Throughout 1997, the park's 'Fantasy World' area was closed and all its former rides removed, except the Black Hole. Details about Oblivion were not revealed until March 1998. The "SW4" codename stood for "Secret Weapon 4", after Nemesis' codename, "SW3". Oblivion's opening was accompanied by a large promotional campaign, including appearances on Blue Peter, news channels and cereal boxes. Prior to its opening, memorabilia including its own brand of deodorant was available to purchase. The total cost to construct the ride was estimated at £12 million. The park area containing Oblivion was redesigned as 'X Sector'. The only surviving ride from the former area was the Black Hole roller coaster, which was externally redesigned to suit the new theme. Alton Towers moved two existing rides from other areas of the park to open with X-Sector, Energizer and Enterprise. Both rides were repainted to fit to the new theme. Oblivion's vertical drop is actually slightly less than 90 degrees, at 87.5 degrees. This is due to the trains lacking sprung wheel assemblies which would mean the transition from vertical to horizontal would be uncomfortable. For a brief period in April 2011, the ride was sponsored by Fanta. However, much of the Fanta branding was removed after only a few months "following numerous complaints about the obtrusive nature of the brand". On 8 May 2012, a reportedly suicidal 20-year-old man climbed over tall safety fencing and managed to access the underground ride area. He reportedly entered via the tunnel exit portal and walked underground, emerging on a ledge around the entrance portal. Neither he nor any guests on the ride were harmed. He was arrested for a public order offence and the ride returned to normal operation the following day.
Ride experience
The queue line spirals upwards around a mound and passes through abstract buildings at various levels. Through the buildings, an unnamed man stood in darkness briefs riders from overhead television screens. In the heavily stylised videos, the sinister figure explains at length the supposed physical and psychological effects of riding on Oblivion. Although adapted from scientific fact, his monologues are deliberately exaggerated with hyperbole and dry humour. The third queueline video features an alter-ego character arguing with his counterpart as to whether Oblivion is truly safe for riders. The queue then splits and crosses caged bridges into the station building. Here riders are batched into rows and board the ride cars. Technical graphics are displayed on overhead screens, which change to play a final monologue upon dispatch. The cars accommodate sixteen passengers in two rows of eight with a tiered seating arrangement. The roller coaster has a simple layout with a 180 ft drop at 87 degrees. The car slowly ascends 60 feet at a 45-degree angle to build tension, then levels out and travels a turn towards the drop. The turn uses a horizontal chain mechanism not used on any other B&M dive coaster. The car reaches the drop and pauses facing over the edge for a maximum of five seconds, while a vocal sound effect is played over speakers whispering, "Don't look down". The car is then released and free-falls into the tunnel. Upon exiting the other side, a high-banked turn takes rides around into the brake run. In 2004, the "Don't look down" vocal was removed due to new sound restrictions on the park. In 2015, following a major crash on The Smiler, the third queueline video with the two characters debating the ride's safety was removed.
