How does new director protect himself from old liabilities of the co.

If a company with 5 directors avails of a project term loan from a nationalized bank for a period of 5 yrs for a project, unfortunately they are unable to complete the project which has eventually lead to a shortfall of funds which in turn has put them into a bank liability that they have to pay within a stipulated period leading to the slowdown of completion of the project, in the meanwhile they want to incorporate an additional Director who will not only take charge of the project but will also financially aid the project. How does new director protect him from previous bank liability?