The ideal treatment for hemothorax greater than 500 ml/hour -
Following are indications of thoracotomy in blunt chest trauma:

Initial drainage of blood > 1000 ml, especially if fresh.
Continued brisk bleeding > (100 ml/15 minutes) from the intercostal drain
Continued bleeding of > 200 ml/hr for > 3 hrs
Rupture of bronchus, aorta, esophagus or diaphragm
Cardiac tamponade (if needle aspiration unsuccessful).
Wait and watch
Needle aspiration
Intercostal tube
Open thoracotomy with ligation of vessels