Burdened by an unmanageable debt load, The Westerly Hospital will ask a state judge to appoint a "special master" to take control of its finances. The hospital's board of trustees voted unanimously Monday night after a three-hour meeting to voluntarily file for receivership. Charles S. Kinney, hospital president and CEO, recommended the action. The hospital plans to make the filing on Wednesday. If receivership is approved, the court would appoint a special master who would assume fiduciary responsibility for the hospital. The master would work with the hospital to restructure its debt and address its financial problems.