Awakening of a 50 Years old CHM Network, Dead for last 6 Years

Sounds like a Hollywood flick, it was nothing less than that either, when I was called upon to inspect a CHW network constructed 50 years back and was out of service for last 6 years, chiller plant was 50m below from ground levels, access was hardly available to move around, completely dark as we have to use flash lights, I have witnessed 4nos water-cooled chillers each of around 1400KW/400RT  with circulation pumps which were in appalling condition as they have completed their life….