Hang, Dan Brown

Only EY was down from this dolphin crash so this recovery was quicker than some of the others.

Initial alignment went fine except for PRC align. It seems the PRC1 filter changes made the other day  (46151) made it unstable for initial alignment, probably too much gain. In PREP_PRC_ALIGN Guardian we switched off all the filters apart from FM1 (-20dB), it converged slowly and with FM1 off it still works.

Only one ALS lockloss during LOCKING_ALS, DRMI locked in about 20s.

Took about 2 hours until we were up again - although most of that was checking CO2Y table for leaks and figuring out what was up with PRX initial alignment rather than the Dolphin crash itself.