Unusually the brand new grinder 79266/76 has arrived at Tube Lines Lillie Bridge depot. Normally they use the smaller Schweerbau units but perhaps they have fallen out of favour after the incident last year!
Harsco grinder to Lillie Bridge - On-Track Machines - Forum
Harsco grinder to Lillie Bridge
...of course this is almost certainly unable to work the underground sections of line.