London Underground Ltd fell short of safety standards
Judge John Samuels QC accused the company of "sacrificing safety" in order to keep the trains running "at all costs".
Blackfriars Court in London was told at an earlier hearing that track workers were put at risk of electrocution and several had suffered electric shocks.
The judge said: "LUL, despite the lip service they paid to health and safety issues, fell lamentably short of the proper safety standards and, objectively, simply ignored their obligations in this respect.
'Safety disregarded'
"A pattern of protracted disregard for basic safety procedures by senior management for so long must be marked by a heavy penalty."
Track maintenance men had been ordered to work in the dark with the track current still switched on, often while it was raining.
One of the workers who suffered an electric shock ended up in a hospital wired up to a heart monitoring machine for three-and-a-half hours.
London Underground Ltd has admitted six health and safety breaches at a previous hearing.
The judge accepted the company was now addressing safety issues.
At the earlier hearing at the court, former Tube signals operations manager David Elkington was found guilty of four counts of "failing to discharge a duty" under the Health and Safety at Work Act between April 1998 and January 2000.
The 51-year-old from Lymington, Hampshire, was ordered to pay a total of £5,000 in fines and compensation.
The court had earlier heard Mr Elkington was nicknamed "Dangerous Dave" and had been described as a "bully".