Plumber accepts faults on pipe involved in blast

EXPLOSION: Fitter says his work on boiler passed all other safety tests

A plumber who installed a new boiler at a house later completely destroyed in an early morning explosion told a court he “had to accept” a joint on a gas pipe he fitted had not been properly soldered.

Craig Hall said he double checked the system at Marion and Robin Cunningham’s home in Callander, Perthshire, was “gas tight” before firing up the new central heating equipment for the first time, but restricted space behind the fitting plate of the boiler made it difficult to visually inspect his work.

Hall, promoted to plumbing manager at Stirling-based TRS Plumbing and Heating Services in the years since the 2013 blast, said: “It passed on two different tests, everything was fine, no problems at all. There was no smell of gas, no leaks, the boiler was working and the customer was happy.”

Hall, 35, of Tullibody, Clackmannanshire, denies causing the blast by carrying out the installation of the boiler dangerously and otherwise than in accordance with appropriate standards.

He told Stirling Sheriff Court he could remember soldering all the joints on the boiler, which he put in August 2 2012.

However, he said he had to accept expert evidence that the solder had not in fact “run” in a so-called “Yorkshire fitting”, joining a vertical gas supply pipe to the boiler itself, which was found after the explosion to have separated completely, allowing gas at full domestic pressure to flood from its open end.

Hall told his lawyer, advocate Susan Duff, that because his work had passed gas tightness tests using both a traditional manometer and an electronic pressure gauge he “didn’t appreciate” that the joint hadn’t been made.

Cross-examined by prosecutor Shona Mcjannett, he agreed the British Standards Institution technical standard advice for soldering a Yorkshire fitting stated “the finished joint shall be visibly examined to confirm that solder has run”. He said he accepted that on all the other pipes he had attached to the new boiler, a “ring” of solder was visible.

However, referring to the gas pipe joint, he said: “It’s in a tight space, you’ve got a boiler in front of you, a jig plate in front of you and that’s why testing methods are in place as well.”

Mrs Mcjannett challenged: “I don’t think you soldered that joint at all, did you, Mr Hall?” Hall replied: “There was heat applied to every joint.”

The court had earlier heard scientific evidence that not only had the solder not run on one aspect of the fitting, but neither had the flux paste, which is used to assist the process.

Sheriff William Gilchrist asked Hall: “How do you account for the fact that the solder and the flux didn’t run?

“If heat had been applied it cannot have been very much or for long if it didn’t even melt all the flux.”

Hall replied: “At the time I thought everything was fine.”

Defence expert Professor James Lygate, 59, a forensic scientist and explosions investigator, said that “on the balance of probabilities” the gas that caused the explosion came from the separated pipe, but he could not say so beyond all reasonable doubt.

The trial continues and is due to finish today.

Picture: Central Scotland News Agency. Officials recover the boiler from the remains of Robin and Marion Cunningham’s home in Callander, Perthshire, which was demolished by a gas explosion in March 2013.