RMT secretary Bob Crow said: "Our members have the legal right to refuse to undertake duties that would put themselves or the travelling public in danger."
The RMT established this as a right within LUL following our refusal to work on safety grounds during the FBU dispute; the company settled out of court (well, in the canteen at the Employment Tribunal to be exact) so there's no case law but at least we have established the right within LUL.
The business about "signalling problems" last week, to be fair, isn't so far from the truth because the Underground automatic train protection (ATP) on all lines other than the Central, is directly and mechanically linked to signals. If a train goes past a signal at danger a metal rod attached to the signal activates the train's emergency brake system. It is this ATP that's prevented the sort of accidents seen on the main line service which has no similar system.
As drivers we are taught that this is a "fail-safe" system, so to find out that it isn't can be quite a shock. The number of signals passed at danger (SPADs) on LUL is quite high, but accidents are avoided by the ATP. On the Northern Line the ATP has failed on numerous occasions; we are demanding double crewing not because we're lonely but because if one driver collapses over the controls the second will avert a tragedy.
Both drivers' unions, ASLE&F and RMT (currently 50% membership each) have rightly taken a hard line over this in supporting their driver members. A gung-ho manager on the Northern Line sent home a number of drivers without pay which is what has prompted the strike ballot calls. It is unlikely it'll come to this as senior managers are a bit more clued up about the law and industrial relations in the run-up to 2012.
Essentially the Northern Line is currently unsafe; managers wanted to run it anyway; the drivers at the pointy ends refused; the unions backed up their members. The drivers on this occasion, as on many others, are showing a more responsible attitude to the safety of their passengers than are the managers.
The "internal market" that arose through the privatisation of the maintenance section is seriously undermining safety in every area across the whole of the combine. It's only a matter of time before poor maintenace results in a disaster on the Tube. Everyone acknowledges this privately, but all those senior managers now earning in excess of £100,000 pa are keeping schtum.