Santa’s New Jet-Propelled Sleigh Leaves Reindeer Unemployed

Hit the dole, Dasher, Dancer, Donner, and Blitzen.

byLewin Day| PUBLISHED Dec 12, 2022 8:50 AM
Santa’s New Jet-Propelled Sleigh Leaves Reindeer Unemployed
YouTube/Robert Maddox
Share

Santa's overdue to trade in his old ride for a new Christmas cruiser. How about a jet-powered sleigh? There's one out there.

The sleigh is the work of one Robert Maddox, a self-taught tinkerer famous for his madcap builds. Known colloquially as The Rocketman, his hobby involves strapping roaring pulsejet engines to everything from go-karts to motorbikes and even skateboards. If his work reminds you of Wile E. Coyote, that's no coincidence. The accident-prone canid is one of Maddox's prime inspirations, as The Drive learned in an interview with Maddox earlier this year.

The sleigh follows on from Maddox's earlier go-kart, known as The Beast. It features three large pulsejet engines mounted to the back of the tube steel frame, which run primarily on propane. In the place of the Beast's wheels, though, Maddox fitted skis, creating a jet sleigh to blast around on the snowy plains.

The sleigh doesn't look like it quite matches the 90 mph top speed of The Beast, but it looks plenty fast. Maddox notes that winter temperatures below freezing make it difficult to keep the engines running as the propane tanks get too cold. While some pulsejets can be difficult to get started, Maddox has no such issues with his designs. He relies on a mixture of diesel and propane to get the jets roaring near-instantaneously.

Pulse jets are perhaps the most popular type of DIY jet engine, largely for their ease of construction. They require no advanced machining to produce turbine or compressor wheels, nor the use of particularly advanced alloys, either. In fact, valveless pulse jets used by Maddox feature no moving parts at all. Instead, they rely solely on the acoustic resonance designed into the engine's intake, combustion chamber, and exhaust. This resonance effectively acts as a "valve" that regulates the intake of fresh air and resulting periodic combustion events.

Pulsejets get white hot when in use. However, they require virtually no service or maintenance over their useful life. In Maddox's case, though, he typically finds the sparkplug lead for starting needs to be swapped out on each run due to melting from the radiant heat. YouTube/Robert Maddox

Despite their simplicity, pulse jets aren't practical for modern aviation. Issues of noise and efficiency mean they're not as attractive as conventional turbojets and turbofans for most purposes. They remain most famous for powering the V-1 flying bombs of Nazi Germany, with their cacophonous pulsejet drone earning them the nickname "buzz bombs." Pulse jets have gained popularity among some recently, with researchers looking at applying the technology to simple decoys or drones.

If you want to make thrust on a budget, though, a pulse jet is a great way to go. As demonstrated by Maddox, they're clearly great fun as well, whether you're blasting along on wheels or skis. Just remember not to touch the engine until it's had plenty of time to cool down, or you've delivered presents.

Got a tip? Let the author know: lewin@thedrive.com