The Unimog cab has some neat features including a Webasto diesel heater, two-way radio, warning light for tip cylinder, air suspended seats, and a heated windshield. Visibility is helped with high mounted headlights and daytime running lights.
On the front of the Unimog is a 16,000 pound hydraulic Warn Winch. In short, this Unimog is loaded.
The Utility Flatbed
I wanted to keep the rig as compact as possible while keeping the utility of the tipper utility flatbed intact. The platform of the tipper body is 8.75 feet long, 7.3 feet wide, and 15.8 inches tall. The new flatbed was to be eight feet wide by eleven feet long.
I decided to build a new tipper bed and integrate tanks for fresh water, grey water, black water and diesel into the bed itself. I also wanted to use 3CR12 as the material. 3CR12 is a very strong grade of stainless steel that is resistant to corrosion, forms well, and welds well.
The bed was constructed with two inch by four inch by three millimeter (.118”) thick rectangular steel tubing. In all but one place, strength was increased by using two pieces of two inch by four inch rectangular 3CR12. The longitudinal and lateral pieces lock together by each being notched out in the appropriate places. This creates an extremely strong structure.
The first two feet behind the cab is dedicated to holding the spare tire, a generator, and tools. The remaining nine feet would be an open bed with sides from the original U500NA tipper bed.
The Built-In Tanks
There could potentially be 2,000 pounds of fluids in my rig at one time. That includes diesel, gasoline for the generator, fresh water, black water, and grey water.
That being said, one of the amazing things about this rig is that the truck camper itself physically has no holding tanks. All of the fluids are stored in the Unimog’s bed or the truck’s tanks.
A regular Unimog has support beams under the bed holding up the bed. The voids between the longitudinal and lateral pieces of rectangular tubing (see photograph above) were converted into tanks for fresh water, grey water, black water, and diesel.
There are three separate fifty gallon fresh water tanks, forty gallons of black, and forty-five gallons of grey. There is also eighty gallons of diesel in the bed of the truck as well as the truck’s standard sixty gallon diesel tank for a total of one hundred and forty gallons of diesel. We also carry six gallons of gasoline for our Honda generator.
The diagram above shows the underside of the rectangular tubing skeleton covered with the lower trays for the tanks. Blue represents water, grey represents grey water, black represents black water, and green represents diesel. The top deck was covered with a flat sheet in a similar configuration.
In the picture above you see the upright section dedicated to holding the spare wheel and tire, tools, and diesel tanks.
With about 150 gallons of water and 140 gallons of diesel, I was satisfied. The weight was low and evenly distributed across the bed. I designed all the required plumbing connections, fillers, and breathers. I used quick connects where necessary for the camper unit that would occupy the rear nine feet of the bed. The camper extends past the rear of the bed by one foot and drops down one foot below the deck.
I placed a deck on top of the frame and made trays that were welded onto the bottom of the rectangular tubing frame. The top deck and bottom trays were made from a three millimeter thick 3CR12 flat sheet that was laser cut and formed.