Someone Turned A Fire Truck Into A Ridiculous Cube Camper With Crazy Thick Walls

Most modern RVs, even gigantic Class A coaches, make an attempt to slip through the air as easily as possible. In this era of higher fuel prices, every little bit helps save some cash at the pump. Here’s a custom RV that throws a huge middle finger at aerodynamics by being a 28-foot-long cube. This 2013 Spartan Gladiator started life as a robust fire truck chassis cab, now it’s an RV with 6-inch walls, an 8-inch roof, an 8-inch floor, and an awesome interior with Amish woodworking. It’s even more affordable than a factory-built Class A, too!

Many Americans put their RVs away for the winter. Aside from the fact that so many campgrounds close for the winter season, countless RVs aren’t really built for winter use. If you do use many RVs in the winter, you can expect frozen pipes, cold interiors, and other dreary, miserable things. This Spartan Gladiator conversion promises to be something different.

Many of the campers I’ve written about, including the ATC Plā 350, the inTech Luna, the inTech Sol Dawn, and others, have walls featuring insulation values of R7 or below. Now, there’s a science to insulation values, but to keep it simple, I’ll let the U.S. Department Of Energy explain:

An insulating material’s resistance to conductive heat flow is measured or rated in terms of its thermal resistance or R-value — the higher the R-value, the greater the insulating effectiveness. The R-value depends on the type of insulation, its thickness, and its density. The R-value of most insulations also depends on temperature, aging, and moisture accumulation. When calculating the R-value of a multilayered installation, add the R-values of the individual layers.

Installing more insulation in your home increases the R-value and the resistance to heat flow. In general, increased insulation thickness will proportionally increase the R-value.

How does this translate to RVs? Well, many factory-built RVs have good enough insulation that you could keep warm on a freezing day with the RV’s furnace or other heat sources on. But, if you try to camp in below-freezing temps with snow and ice everywhere, you’ll likely start to struggle. Things are worse if you’re like me and you love a vintage-style fiberglass trailer as some models are infamous for being light on insulation. My U-Haul wouldn’t work in a Midwestern winter and even a new a Scamp might struggle.

Unfortunately, as RV engineer Andrew Herrick wrote for RV Travel, you have no real way of knowing if an RV manufacturer’s R-value is accurate. For example, if your RV is built with foam block insulation but also has aluminum tube framing, the aluminum tubing will act as a bridge, allowing heat to bypass the foam. The manufacturer may claim an R-value of 10, but who knows because of the losses created with the aluminum tubing. Another manufacturer may claim R values above 15 but calculated that number through the use of a reflective foil, which isn’t an insulator.

Herrick notes that there is no enforced code or standard to test RV insulation values. His advice for winter RVers is to look for RVs with the thickest walls, floors, and roofs you can find in addition to the fewest number of slides. Double-pane windows, enclosed undersides, and heated tanks also help.

This Spartan conversion hits most of those requirements.

This Fire Truck Chassis Conversion

Many custom RVs are built out of old buses and some are built out of old ambulances. It’s not often I see one that started life as a fire truck chassis cab.

The chassis this RV was built on was constructed by Spartan Emergency Response Vehicles. In 1974, Diamond Reo Trucks, the combination of Ransom E. Olds’ Reo and C. A. Tilt’s Diamond T, filed for bankruptcy. As Diamond Reo folded up its operations in 1975, a group of company engineers decided to take on a bid to build a custom fire truck chassis for the FMC Corporation.

Diamond Reo vice president of engineering and marketing George Sztykiel gathered a team of former Diamond Reo engineers to build the chassis without any assurance that FMC would accept it. However, FMC liked what it saw and promised future orders. Sztykiel joined forces with Charles R. McManamey, the president of one of Diamond Reo’s creditors, fiberglass supplier Form-Rite, to form Spartan Motors. At first, Spartan Motors was a subsidiary of Form-Rite. As the company found success in its fire trucks, it was spun off in 1976 before going public in 1984. Spartan would later branch out into transit buses, RV chassis, delivery trucks, service bodies, and more. In 2020, Spartan sold off its fire apparatus division to REV Group and changed its name to The Shyft Group. Now, a Spartan RV chassis and a Spartan fire truck chassis come from two different versions of Spartan.

The Spartan Gladiator is a long-running and popular chassis that was introduced in 1983. The Gladiator chassis is known for its powerful engines, low steps, and spacious cabs. New fire engines and fire trucks riding on the Gladiator chassis and cab enjoy front, knee, and side airbags, side impact protection, and 360-degree cameras. In this case, the cab is no longer around. In its place is a 28-foot metal living space that looks like it could have started life as the cargo box for a straight truck.

Behind the grille sits a Detroit Diesel Series 60 straight-six diesel. The Series 60 ended production in 2011 and Spartan’s 2013 brochure does not include Detroit Diesel power. So, it’s likely the chassis itself is older than 2013. Depending on the exact spec of the fire truck chassis, the unit could be a 11.1-liter engine rated at 350 HP up to a 14-liter engine rated at 515 HP. This engine is backed by an Allison HD4060 six-speed automatic driving the rear wheels. I could not find torque specs from Spartan’s brochures, but even the least powerful variant of the Detroit Series 60 made over 1,000 lb-ft of torque.

Besides, the engine isn’t really why you’d buy this rig. The seller says the RV has an 8-inch floor, an 8-inch roof, and 6-inch walls. It’s unclear how the seller made the calculation, but they claim the walls are R21 insulated while the floor and ceiling are R38 insulated. Even if these numbers are wrong, the walls, ceiling, and floor are all substantially thicker than what you’d find in the typical RV. You can see how thick the walls are when you look at the windows in the cab portion or how deep the entrance door is into the wall.

In addition to the thick structure, there’s a wood stove plus a diesel-fired boiler and hydronic heater. The diesel heater helps warm the coach and the floor. The RV’s plumbing system is contained inside the coach, so the heated floors also heat the holding tanks and water lines.

Speaking of tanks, there’s an 80-gallon fresh tank plus a 100-gallon grey tank. The builder decided to go with a composting toilet instead of installing a black tank. The bathroom features a residential shower and the kitchen has a residential refrigerator. Things get pretty cozy in that kitchen as the coach is said to feature Amish-crafted cherry woodworking.

Additional equipment includes 2000W of solar, a 4000W inverter, 400 Ah, 24V lithium batteries, and a quiet air-conditioner. Not noted but shown in the pictures is the coach’s metal roof, a cabinet for tools, a tow hitch, and a party deck. It looks like this RV was built so that you could repair it while on the road.

Not Cheap, But Not Outrageous?

You get all of this for the asking price of $150,000. I won’t pretend that’s cheap, but you do get a lot more RV for your money than you’d get with many of the new coaches I’ve written about. And this one is not one that you’d have to park before the first snowflake falls.

There are a couple of downsides, of course. As with any custom RV, you aren’t going to be taking this to a dealer when it breaks. So, you’ll want to be somewhat handy or at least know someone who is handy. The seller also says that you’ll get 7 mpg down the road, and I believe it. Those Detroits sound glorious, but you’re throwing all efficiency out of the window by pushing a metal brick down the highway. There are larger diesel coaches that can get better fuel economy, but we’re still talking maybe 9 or 10 mpg, and you definitely aren’t towing anything while driving. Single-digit fuel economy is often the reality of Class A RVs; you have to pay to play! On a positive note, the seller says the rig has just 100,000 miles, so the engine has plenty of life left in it. Series 60s are common in the trucking world, and I’ve seen examples with over a million miles.

If you want to live out your square dream, the seller is located in Dixon, California. That’s not too far from California’s many picturesque National Forests, so you can try this bad boy out right away. It’s a bit weird, but it’s unlikely you’ll see anyone else at the campground in a rig like this.