Roz briefly reflected upon this in another article, but Roger Jones, a now-retired HSE engineer, explained how he was able to wriggle out of Intamin's T-bar restraint despite it being fully down on Oakwood's Hydro.
Hayley Williams was killed when she fell from the ride in April 2004. Image expert Andy Laws, who examined CCTV footage from the ride, explained that it was unlikely that her restraint was down when the ride was dispatched.
The T-bar restraints have since been removed from Hydro, and replaced with overhead restraints as per recommendations by the Health and Safety Executive (HSE).
Hydro's restraints were similar to ones on Perilous Plunge, where Lori Mason-Larez, a 21-stone rider, was ejected and killed in a similar accident. California's health and safety department, OSHA, described the restraints as 'clearly not adequete'.
Although Hydro's restraints were a later version of the Intamin T-bar, earlier versions were also jinxed. An ejection on a Superman mega coaster in America lead to the installation of seatbelts on all further installations, while a latter ejection killed a rider at Six Flags New England.
Interestingly, the inquest heard from Hannah Williams, 15, Hayley Williams' sister, who said that restraints were lowered once, but then were released and re-locked. Many riders on the boat were not rechecked - including Hayley Williams, Hannah Williams and Miles Mitchell who gave evidence yesterday.
Roger Jones tested all 24 seats and seatbelts. He commented that without the seatbelt it was easy to escape the restraints. Jones added that with the seatbelt, it was perfectly safe, but followed up by remarking that the seatbelt can be unfastening the seatbelt could go undetected.
Many of Mr Jones' findings, however, are a moot point - the hearing has also heard that while the assistant who was supposed to check Hayley Williams' restraint was in her vicinity for approximately 23 seconds, although didn't check her restraint. She gave evidence to the effect she was distracted, and upon turning back the boat had been dispatched.
Apparently people were in good spirits as the boat rounded the 180-degree turn into the drop. Craig Sutton Jones, who was sitting next to Hayley's sister in the second-from-back row commented people were singing - "quite a few people had their arms in the air" he continued.
Elizabeth Humphrey, 16, saw something yellow fall from the boat and assumed it was Hayley's distinctive yellow waterproof poncho. She then realised the seat was empty and began screaming.
The changes to the restraints on Hydro were made in 2005 following feedback from the Health and Safety Executive. Since the accident, only one ride - Galaxy Express 999 - has had Intamin's T-bar restraints fitted - rides like Rita - Queen of Speed and Stealth have overhead restraints, while a ride almost identical to Top Thrill Dragster, which has lapbars, has been fitted with overhead restraints.
Changes were also made to the restraints on Perilous Plunge following the accident on that ride to include over-the-shoulder seatbelts.
Changes were also made to the other two rides in California with similar restraints; Xcelerator, which now has a measuring device to ensure overweight riders cannot ride and extended side-support on the seats - and Superman at Magic Mountain, has had similar changes made.
Superman: Ride of Steel at Six Flags New England ejected a rider with cerebral palsy after operators failed to adequetly check his restraint in 2004. Changes were made to the restraints to include leg and ankle restraints, shorter seatbelts and measuring devices to ensure overweight riders cannot ride.
The accident on Superman happened just after Hydro's accident, and findings from that investigation were included in the investigation into the accident at Oakwood.
Changes were made to later versions of Intamin's retraints - including those made on Hydro - to reorientate the bar better to restrain the rider. Some rides also had raised floors so that riders' knees were over the height of the lapbar or blocks on the floor to lock the riders' feet in place.
Most of Intamin's rides with lap bar systems do not have sensors to detect whether restraints are lowered or not. As they have infinate positions (and don't ratchet like traditional lap bars), it is in theory possible that the restraint was not lowered and could have gone undetected if the assistant was distracted as the inquest today heard.
Source, in part: icWales
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