Liebherr LR 11200 Crawler Crane


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Liebherr LR 11200, picture 1

Features

Electrical functions:

  • Left and right crawler track forward - stop - backwards
  • Five winches, independently driven
  • Revolution of superstructure
Pneumatic functions:
  • Pump driven by 9V motor in the chassis
  • Four pistons act as supports
Mechanical functions:
  • Clutches to disconnect the winches from the motors
  • Model can be taken apart into 68 different modules


Introduction - Modules - Crawler Track Chassis - Superstructure and Winches - Boom System - Counterweight - Hook
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Introduction

The 11200 type is one of the largest crawler cranes Liebherr has built so far. Currently there are only two of them working worldwide - both for the same Japanese contractor. These machines feature a different color scheme than I used on my model. Because it contains a lot of green and blue, and LEGO does manufacture their parts preferably in other colors, it was not possible for me to copy it.
My model features the same functions than the original machine. There are different winches, a revolving superstructure, working crawler tracks and pneumatic pistons which are used to support the chassis during erection.
Overall height of the model is more than 2.1 m = 7' - from ground level up to the top of the main boom. It should have been able to lift up to 5 to 10 kg as far as the figures go, but the construction of the derrick boom reduced that to about 2 kg. When testing it with a bigger load, the derrick boom nearly collapsed and I had to reinforce it.
This model is not perfect to scale and some details are not the way, they are in the original machine. This, and the fact of the insufficient derrick boom make me think of a second version which will follow some day.

Liebherr LR 11200, picture 2Liebherr LR 11200, picture 3Liebherr LR 11200, picture 4

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Modules

The real 11200 can be divided into several modules to make transport easier and to select only the parts needed for a specific lift. My model can be taken apart into modules too - because of the same reason as mentioned when talking about the original.
There are 13 modules for the chassis, 11 for the superstructure, 21 for the counterweight, 22 for the booms, including the hold back lines, and one hook - equals 68 modules in total.
The pic below gives you an idea how the different modules look like and how much space they need.

Liebherr LR 11200, picture 5Liebherr LR 11200, picture 6

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Crawler Track Chassis

As mentioned above, the crawler track chassis consists of 13 modules. First, there is the center module with the lower half of the turntable. It houses a 9V battery box and a 9V geared motor which drives a Pneumatic pump. The electric wires are also connected to the center module and go from there to the different motors.
Attached to the center module are two crossmembers which feature two Pneumatic pistons each. They are used to lift and support the center structure during erection. Air comes from the above mentioned Pneumatic pump. There are two additional air hoses which go to the end of the superstructure. They were used if there was a counterweight waggon (which will follow in the second version - I think).
Attached to the crossmembers are the track frames, each consisting of two parts which are bolted together. The rear half of a track frame houses the drive motor, while the front one features a plate with the Liebherr logo.
The track frames are made of two layers of plates which are connected through crossmembers which itself act as bearings for the geartrain of the crawler drive.
Finally there are four parts which act as walkways around the turntable and two ladders to reach this platform.

Liebherr LR 11200, picture 7Liebherr LR 11200, picture 8Liebherr LR 11200, picture 9
Liebherr LR 11200, picture 10Liebherr LR 11200, picture 11Liebherr LR 11200, picture 12

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Superstructure and Winches

The superstructure is the heaviest part of my crane model - it houses no less than seven motors. There are two new 9V motors, acting as swing motors, and five old 9V motors, one for each winch. The five winches can be divided into two hoist winches for the hook, two luffing winches for the main boom and one luffing winch with two drums for the A-frame. (The A-frame is the yellow two-parted boom where it says 'Liebherr LR 11200'.)
Like in real, the superstructure consists of two modules which are bolted together, to reduce weight and dimensions for transportation. The hoisting winches I and II as well as luffing winch I are located in the front part while luffing winch II and the luffing winch for the A-frame are in the rear module.
There is a clutch in the geartrain of each winch. Opened it allows the drum rotating freely so that the string can be unreeled quickly.
As mentioned above, the A-frame consists of two parts where one part is a module for itself and is bolted with the same pin as the derrick boom to the front part of the supperstructure. The second part of the A-frame houses the sheaves for the luffing mechanism. On the rear module of the superstructure and on the A-frame are two times eight sheaves each. This means that you have two pulleys in parrallel, each parted sixteen times. They are used to lift the derrick boom.
Attached on the left side is the operators cabin. There are walkways around the superstructure which lead to the main service points.

Liebherr LR 11200, picture 13Liebherr LR 11200, picture 14Liebherr LR 11200, picture 15
Liebherr LR 11200, picture 16Liebherr LR 11200, picture 17Liebherr LR 11200, picture 18

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Boom System

The Liebherr LR 11200 is equipped with a derrick boom as a standard option. Optionally, a luffing jib can be mounted too. I didn't build it because of a lack of parts and a lack of room height.
The two booms are divided into several segments. The main boom has a pivot segment and a head. Between these two parts are a varying number of standard mast segments. My model features four mast segments. The derrick boom features a pivot segment, a head segment and always two mast segments.
The dimensions of the segments of the main and derrick boom are the same. In reality there are different dimensions. My solution allows it to use the model without a derrick boom (can be done too in real) and therefore use the two segments of the derrick boom to extend the main boom.
The segments are bolted together with Technic axles. You can see the connections at the line where the color of the boom changes.
The pivot segment of the main boom has an open frame on its upper side. This frame is used when a luffing jib is attached to the boom. Then it houses an additional winch which is used as luffing winch for the jib.

Liebherr LR 11200, picture 19Liebherr LR 11200, picture 20Liebherr LR 11200, picture 21
Liebherr LR 11200, picture 22Liebherr LR 11200, picture 23Liebherr LR 11200, picture 24

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Counterweight

A maximum of 2.5 kg of counterweight can be added to the superstructure. It is placed on the counterweight frame.
There are twenty containments, each weighing 0.125 kg. To achieve this weight, I filled the containments with granulated tin. The counterweight parts can be stacked up and feature four Technic pins to attach a lifting belt.
Up to a reach of 0.7 m and without a load on the hook, no counterweight is needed. This is because the derrick boom act as counterweight for a part of the main boom and the superstructure with its seven motors act as counterweight for the rest. If the main boom is lowered to the horizontal, counterweight up to about 1.5 kg is needed.

Liebherr LR 11200, picture 25Liebherr LR 11200, picture 26Liebherr LR 11200, picture 27

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Hook

The hook uses ten sheaves, like the head segment of the main boom. This way, a pulley parted up to twenty times is used to lift the load. Because the ten sheaves have to rotate with different speeds, I didn't fit them all on the same axle. There are two sheaves on one 2-unit Technic axle, so they use together one unit. The other unit is used to support the axle with two 1/2-unit Technic liftarm pieces. This solution is better than mounting all the sheaves on one axle, but it could be even better. A possible solution was to bore out the cross shaped holes for the Technic axles. I haven't done this because I don't like to alter LEGO parts.
The hook itself is connected with a threaded axle to a crossmember. This allows the hook to rotate around a vertical axis. The crossmember is attached to the hook block with two pins, allowing it to rotate around a horizontal axis.

Liebherr LR 11200, picture 28Liebherr LR 11200, picture 29

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