It means that if all station staff walk out, by law, the underground stations have to shut due to the sub-surface fire regulations (staffing) unless you can provide the legal minimum number of staff during all hours of operation.
MINIMUM STAFFING LEVELS:
Moorfields, with OHS open needs 5 per shift, 3 if OHS is closed.
Liverpool Central needs 3 (but try running it with minimum staff!)
James Street needs 3, possibly 4 with Water St open
Lime St LL needs 2
Hamilton Sq needs 3
That is 17 staff per shift. 3 shifts.
I suspect Merseyrail will try and get managers to cover the posts, but assuming normal shift patterns you'd need upwards of 50 for just one day, and I can't see it personally, so some of the Underground stations will probably close. Most, or all, of the outer stations will be shut.
Now, if the strike was to hit Christmas Saturday's, New Year, Aintree/Chester races etc I'd say that would be highly disruptive and make travelling on strike days very very difficult.
The staff involved are:
Clerical/Support (admin) staff from Head Office (Rail House)
Station Supervisors
Station Assistants
Station Retailers
Various grades of cleaners
Ticket Inspectors (RPIs)
I think the sticking point with this one is the SMART Pension, and the fact it's a 2-year deal with the second year being RPI+0 when analysts predict it could be negative, with no minimum payment to protect the lower paid workers..
Please don't turn this into a pay rise/t+c's debate!!!
Being balloted for action short of a strike, (probably means an o/t ban), or full strike.