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20 years in the Amusement industry

Part 14: Thunderblooper -- Kings Dominion’s King Kobra

Sometimes I have this terrifying nightmare where I am hanging upside down on a stuck train inside a loop on a roller coaster, with nothing holding me in my seat but a single lap bar.

Then I wake up and remember this was not a dream for 24 or so people on Kings Dominion’s King Kobra in 1983, but 10 minutes of terrifying, trouser-soiling reality.

The King Kobra (also known by its generic manufacturer’s name “Shuttle Loop” or just “Looper”) was a Schwarzkopf-designed, first-generation steel launch coaster. It was installed in 1977 where the Anaconda lift hill today sits on the banks of Lake Charles. I do not know the politics or finances behind the design or purchase of the ride – only that by the early 80’s park officials may have been having second thoughts about the whole thing.

While modern launch coasters utilize “maglev” style linear induction motors to safely and reliably launch coaster trains (such as Volcano, Flight of Fear and that Italian Job coaster where Diamond falls used to sit,) the King Kobra (a “man’s ride” according to many maintenance employees) used instead a reported 90,000 pound weight inside the silo that supported the highest incline at the south end of the ride.

That massive steel-reinforced concrete weight was attached to a huge, 50mm steel cable that wrapped around a “bull wheel” (Also called a flywheel, really a giant winch) under the station, concluding at the other end attached to a solid steel “push cart” that closely resembles the Martian rover.

The launch was fairly straightforward: When the operator pushed the start button, the brake released on the bull wheel, and the weight dropped to the bottom of the silo. This action in turn caused the push cart at the opposite end of the cable to “push” the train out of the station from zero to about 50 mph. If the electronic photo sensors at the end of the launch zone sensed the train was at proper speed, then the train roared through the almost 50-ft diameter loop and up the 138-ft incline, where it rolled to a stop (giving riders a precious 2 or 3 seconds of weightlessness), before roaring backwards back down the hill, reverse through the loop. The train raced backwards through the station, where it was slowed by a short drift up the opposite incline before it settled back in the station and jogged by the operator into loading position.

While the train was in operation, the 45-ton weight was winched by the bull wheel back to the top of the silo, and the push cart made a loop on a steel track under the station, where it emerged at the rear of the train after it parked and unloaded. Its sharp hardened-steel nose parked comfortably inside a notch in the rear car, ready for the next launch.

Purists and physics majors may recall the King Kobra loop was not a pure clothoid loop like those seen on modern steel coasters, such as Shockwave or Anaconda. It was presumed this was intentional – the more “round” (or less egg-shape) the loop, the higher the G-forces. This was a strong yet undetected selling point, leaving riders more shell-shocked then normal without them realizing exactly why as they stumbled off the ride. It was a shrewd design move, not I assume an engineering blunder.

Sometimes the train failed to make full speed – this was called a false start, and usually the brakes caught the train before it got to the loop. In this case that extremely heavy train had to be pushed back to the starting position and another launch attempted. Rain, ultra-high Virginia humidity, an unusually heavy train or unusually cold temperatures contributed to false starts. If the brakes slowed the train but failed to completely catch the false start, the train would merely drift halfway up the loop, then impotently drift backwards back down to the station, where the operator would park it and start over. Still, a false start had to be called in to maintenance #257: “Be advised there was a false start on the King Kobra.”

On the other side of that coin, many riders speculated if the train ever “rang the bell” by bumping the rubber stop at the very top of the high incline. Only a couple times, when the ride was built and when the counterweight and speed were being adjusted did the train go to the very top of the hill. No, it did not break through the stop and dangle the lead car off the end, so put that ancient rumor to rest.

The ride was a mechanically complex monster, especially the electric-over-pneumatic-over-hydraulic brakes, which were notoriously fickle and needed constant adjustment. Many operators recall maintenance guys showing up and holding up a launch while they could loosen jam nuts, adjust the brake down a half-turn, bleed air off the brake, then tighten the jam. It was laborious and frankly a pain to go down there two or three times a shift to bleed and adjust those bloody brakes – and it seemed like there was a hundred of them to adjust.

This ride was explosively and painfully loud. At the launch ear plugs were required under the station, as the sudden scream of that massive cable unspooling against the equally massive bull wheel was like standing beside a space shuttle launch. In fact, when the ride left KD and went to Ocean City Maryland the launch violated a noise ordinance, and had to be shut down.

When the ride was purchased by KD, Schwarzkopf officials reportedly swore the train could never, never, never stick upside down. They claimed the design of the braking system and the shape of the loop could never tolerate a stuck train. But, according to the opening paragraph of this article, you know that was bullshit. Around 1982-83 (I can’t remember the exact date) the train experienced a false start, went up into the loop … and stuck there, perfectly and delicately balanced, upside down.

In those days of pre-standardized shoulder restraints, keep in mind those riders were suspended upside down by only a single padded bar against their laps.

It had to be terrifying. A “code-one” (life or death situation) was called in – one of only 5 code-ones calls I recall in my 20 years at the park (the others occurred at the Galaxie coaster, the Eiffel Tower, the Schockwave, and White Water Canyon). Two maintenance guys who happened to be in the vicinity raced to the loop, grabbed a 6-foot pinch bar that just happened to be in their truck, and scrambled up the enclosed ladder that circled the outside of the loop. One of them, a guy named David, reached the upside down train, inserted the pinch bar behind the lead car, and with surprisingly little effort pushed the train out of the loop, where it backed out and down to the station like nothing ever happened.

Arriving about 15 minutes later, I recall many riders sitting in a daze on the loading platform, waiting for an ambulance and to give their statements to Loss Prevention. It was like the Atlanta train station scene in “Gone with the Wind.” It was a terrible moment, but a fluke; a one-in-a-million freak occurrence that no one could ever have anticipated. Thankfully no one was injured, the park handled the situation with their typical exceptionalism, and after being shut down for a few days the ride was back up and running, with no decrease in capacity.

Even though the stuck train was a fluke, by 1986 KD decided to let the ride go. It was dismantled and assembled at Jolly Roger Park in Ocean City, Maryland, but since it violated the noise ordinance it went to Alton Towers in England, where I heard it violated a height ordinance. It currently sits practically unused as “Katapul” at Hopi Park in Sao Paulo, Brazil, where spare parts are almost impossible to locate anymore.

King Kobra – the ride gave little respect and got none back.

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