Charitable trust - can son be a trustee after father's death

In a Public Charitable Trust (family owned) one of the Trustee has died some 14 yrs ago.

My questions ;

1)  Can his son become the trustee now, if so what is the procedure and how early can he become

2)  If there are 5 trustees, during a major decision of Trusts do all the Trustees have to agree or does majority prevail.  And what if 3 trustees have made a nexus. how to solve it

awin