Rail passengers suffered fresh delays because of another incident of cable theft today, a problem a union leader said was now "out of control".
Services run by c2c between Essex and London were hit because of the theft at Rainham, causing disruption during the busy morning rush hour.
Bob Crow, general secretary of the Rail Maritime and transport union, said: "The problem of cable theft on the railways is escalating out of control.
"If a chunk of the excessive profits of the train companies was invested in visible staffing, track patrols and security we could get a grip on this criminal disruption to rail services."
There has been a spate of signal cable thefts in recent months, causing huge disruption to train services across the country.
Signalling problems also caused disruption to National Express East Anglia services, leading to delays of up to 50 minutes between Ipswich and Cambridge and Ipswich and Peterborough and to First TransPennine Express and Northern Rail trains between Huddersfield and Stalybridge.