Do they need central door locking? I mean the slam doors being phased out didn't. Not even sure the final one to run on the south west trains network had central door locking.
I can see why from a safety point of view. Just thought they would leave it as it was, given they never bothered to update the other slam doors prior to retirement.
It would seem like overkill to me as well, but it seems to have been one of the sticking points so far.