Defence company BAE Systems has been fined £250,000 after a welder died while working on a North Sea platform.
Billy Farrell, 35, of Belton, Norfolk, fell to his death as he carried out maintenance work on a crane.
Norwich Crown Court heard on Friday that despite it being 90ft above the North Sea, there were no safety rails or toe boards.
BAE Systems Operations Ltd admitted failing to ensure the safety of a person other than an employee.
The Hon Mr Justice Cresswell said that the scaffolding used for the work was "unsafe and unsuitable".
He continued that although the work was subcontracted to Ark Offshore International, based in Great Yarmouth, health and safety on the tower "remained the ultimate responsibility of BAE".
Mr Cresswell expressed profound sympathy to Mrs Farrell and commended the bravery of friend Stuart Devine who had plunged into the sea to try and get Mr Farrell to a life raft.
BAE said that until the accident it had an impressive safety record and had reviewed its procedures since.