Inquest into Welwyn Garden City gas blast death begins
PUBLISHED: 16:04 06 December 2011
A SUPERVISOR working on a building site on the day a fatal explosion killed a father-of-two has admitted he had "no idea" of how dangerous the argonite canisters he was installing could be.
Shaun Jones, a senior engineer with fire protection firm Kidde, said staff had little formal training, saying “90 per cent” was done “on the job”.
Mr Jones was giving evidence on the first day of an inquest into the death of Adam Johnston, 38, from Sutton, Surrey, who was killed in the blast at Mundells, WGC, on November 5, 2008.
Hatfield Coroner’s Court heard today (Tuesday) how Mr Johnston was working as a plumber at a data centre being built for HSBC bank, when around 80 argonite canisters – used in fire suppression systems – discharged.
One flew into a corridor and hit Mr Johnston, killing him.
A jury was shown photos of the devastation, as well as footage of a “catastrophic” valve failure, showing an unsecured canister violently propelling itself across the floor.
Both Mr Jones and work colleague Leon Ruan told the court the canisters had not been fully installed by the time they left the site, shortly before the blast at 3pm, as the manifolds needed to fit them had not arrived.
Safety caps had been removed and the canisters had not been bolted, which Mr Jones said was standard practice at the time, adding the procedure had changed following the tragedy.
Asked why he didn’t replace the safety caps, he said: “My main concern was the cylinders falling and crushing someone.
“I had no idea the extent of how dangerous they could be when they propelled. If I’d known that I would have definitely put the safety caps back on.”
The inquest continues.