Some innovative ideas never lose their appeal.
Take hovercraft. The 1950s and 1960s loved hovercraft. Several commercial versions of hovercraft like the SR.N4 Mountbatten class that moved millions of passengers between Calais and Dover (England) before the creation of the Chunnel. Hovercraft showed up in movies and advertising for decades, and developers found deep pockets from militaries around the world. Hovercraft still are in commercial use today, but a conservative estimate says they number less than 100.
Or how about examples from two ends of the commercial air transport spectrum? The timeless appeal of airships has never lapsed, and neither has the desire for supersonic transport. Commercial versions of these two concepts have tried, failed, and come back again and again. Like some version of Sleeping Beauty, believing someday their market will come.
Turbine powered cars, trucks and trains also seem like cyclical ideas. A lot of money was spent in the 1950s and 1960s to develop prototypes and even some limited production vehicles. The idea smoldered for years, occasionally returning in various forms to help rationalize hybrid-electric power systems.
Sometimes the ideas were truly before their time. Aerodynamic trucks have a wealth of patents dating from the 1930s to the 1950s. The market didn’t seem to care until briefly during the 1970’s fuel shortages. Then in the early 2000s, the freight market realized that better fuel economy really mattered as diesel price volatility became the norm. Regulations were adding equipment and cost to trucks that had to be offset by any means possible. Aerodynamics was easy pickings — adding a simple roof fairing to a truck could easily get a 10% fuel economy improvement. Aerodynamically shaped tractors were just a styling change away. Throw in some low rolling resistance tires and a skirted trailer and suddenly 10 MPG was not only possible, it was happening.
Which brings me to cabovers. I’ve written on the history of cabovers. They were the hope of the future in the late 1930s, solving several operational issues. Then when rules changed in the 1980s, the market evaporated in favor of traditional tractors with hoods. By about 2005, no one made a cabover for commercial use in the U.S. But now they are back again. European- and Asian-based companies have reintroduced cabovers to the U.S. market. Startups like Tesla and Windrose are just starting to make market headway with vehicles that might be considered more cabover-like than hooded.
In 2025, I watched a 200+ lb. driver climb into his BYD electric truck at the Greenlane, Colton, California charging station. The operative word in cabovers is “climb.” You don’t step into a cabover. I recall climbing into a Freightliner cabover in 1981 in Portland, at their R&D lab, an Argosy in 1999 at a U.S. truck show, and into a Renault Magnum at a truck show in Paris in 1998.
This is where the Windrose and Tesla Semi differ from the old cabover. You step into them, aided by coach doors. Entry is somewhat less vertical than found on traditional cabovers and the floor heights likely are somewhat less as a result of efficiency in packaging BEV equipment.
The term “coach doors” refers to doors that open from the front. They used to be called “suicide doors.” These doors have been around a long time. Like hovercraft, supersonic planes, airships, and such, coach doors cyclically come back into vogue.
I recently toured the Sequim, WA history museum in the Washington State Olympic Peninsula. Amid artifacts like a full scale mastodon, I came across a 1939 Autocar freight truck. Not only was the cab aerodynamically shaped, but that teardrop shape was enabled by having the doors open from the front. Coach doors. Go figure.
1939 Autocar in Sequim Museum Rick Mihelic
With a little bit of web-enabled research, you can find many examples like this truck’s doors. These trucks are prized by collectors now. Hunt through the US patent office and you can find examples of patents on coach doors. For example, #2084600, Automobile Door Construction, applied for in 1936, suggesting coach doors can give better access to interiors than front hinged doors. Or #1857696 Door of Road Vehicle submitted in 1928 showing a door hinged at the back.
Coach doors were common on higher end vehicles, a feature that made getting in and out easier since human bodies have legs. The fact that they opened into the wind was troublesome for some, and reportedly a “feature” for others. Mobsters reportedly liked that the wind kept the door open while throwing people out of their cars. John Dillinger’s purported favorite car, a 1933 Essex Terraplane, had coach rear door. Clyde Barrow loved his Ford V8 so much he sent Henry Ford a letter thanking him for making great getaway cars. It had coach front and rear doors. Wealthy and famous owners of iconic Cord automobiles loved coach doors. And many trucks had them in the 1930s. The 1960s Lincoln Continental’s signature coach doors distinguished it from other limousines. The ZZ Top Eliminator has coach doors.
Why did coach doors largely go into hibernation in commercial vehicles? Hooded truck structural designs require the front of the cab to be structural stout. The hood is loosely secured at its back and provides little strength to the cab. The firewall and A-pillars carry a lot of structural responsibility. So mounting door hinges at the front of the door to the bottom of the A-pillar seems an easy choice. Mirrors often are mounted on doors or A-pillars. This helps minimize vibrations. Door seals also are particularly challenging for trucks.
Nothing is more annoying on long drives than wind noise blowing through inadequate door seals. That wind likes to go into forward facing steps like the front edges of doors. Placing the rigid door hinges at the front of the door provides extra security to avoid coaxing wind through the door seals.
The reality is that doors are flexible. Like the wings of an airplane, making them inflexible would require much more mass and cost. Doors are structurally designed to be just heavy enough to do their job, and not more. It’s common for older trucks to have door sealing issues because over time and abuse, they have deformed slightly. Rear mounted hinges could accentuate wind issues.
Then there was the 1960s push for safety ignited by the book Unsafe At Any Speed by Ralph Nader, and Congressional panels on car safety. The book questioned a great many car company priorities or lack thereof. Nader wrote a good deal on how annual styling changes meant to induce new car buying often neglected engineering for safety. Turns out door latching, something we now take for granted, was a significant issue in 1960s cars. A few cases where coach doors were involved in mortalities didn’t help the story.
That was 60 years ago. The automotive industry has largely endorsed safety as a priority. Helped along by expensive litigations and tougher regulations. Latching has largely been removed as an issue by better engineering and materials. Although there have been recent questions about door handle designs.
Like the reintroduction of the cabover to the North American market, the reintroduction of the coach door is opening new doors on designs. Time will tell whether the designs are robust enough for freight haulers, whether the seals hold up over the miles and abuse, and whether the designs introduce unintended consequences at truck stops or facilities.
The market chooses winners and losers. Ten or 20 years from now, these coach doors could be the new norm.
Or not.
![Img 9401[87]](https://img.ccjdigital.com/mindful/rr/workspaces/default/uploads/2026/05/img-940187.vJq7SVGjUK.jpg?auto=format%2Ccompress&fit=crop&h=167&q=70&w=250)
