As RMT station workers struck over jobs and safety on Monday 9 January, tube drivers on the Northern line took wildcat strike action in support of a suspended colleague.
This is Hertfordshire reported that there were severe delays on the Northern Line throughout Monday, but they had little to do with that day's Tube strike called by the RMT union in protest at safety concerns over the new roster to be introduced next month.
The Northern Line problems were the result of separate unofficial industrial action by train drivers of the Aslef union, who walked out in response to the firing of a co-worker, accused of falling asleep at the wheel.
During the day, many stations on the network, including Southgate on the Piccadilly Line, were closed due to a lack of station staff. This line was running at only 50 per cent.
The RMT's 24-hour strike was the union's second in eight days, following action on New Year's Eve. All operations were running as normal on Tuesday.
Tim O'Toole, managing director for London Underground thanked the majority of London Underground staff for the dedication they have shown in maintaining services'.
He added that 90 per cent of station staff have signed up to the new rosters, which have also been validated for safety', but said he remained hopeful that the RMT would be willing to negotiate and iron out' any remaining issues, so that the new 35-hour week could begin as planned on February 5.
The RMT union has said the new roster has led to "back-door staff cuts" and could jeopardise Tube safety.
:> Account of the January 9 strikes
:> Interview about the reasons behind the strikes