It looks like there has been a win for signal maintenance staff, who are no longer under threat of imposed weekend working.
This has been achieved by one thing: solid industrial action. Rather than roll over and accept the imposition of new rosters that would mess up their lives, signals workers demanded that RMT ballot them, then called not just a token one- or two-day strike, but over a dozen days of action, and 'action short of strikes' too. Because of this, management knew that they were serious.
This message was underlined when on the first strike day, there was 100% support - no scabbing - and workers from other grades refused to cross the well-organised and lively picket lines. This cost the company dearly as it had to cancel weekend engineering work and could not restore the services on several lines when signal failures went unrepaired.
Management have now withdrawn their threat to immediately impose the rosters, and will enter talks with the union to agree a process by which roster changes must be negotiated in future. They have also explicitly recognised that many staff currently work Monday-to-Friday.
However, the wording of the agreement also suggests that management may come back in a new attempt to bring in anti-social rosters a few months down the line. It is important that while celebrating our victory, we do not rest on our laurels; instead, we need to use this breathing space to build union strength and prepare for future attacks. In particular, there was a disappointing lack of action from London Underground operational staff refusing to work in unsafe conditions during the strike. Hearty congrats to those who did refuse, but in some locations, workers had neither the information nor the lead from local reps. Next time, we need safety briefings out in good time, and reps on site, and on the picket line, making it clear to workers in that location that if they take a stand, they will get full support.