| Andrew Michael David Kirkman | Director | 19 Jan 2016 | 30 Jun 2019 | British | 54 years |
| David Graham Brocksom | Director | 6 Dec 2012 | 31 Dec 2012 | British | 66 years |
| Geoffrey Keith Howard Mason | Director | 20 Sept 2012 | 12 Jul 2013 | British | 72 years |
| Geoffrey Keith Howard Mason | Director | 1 Sept 2014 | 8 Jul 2016 | British | 72 years |
| Ian Richard Ball | Director | 30 Jun 2019 | 8 Sept 2021 | British | 55 years |
| Jeremy Richard Hague | Director | 2 Jan 2013 | 30 Apr 2015 | British | 62 years |
| Michael Richardson | Director | 30 Apr 2015 | 29 Feb 2016 | British | 63 years |
| Theresa Marie Casey | Director | 1 Jul 2013 | 18 Jun 2014 | British | 58 years |