as mentioned in an earlier post the other three units should really be overhauled quickly and bought back into passenger service until they get the full refurbishment, fitting dellners to them quickly (for rescue purposes and in multiple with themselves) would obviously be needed. 170422 got fitted quickly enough.
Not good seeing stock sitting around for months while they are so desperately needed.
I have asked Southern this question in an email, the email asked about the works at East Croydon, the late running of the 18.05 ex LBG and as a bonus why not use the Class 170s as a 6 car unit on some diagrams.
The first two have been answered, well in a fashion, but customer services are waiting for a response from fleet on the bonus question. Suspect I'll be waiting a long time!