Such long service is unusual these days, but Mr O'Callaghan spent his entire career with Murphy, since joining as a graduate civil engineer in 1973.
Latterly he has been director of health, safety, quality and environment and sustainability, and earlier this year was awarded an Order of the British Empire (OBE) in recognition of his lifetime service to the construction industry. He is a trustee of the B&CE Benefit Schemes, a member of the Construction Joint Industry Council and director of the Civil Engineering Contractors Association.
Projects he has worked on include the Thames Water Ring Main, the Stansted Rail Link, the Channel Tunnel Rail Link and Crossrail Thames Tunnel C310.
He retired on his 65th birthday on Friday 27th November 2015.