The work at the large complex, run by Border Holdings at Avonmouth, near Bristol, was masterminded by John Davies of J & E Hall, who continued his long association with the cold store where he began his career as a 16-year-old apprentice in 1980, at the then Union Cold Storage premises.

In 1969, J & E Hall installed the two-stage plant at the newly-built 39,650 cubic metre complex. J & E Hall recently won the refrigeration maintenance contract and carried out extensive repairs and upgrade work to the old ammonia system.

The old ammonia refrigeration equipment was replaced with state-of-the-art refrigeration plant requiring minimum maintenance. A key consideration was to install the new equipment in a -22°C cold store – with a seamless phase-out of the ammonia system.

Two semi-hermetic, economised screw compressor packages operating on R407F were chosen to replace the old system. Mr Davies said: “Once the cooler and compressor packs were commissioned, the ammonia plant was switched off and the new equipment maintained the temperature and ran trouble free.”

It was a proud moment for Mr Davies, who served a three-year apprenticeship within the Union Cold Storage Group. He joined J & E Hall in 1990, and until recently managed its Avonmouth Service Centre in Bristol, before becoming a J & E Hall technical applications manager.

Mr Davies added: 'I never thought that I would be the person to design and install a new refrigeration system to replace the J & E Hall ammonia plant which had served the cold store so well for so long.

'I think I have exceeded my challenge that I set myself at 16, that one day I would know how every component works – and I would be able to run and maintain this plant on my own.'

Border Holdings cold store commercial manager, Peter Brown, said: “We are already seeing substantial savings in servicing costs, because maintenance of the old plant was a costly exercise.”