Julian Errington Ridsdale | 1964 | October 1964 |
Bruce Millan | October 1964 | April 1966 |
Merlyn Rees | 1966 | 1968 |
John Anthony Kershaw | June 1973 | January 1974 |
Brynmor Thomas John | March 1974 | April 1976 |
Alfred James Wellbeloved | April 1976 | May 1979 |
Geoffrey Edwin Pattie | May 1979 | 29 May 1981 |