law: 112. Power to convene a summary general court-martial.-
  The following authorities shall have power to convene a summary general court-martial, namely,-
  (a) an officer empowered in this behalf by an order of the Central Government or of 1[the Chief of the Army Staff];
  (b) on active service, the officer commanding the forces in the field, or any officer empowered by him in this behalf;
  (c) an officer commanding any detached portion of the regular Army on active service when, in his opinion, it is not practicable, with due regard to discipline and the exigencies of the service, that an offence should be tried by a general court-martial.