I have read the Magazine publication Overland Journal for quite a number of years and after reading the off-road trailer articles have often dreamed about how nice it would be to have an overland support trailer. But honestly, the planning juices really started flowing many, many years ago with a series that Four Wheeler magazine did with a drive across Siberia in a Ford F-350 and support trailer.
I am an avid big game hunter and travel to Montana for several weeks a year for fly fishing, camping and hunting with old college mates from from my former University, Montana State University. I spend more time in the Montana, Wyoming and Idaho wilderness then in my Engineering studies but with age I grew tired of sleeping on cold hard ground in the grips of a Montana winter in late hunting season. I also grew tired of the constant dis-organization and chaos of camping, fishing and hunting equipment strewn about in the back of my Land Rover. I want my gear stowed, organized and ready hitch up and go on a moments notice!
I sat down to outline the basic requirements and pencil out a rough estimate of what it would take to build a trailer that resembles the capability of the Horizon by Adventure Trailer.
My basis of design:
1/ Strong, rugged and built of quality workmanship and materials. (If I can’t afford to build it right then I won’t build it at all – PERIOD!)
2/ Slightly larger, and sturdier than Adventure Trailers’ product (I’m sure theirs is perfectly strong. ‘More strong’ is better, right?)
3/ Compatibility to support a team of hunters in below freezing temperatures for a minimum of 60 days (food, water, fuel, shelter and heat)
4/ To have greater overlanding capability than the tow vehicle – i.e. vehicle is not dependant upon the capability of the trailer.
5/ Fuel, water, storage, shore power, solar and wind power generation and refrigeration/ freeze capability
6/ Independent suspension (no axel to get caught on rocks and stumps).
Back of the napkin estimate for an upgradable unit penciled to be about $4000. A drop in the bucket to the $20k that Adventure Trailer wanted for their Horizon. Little did I expect that as the project got underway and I decided on some changes that my price tag would balloon way out of range of my initial estimate. Ah hell, you only live once…..
So, I sketched out my design:
Then the realization of how bad the economy really was had hit me with a lay-off notice from my (then) current job. After a week of sitting around home the boredom hit and I realized, what a great time to get a start on this project. I have to get all these ideas out of my head and start cutting up some metal.
Finally, a trip with utility trailer in tow, to Northwest Pipe and Steel to pick up a load of steel tube to begin fabrication of the chassis.
The work on the trailer was making great progress until a job offer too good to say no to came along. A few days later the movers were on their way to move me, my stuff and my trailer (now in its infancy) from my beautiful farm in Gig Harbor to the dusty hot Tri Cities, WA.
Priorities shifted from my trailer construction to the move and the start of the new job. I still continued to assemble the hundreds of parts and pieces to create this thing but construction came to a halt for about 4 months.
With the new job now on cruise control I could shift some focus back to the fabrication of the trailer. The design of the suspension was complete and taking shape. Everything was turning out wonderfully plumb, square and level. Heck, I had yet to even bleed on this project. Too good to be true?? Until (a lapse of my metallurgy studies perhaps) a last minute decision to add Longitudinal Stiffeners to the main members of the chassis. Damn, I warped the whole ‘effing’ thing out of shape! Plumb, level and square no more….
But wait, I’m an engineer, I can figure this out. 30 gallons of diesel fuel in an integrated tank just forward of the spindles = 220 pounds. 45 gallons of potable water in integrated tanks just forward of the diesel tank = 380 pounds forward of the wheel spindles. A spare tire and wheel of more than 160 pounds forward of all the tanks. Plus miscellaneous propane and jerry can tanks. All placed smack-dab in mid-span of the trailer (thus the referenced longitudinal stiffeners). Oddly enough, the warp in the trailer was a perfect camber right were it should be if I were building a bridge. And oddly enough the combined weight off all this “stuff” was the perfect weight to take the warp, ehem – camber, out of the chassis. WHAT LUCK!
My next big decision was about the fabrication of the main box. My dilemma…I’m perfectly adapted to working in steel, but aluminum?? I had not welded aluminum since high school shop class. Dilemma part duex, aluminum is exactly twice the cost of steel but exactly half the weight of steel. Cost vs. Weight. Recall my prior design requirement – If I can’t build it right then I won’t build it all -. Aluminum is the right choice. By chance, I found a well qualified aluminum fabricator working from a home shop with access to a sheet metal brake, mig welder with spool gun and a plasma table. I contracted with him to construct the box while I finished the chassis and suspension.
I completed all the steel work and sent it off to the galvanizer for its life-time self-healing finish (and I love the industrial look of hot-dip galvanize). My focus turned to the selection and procurement of the wheels and tires. I had always loved the tread pattern of the Interco Ground Hawg but never had an application for them until now. Ok, tire selection was complete. But what size? I want floatation for sand and mud. Wide is good. And how tall? Well a quick calculation of the height of the roof-top-tent floor reveiled that in order for me to not hit my head each time I walk under the tent that a 36” tire would be necessary. Thus the selection of the Interco Ground Hawg in 36x14.5 R16 was complete.
Wheels? I quickly found that you can not get a wheel to fit this tire that is pattered for a 6 on 5.5 trailer lug pattern! Crappity-crap… ok, custom is required. A phone call to Stockton Wheel in California and a check for $1350 later my fancy new bead-locked custom made Power Wagon wheels were on their way in a raw finish ( I wanted these galvanized too).
After receiving them back from the galvanizer I quickly realized my big screw up. The bead-lock bolt holes were all plugged up with zink. Chit! Now I have hundreds of bolt holes to drill and re-tap!
Time for bolt up and this project is going long and way, way, way over budget!
Fabricator is now done with the box and tent rack just about the same time I finished bolt-up of the chassis and suspension. Time to pick it up and install it to the trailer frame.
And guess what, the box made it onto the chassis with the aid of two chain hoists – just moments before the eye bolt pulled free of the roof truss which it was screwed into. Near Miss No. 1! Now time to mount the Stainless Steel side boxes. Uncomfortable at best in the now 100 degree weather of dead summer in Kennewick, WA.
These were really, really nice stainless boxes but it was apparent they had a few quality control issues. The major dimensions were not consistent between the different boxes which made mounting them a little more tricky then it should have been.
My trailer could finally see the light of day as I rolled it out of the garage to begin the installation of the miles and miles of wiring (ok, it seemed like miles and miles….).
And 14 months after the initial back-of-the-napkin estimate and sketch my overland trailer hits the road for a test of its suspension and handling characteristics. Everything worked just as it should. I could not be happier with the outcome of this project. Hope to see you all on the trails soon….
List of equipment and systems integral to the overland trailer:
LOA: 11 feet
HOA: 6’-7”
WOA: 7-feet
Weight (Wet): 2800#
Ground Clearance: 22-inches
Chassis: 2 ½” x 2 ½” x ¼” steel tube
Main Box: 3/16” Aluminum (formed and welded)
Side Boxes: 1/8” Stainless Steel
Wheels: Power Wagon 16” x 10” bead-locked (hot-dip galvanized) - custom
Tires: Interco Ground Hawg 36” x 14.5” R16
Integrated Diesel Tank - baffled (30 Gal.)
Integrated Potable Water - baffled (45 Gal.)
Propane: 2ea 10lb Bottles
Gasoline: 1ea 5gal CARB Jerry Can
Pressurized Water: Yes
Sink: Yes
Heat: Wallas 30D diesel fired (Duct to Tent and to Water Supply) - future
Hot Water: Kimberly Kampers’ portable diesel fired hot water pack - future
Refrigeration: Engel MT80 Refer/ Freezer
Stove/ Oven: Propane
Microwave: outdoor rated 800 watt
Energy Storage: 8D 250 amp-hr battery, 1200 watt inverter/ battery charger with automatic transfer switch
Power Generation: Trickle charge from vehicle, 2ea 33watt solar panels, 400 watt wind turbine, shore power connection
Suspension: Independent drag-arm w/ 3000# firestone air bags
Brakes: Electric
Leveling Jacks: Manual
Hitch: Multi-Axis
Sand and Bridging Ladders: 4ea
Compressed Air: Yes
Roof-Top-Tent: ARB Touring – Generation II
Awning: Foxwing - future
Storage Capacity: Aft Compartment – 43cf, Fore Compartment – 14.5cf, Side Boxes (combined) – 31.5cf , Tongue Box – 5cf
I am currently in the process of testing this prototype unit and setting up a business to build a limited quantity on an as-order basis (taking suggestions for a name too!) Email or call if you might be interested.
Cheers,
Curtis Bray
curtpb@hotmail.com