Electric brakes

[John Ashworth]

I've just been reading comments online about the recent Chicago train crash (see http://www.friendsoftherail.com/phpBB2/ ... 43&t=11648) and it seems that the Chicago metro sets have no air or vacuum brakes, only electric braking. "Fully dynamic down to single digit speeds, then an electrically-actuated disc brake to bring the train to a full stop." They "also have track brakes which are a long strip of flat brake pads that hang about a centimeter above the rail between the wheels under each side of a truck. They are meant to hold cars sitting in place and I think they can also be used as an emergency brake." (See http://www.railroad.net/forums/viewtopi ... 1&t=152821)

Does anyone know more about all-electric braking?