If you have your own car and want to come here, you have to park at Nagasaki Station and wait for its bus to pick you up and take you to the museum. Check the time table of the bus before planning your trip to here. I ended up not being able to make it here so the star I gave is for the arrangement of the company.
Great to visit the Mutsibushi Heavy Industries Museum, it is a fantastic centre for understanding the heritage of the company. As an Engineer the most interesting exhibit at the museum was a piece of a steam turbine rotor. The exhibit shows a 9 ton piece which is only a quater of the total rotor. Due to a manufacturing defect the rotor catastrophically failed and was thrown 800 meters away. The importance of the lessons learned from the investigation into the failure and the resulting changes to the casting process is what Engineering is all about. Great place to visit. Thanks for your hospitality.