Franna is an Australian crane manufacturer specialized in pick and carry vehicle. Terex acquired it in 1999.
The AT20 is a mobile crane with a 20t load capacity and pick-and-carry capability. It is one of flagship of Franna and it was recently upgraded to an AT22 model with a 22t load capacity.
You can find more infos and specifications of the real machine here : http://mightycranes.com.au/franna-at20-specifications/
The AT20 is the third Franna crane I build. I previously did the MAC25 and AT40 (click on the name to see the post).
The AT20 is on my to-do since 2016 however only the release of XL actuator in the Liebherr 9800’s set made it possible. The extra length of these actuators allow having a realistic range of movement for the erection of the crane.
All image are available on FlickR
The MOC is 15,6 x 51,1 x 19,2 cm (or 19,5 x 72,6 x 24 studs) and the hook reaches an height of 65 cm.
The truck is build on an articulated chassis. The front part accommodates the cabin (with seat and controls). It also supports all the crane stuff like the mast and actuators.
A rear hand-of-god gear actuates the articulation via the large turntable. Moreover the position of the HOG allows operating it even with the crane loaded.
The rear part includes a 6 cylinder (Mercedes, but I lost my stickers) engine under the hood. The fake engine is functional and is actuated by the wheels. The truck is all wheel drive with no central differential.
There is also an air filter and an exhaust pipe present on the bodywork.
The main mast is installed on top of the cabin. It has an enlargement to fit the width of the actuators.
A gear at the extremity allows the extension of the crane and a simple locking mechanism prevents it from retracting when in charge.
The winch is installed at the base of the crane and is also manually operated.
In addition to the crane operation and chassis, the AT20’s MOC has 3 options inspired by the real machine.
- Firstly, the forward lifting beam allows lifting larger load. It is install at the forward end ot the truck.
- Secondly the main small hook can be attached on the mast and allows the install of the larger hook for heavier load.
- Thirdly the rear handrail are removable.
It is possible to build the AT20 in other color scheme with the existing LEGO parts.
In the picture below (3D render from Studio) you can see the White & grey “Franna Terex” livery and the Red & Black “Mammoet” livery. They are based on existing AT20.
Instructions for all these 3 variant are available on https://rebrickable.com/users/Superkoala/mocs/
Thank you for reading !