A remote controlled 1/20 reproduction of the French Berliet T100, the largest truck of the world at its time. Features 6×6 drive with pneumatic locking differential, steering, suspensions, front fake V12 engine, rear auxiliary engine connected to the compressor, and a winch, with building instructions.

Direct purchase of the instructions

PDF instructions for the Lego Technic Berliet T100 in step by step 553 pages / 500 mo PDF file. Rebrickable partlist (3173 parts). Preview of the instructions at the end of the article. Presentation Video (youtube).

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History

The T100 was the biggest truck at its time, with 5m high, 5m wide, 15m long and a weight of 50 tonnes. It was designed by French manufacturer Berliet in 1950s to transport heavy equipments for oil exploration projects, such in Sahara. The idea was to carry heavy indivisible mass avoiding to use many trucks to transport equipment, like motor, drilling and then to reassemble it, contributing to a better operation cost. Therefore, the truck was designed to handle 100t of material, with conception choice accordingly.

Two Berliet T100 600ch model, photos courtesy of Fondation Berliet

The first is the tire. With the help of Michelin, they designed unique tires which can handle the weight but with only 1kh/cm² of pressure, same as dromedary’s foot to not be stuck in the dunes. The T100 is powered by a 24l V12 diesel engine from Cummins, firstly in 600ch and then in 700ch. The drivetrain is 6×6 with optional front axle drive (6×4), but the side wheel can be powered when the other are free to move thanks to many locking devices. Each axle have a locking differential and there is also one between front and rear axle. The suspension are rather classic with rear bogies with leaf spring and torsion bar and front suspended axle with leaf spring and lever arm shock absorbers. The T100 was pretty high-end truck with cab air cooling and 6 aeronautic multi disk brakes, when the competitor, Kenworth have no brake on front axle. To finish, a small auxiliary 2 cylinders Panhard engine placed on the rear supplies oil pressure and electricity when the big V12 is not turning on.

 

The T100 was operaded in Algeria at Hassi-Messaoud and returns to France in 1981. Its ability to drive in sand dunes enabled it to participate in 1961-62, in the extinction of the gigantic fire at the oil well in the Gassi-Toui. I decided to reproduce the 700ch model, in order to present this engineer truck, when the France was one of the best competitor in oil field truck.

You can read more about the T100 history here, here and here (french). I thank The Berliet’s Fondation, especially Paul Piemontese who was the head of operation of the T100 in Algeria, who gives me lot of technical details about the T100 and its history.

Presentation

My Lego Technic version is in 1/20 scale, with 63cm lenght, 22cm width, 23cm height, and 3kg weight. It seems to be massive, but there is no many room inside to fit all the function, as the wheel is very big compared to the size, and the cab is small. On the beginning of the project, I wanted to reproduce the unique drivetrain of this truck, with the gearbox, optional front wheel drive and its abilities to power side wheel only. Unfortunately, I have not figure out to transmit the power to the wheel using Lego parts. Indeed, the torque and weight were so high, that the gearing and the universal join do not handle it. Then I decided to create onboard motor axle to prevent the parts to be damaged. To me, it was the good decision as I would not be able to fit all the function inside.

Functions

The model is equipped with 3 L motor placed on each axle, it drive the wheel with 16t spur gear, 12/20t reduction, and 8/24t inside the portal hub. The central rear axle is connected to the fake V12 engine placed on the front, with CV join and gearing. This fake engine is composed of moving axle, and not big cylinders. This type of building enable a strong torque with no cracking sound, with a good speed. The only limitation will be the weight and the motor torque limitation.

The front steering is operated by a M motor placed on the front axle, which drives a worm gear though a 24/24 clutch, which operated a rack and pinion. Unfortunately, the steering wheel is not connected to the steering due to the available room inside. I have not use portal hub from Lego to build the front portal hub as the pivot was to far from the wheel, which makes the wheel touching the wheel arch. Therefore, I have used a homemade building with CV joint which limits the steering angle but  fits the wheel arch. You can note also that  small rubber wheel is placed on the pivot of the portal hub. It is to avoid the wheel to camber with the weight. It enables the wheel to have a support where they can roll on and increase the rigidity of the front axle.

Each axle have a locking differential which connect both wheels of an axle with a driving ring. All the differential locking are operated in the same time, using a motor M which drive a compressor, and a switch valve. A clutch on this valve prevent to force on the structure when the compressor is powered. Then, the compressor rotation is transmit to the rear auxiliary fake engine which U-join in order to power it when the locking differential are operated. I have chosen to have only one operated valve for all the differential locking in order to use only one port on the sbrick, and then use only one sbrick.

The last motorized function, is the winch placed behind the cabin. It is operated by a M motor with 8/24 and 12/36 gearing, ensuring enough force to pull object on the rear ramp.

You can see 3D ghost view of all the mechanic below :

The rear suspensions are based on a bogie design. Each axle is connected with a big oscillating arm (which is a leaf spring in real). Multiple connecting rods hold each axle to avoid lateral and longitudinal translations. Each rear axle is equipped with torsion bar made with connecting rod and long axle. It gives a very sturdy rear axle which move in function of the surface and handle the weight of the rear platform.

The front axle is different from the real one due to part limitation. Instead of a leaf spring, I use classic shock absorbers. The front axle is connected to the chassis with a rubber parts, and hold in position with a arm and many connecting rod. There is no torsion bar on the front axle due to the available room (mainly because of the fake engine).

Design

On this particular truck, the design is as important as the function, that is I have started by making raw axles for dimensions, then the design with the bodywork, and then rework the axle and the chassis to mix together. I have tried to respect all the proportions, which leads to some limitation like the steering angle to not reach the wheel arches and the rear suspension travel to have the platform in the correct height. I have also reproduced the particular shape of the hood with angled side and top assembly with exhaust but also the iconic front assembly with its body panels. I also reworked many time the bodywork to have the less visible hole. It includes the side of the wheel arches with connector and joiner instead of letting the hole of the beam visible. But also a choice of orientation for some element, the use of panels, like on the cabin, and some tiles to hide the holes, especially on the rear platform. At the end, it gives a very neat design.

Regarding the openable element, the side cover can be removed, and the doors can be open. I also focused myself to fit all the functions in it in a relevant cable path, including the hose. That is why I do not want to have more than 4 functions to have only one Sbrick, but also to have neat cable path. Therefore, the operated valve and the hose are located on the left side. The compressor is located on the right side which gives space inside the fake reservoir to fit the cable from the front. The cable from rear are located under the platform, and all cables go in one hole above the Sbrick. To finish, Forwart-Sticker made the sticker for the front grill and the wheel center, which looks very good and distinctive. You can find the sticker sheet on his website.

Abilities

The model is operated with a Sbrick. The battery box switch is accessible from the left after opening a small box. The Sbrick enables to power the 3L motor of the drivetrain with a very good speed and a average torque. Indeed, I have not design this truck for trial truck, as I wanted to have a playable set with some nice functions, therefore a good speed. As I have not be able to put gearbox which handle the weight and torque inside, I prefer to increase the speed and decrease the torque. As the drivetrain is very sturdy, the only limitation will be the motor torque in trial truck condition. It is not possible to rework the axle with more gearing without removing the locking differential. Or the new portal hub from Lego must be used, which unfortunately I do not have( maybe for a future creation !). Anyway, I do not think heavy truck is good for trial truck in Lego, there are slow and heavy, it is preferable to use light truck with strong motor and simple drivetrain to have better speed and good torque.

Pictures and Video

 

English spoken video version of this article (Design Secrets : Berliet T100 on YouTube)

Purchasing the creations or the instructions

You can purchase either the whole creation on the website Buildamoc including the Lego genuine parts and building instructions in PDF, or just the building instructions on nico71.fr.

Want to buy this creation ? The Berliet T100 has been indexed to Buildamoc and is for sale. The whole package included the Lego genuine parts, stickers sheet and the Pro rendering PDF building instructions.

 

Building Instructions

 

As usual, I have made the instructions for this creation, and what a instructions ! The Berliet T100 in Lego are composed of 3173 parts which is the biggest creation I have ever done. The instructions is composed of a step by step 553 pages PDF, in a professional looking as Lego official one with hose and cable paths. I have also decided to create the instructions in 300DPI which enables to zoom more in, it was a pain for my PC but better for you ! I have also included in the instructions the Sbrick custom profile as well as a tutorial to install it.

Want to know if you can build the Berliet T100 ? The model has been indexed to rebrickable, check it !

(please note that you have to add a sbrick to the bill of material on rebrickable partlist).

 
You can buy the instructions with the following button for 15€. You can also buy other building instructions and get an automated discount, 15% off for 2 PDF, and 20% off for 3 PDF on the total). The automated discount is available for all the instructions for sale on nico71.fr.

See it on the shop :

After your payment, you will be redirected to a page for downloading your instructions, and will receive also the link to download by email. Please check the spam box and be patient to receive it. If you have trouble to download your copy of the PDF after payment or open the document, do not make a paypal dispute, please check your purchase history or contact me using the contact form. The link to download the instructions expires within 24h. Contact me if you have lost your instructions. Note that you can print it, but not copy or distribute. Thank you for supporting my work 🙂

Here is some preview of the building instructions :