was necessary to make it comfortable in its terrain. It was also thirsty. However, it was soon realized that the colossus was a real chain eater. More than 40 years ago, such monsters were in use in Tyrol during the construction of a large dam. Witnesses at the time reported that the undercarriage and running gear had to be replaced every year. It did not manage more than 2,000 operating hours. From the 42 tons downright ground, especially the guide wheels in front, there is the main load. Because when the bucket was so really full, she became very top-heavy. Hence the additional weight at the rear- as seen in many pictures. With such loads, the last order was to drive back and forth and let the trucks maneuver. The work on the dam was enormous, during construction the largest sieve house in Europe was operated there and delivered an hourly output of over 1,200 tons! There were no improvements made over the years on the D155S. Production finally ceased in 1989, and to date 234 machines have been produced and sold worldwide, 32 of them to Europe. 

Since the 90s, wheel loaders came more and more to the fore. Faster, more efficient and less expensive. The theme around large crawler loaders was over…

But they still are one of the coolest machines out there and still in use in some places.