There are a total of eight
roller coasters worldwide named Viper. While
cloning is common in the coaster industry - designing a new ride is very expensive - each Viper is different. All of the American versions are at
Six Flags-owned
theme parks, and the other two Vipers are in the
United Kingdom. Only the Viper at
Six Flags Great America is wooden, the others are steel coasters.
The oldest continually-operating Viper is at Six Flags Darien Lake in New York. Designed by Arrow and opened in 1982, it includes 3,100 feet of steel track and reaches a top speed of 50mph. The highest point on the ride is 121 feet above the ground, but the longest drop is just 75 feet. There are five inversions - a vertical loop, twin corkscrews, and a pair of boomerangs. Two trains hold 28 riders each, and the ride takes two minutes and thirteen seconds from start to finish.
Built a year before the one in Darien Lake, the Viper at Six Flags AstroWorld opened at the Houston park in 1989 after spending its first eight seasons with the moniker Jet Scream at Six Flags Saint Louis. A Schwarzkopf-designed steel coaster, it is 1,969 feet long and 90 feet high. There is just one inversion, but the ride reaches a respectable 50mph and takes ninety seconds. The two trains hold 28 riders each.
The only Viper east of the Rocky Mountains is at Six Flags Magic Mountain in California. Another Arrow coaster, it required one million pounds of steel and 600,000 tons of concrete to build, and cost eight million dollars. Unique when it was opened in 1990, it remains competitive with the newer, fancier coasters being produced more than a decade later. The coaster's 3,830 feet of track reaches a height of 188 feet, and the main drop is 171 feet. There are no fewer than seven inversions, and each of the three trains travels at speeds up to 70mph, completing the entire ride in just two minutes and thirty seconds. With 28 riders per train, the Viper can process 1,700 riders per hour.
The wooden Viper is found in Illinois at Six Flags Great America; built by in-house producers, it opened in 1995. A wooden twister, the track is 3,458 long and 100 feet high with an 80-foot drop. There are no inversions, but the two trains run up to 50mph through the ride, including down a 53-degree slope. Each train holds 30 passengers, and the ride takes 75 seconds - when everything is running smoothly it can handle up to 1,000 riders per hour.
One of two Vipers not currently operating, the steel heartline coaster at Six Flags Great Adventure in New Jersey opened in 1995 and closed after the 2000 season; since then it has been SBNO. Built by TOGO International, it is a short ride for a continuous circuit coaster - just 1,670 feet. It does reach a height of 89 feet, and the ride's top speed is 48mph. Steel rings around the track provide structural support and add to the ride's theming. The three trains hold 16 riders each, who experience negative g forces on the double-inversion heartline roll.
The other closed Viper is at Six Flags Over Georgia. Originally built in 1978 at Six Flags Great America and called Tidal Wave, it moved to Georgia in 1995. The Schwarzkopf shuttle loop coaster closed on 16 September 2001 - my own theory is that shuttle loop coasters are not as popular anymore. The very simple design sends riders down a hill, through a vertical loop, and back up a hill on the other side. After a momentary pause, the train drops back down the hill, goes through the loop backwards, and continues up the opposite hill back into the station. The Viper is 863 feet long, and the top of the 70-degree loop is 138 feet above the ground. The ride only takes 35 seconds, but because the sole train can only take 28 riders at a time, this Viper processes 1,300 riders per hour.
Across the pond from all of these is the Viper at Lightwater Valley in England. Moved to the park in 1996, it is a steel twister by Schwarzkopf and has no inversions. The standard train holds 12 riders. In Wales, the Viper is the only coaster at Barry Island Pleasure Park. A Galaxy-style ride, the steel coaster was built by Pinfari and has no inversions.
Sources:
http://www.rcdb.com/result.htm?searchtype=coasterquick&name=viper
http://www.coasterbuzz.com/