Chemical Cleaning of Boilers and Feed Systems. June 1967. AUTHOR UNKNOWN. The following article is an edited version of a report on the Chemical Cleaning of Boilers and Feed Systems carried out in H.M.S. Berwick. The report was originated by Lieutenant I. Brannan, B.A. Grad.I.Mech.E. who was loaned to H.M.S. Berwick while the work was in progress.