Additionally, the cars are connected between each car with a minimum of a three conductor, or three individual cables. As soon as you disconnect a connecting cable, all the other cars behind it will be deenergized. Also, disconnecting a live 480Vac 3 phase cable from a socket will draw about a very bright and intense arc. Why install two disconnect throws or switches on every car (one on each end of the car) when at least one such throw or switch is located on the HEP generator or inverter in the locomotive already. Easier to disconnect the HEP from the entire train with one tag than hanging potentially 16 tags all along the train.
Here's a youtube slow-mo video of a 480Vac arc at a protected switchboard, note not at a plug.
https://www.youtube.com/watch?v=PO6see7_ODY
In the video was an electrician wearing all the protected gear required by OSHA; hard hat, flame resistant clothing, safety glasses and safety shield, rubber gloves with leather gauntlets, safety shoes, and all metal removed from his/her pockets. The dummy electrician in that video would probably survive such a failure because of the safety gear.
When was the last time you saw a train conductor wearing that much PPE?
Here's a youtube slow-mo video of a 480Vac arc at a protected switchboard, note not at a plug.
https://www.youtube.com/watch?v=PO6see7_ODY
In the video was an electrician wearing all the protected gear required by OSHA; hard hat, flame resistant clothing, safety glasses and safety shield, rubber gloves with leather gauntlets, safety shoes, and all metal removed from his/her pockets. The dummy electrician in that video would probably survive such a failure because of the safety gear.
When was the last time you saw a train conductor wearing that much PPE?