Article 7 Casual vacancies
If a Trustee refuses to accept office, or dies or resigns, or ceases to be qualified or becomes incapable of acting, or if the appointing body selects fewer applicants to become Trustees than there are vacancies, the resulting vacancy or vacancies may be filled in the following manner—
the Trustees may fill each vacancy by co-opting as a Trustee any person duly qualified in accordance with the provisions of this Order, and the Trustee so substituted shall continue in office for the period that the person in whose place the co-opted Trustee is appointed (or would have been appointed) would, in the ordinary course, have continued in office; and
at the end of such period the co-opted Trustee shall go out of office but shall be eligible for re-appointment if qualified.