Eden Prairie, Minnesota, is as good a place as any to learn a hard truth.
This suburb of Minneapolis is largely indistinguishable from the other suburbs that border it ... except that Eden Prairie has an airport. Last weekend, that airport played host to an air show, which featured your typical air show goodies—World War II bombers, modern military jets, stunt pilots, etc. But the Eden Prairie Air Expo also had something very special ... the Eureka, one of only three passenger zeppelins operating in the entire world.
Which brings me to the hard truth. The Hindenburg disaster often gets saddled with the blame for ending the era of airships. Plenty of sci-fi stories have started with the premise, "What if the Hindenburg disaster never happened?" and ended up assuming that we'd all be flying around in totally awesome zeppelins instead of boring old airplanes.
Unfortunately, the real circumstances that led to the demise of the airship appear to be a bit more complicated. If there's one thing I learned from getting up close and personal with a zeppelin, it's this: There are some very good reasons why the airplane won the fight for humanity's hearts and ticket fees. Reasons that have absolutely nothing to do with the Hindenburg.
This is not to say that the Eureka isn't pretty neat.
Perched in a field near the end of the airport's main runway, it was easily the most noticeable thing at the air show. The Eureka is big. Bigger than a 747. It fills your field of vision in that sort of way that inspires you to turn your steering wheel towards it, even if there are ditches, and buildings, and several airplanes between here and there. That's pretty cool.
It also has some practical functions. Ground crewman David Fritz told me that the Eureka has been used for field research, helping scientists track pods of killer whales off the coast of Seattle. That's a job helicopters can perform as well, but the Eureka does it a little better—it's able to hover over the pods for longer periods of time while using a smaller amount of fuel, and it also has a bigger payload.
Zeppelins like the Eureka also have some big advantages over the common blimp. You're probably aware of the basic difference: Zeppelins have a rigid frame that the "balloon" is stretched around, and blimps don't. But that difference matters. Zeppelins can carry more weight, so their gondolas can be larger. More importantly, they're also quieter to ride in. Because the gondola is the only solid surface on a blimp, the ship's engines and propellers must be mounted directly to that. On the Eureka, the propellers are mounted above the gondola, fixed to the rigid frame. If a blimp is like riding in a motor boat, a zeppelin is like being on a cruise ship. Advantage: Zeppelin.
But what if you compare the zeppelin to an airplane? This is where things go downhill. We don't live in an airship-less world because the Hindenburg turned everybody into fun-haters. We travel via airplane because airplanes have some distinct advantages in cost, speed, and conditions of use.
I'll start with that last one. When I planned this story, I was hoping to be able to tell you about "My Ride in a Zeppelin." Unfortunately, that didn't work out. I was only able to climb into the gondola while the Eureka was parked. Why? The weather.
July 15 was pretty stormy in Minneapolis. It rained on and off throughout the day. There were a couple of brief periods of thunderstorms, and the wind was gusty. It's the wind that turned out to be the most important factor in grounding my zeppelin adventure. "An airship is like a big sail," said Corky Belanger, one of the Eureka's pilots. "We've got a square acre of fabric."
That "sail" means landings, loadings, and takeoffs are tricky on windy days. On a landing, Belanger said, the wind could catch the zeppelin and push it sideways, like a beach ball skittering across the ground. The wind also moves the ship while it's tethered down. The Eureka is 246 feet long. Not coincidentally, that's also the radius of the mooring circle that the ship forms as wind slowly pushes it around on it's little back wheel. All of that meant that the Eureka had to sit on the ground while planes were safely taking off and landing on the runway behind her.
Wind can also make a difference when a zeppelin is in flight. The Eureka has a top speed of 78 mph. But it usually flies a lot slower, crewman Fritz said, closer to 45 mph. Meet a 50 mph headwind, and suddenly your zeppelin is going nowhere fast.
Speed is, I think, a key to understanding why airplanes overtook zeppelins as the favored mode of air travel. "When we go form one airport to another, [the support vehicles] can keep up with the zeppelin on the road," Fritz said.
That's why the Eureka is popular as a tourist attraction, selling sightseeing flights for a few hundred dollars an hour, but unlikely to make inroads in the field of real transportation. Zeppelins are cool and all, but if you really need to get from Point A to Point B, you'll either do it faster in a plane, or do it cheaper in a car.
Finally, there's the issue of expense. I'm not talking about fuel, here. Zeppelins actually use less of that than planes do. Instead, it's the support staff that starts to get unwieldy. When the Eureka travels, Fritz told me, it travels with 13 ground crew members, 4 mechanics, and 4 pilots, plus guest service personnel. Remember, that's for a ship that seats 12. (The crewmen, mechanics and backup pilots travel by car.) A 12-seater airplane, in contrast, really only needs to take a couple of people with it, and have a mechanic or two standing by at the nearest airport.
Some of this could be fixed by infrastructure—if the world were full of zeppelin ports, then the Eureka wouldn't have to travel with it's support staff. But even once you take that into account, the zeppelin needs babied in a way an airplane doesn't.
You've probably seen old photos of zeppelin ground crews holding ropes to help the ships land. Today's ground crews don't have to do that anymore, Fritz told me, because the ships now maneuver with the help of rotating propellers that can change orientation and allow the ship to land like a helicopter. Instead, one of the primary jobs of the modern zeppelin crewman is to hang out on the ship, monitoring the weather and the zeppelin's ballast levels.
There must be somebody on board the Eureka, 24 hours a day, 7 days a week. Even on a rainy, windy day, when nobody was going to take the ship anywhere, David Fritz was sitting in the gondola alone, watching the monitors. The balloon of the ship is filled with helium, but also contains two ballast bags—bladders at the fore and aft that can be filled with air from the outside. While he's on duty, Fritz controls these ballast bags. If the ship needs to be heavier in back, he sets that ballast to take in more air. The ballast bags compress or decompress the helium, making the ship lighter or heavier than air.
"That's actually why there's somebody on watch," he said. "We're managing the pressure. If the rain were to stop and the sun would come out again, it would start to heat up the helium [expanding it] and then the ship gets lighter."
Without the constant eye of Fritz and colleagues, the zeppelin could start to rise up off the ground while still tied down. Airplanes certainly need maintenance, just like everything else. But being able to turn the lights off and walk away is a distinct advantage.
Ultimately, I came away from my visit to a zeppelin with two thoughts. First, it's a nice reminder that the world is pretty complicated, and it got to be the way it is for many reasons. Sure, the Hindenburg contributed to busting the zeppelins' bubble. But improved airplane engineering probably played a bigger role.
Second, impractical or not, zeppelins are still totally awesome.
See More: My friend Mollee Francisco-Heinle, who works for The Chaska Herald newspaper, got to the Eureka on a more zeppelin-friendly day and actually was able to go for a ride. You can check out her photos, and watch a video of her zeppelin flight on the Chaska Herald website.
Photos by Christopher Baker.
Published 8:02 am Thu, Jul 21, 2011
Culture, Engineering, Everything Happens in the Midwest, Fulfilling Childhood Dreams, Technology