"Token Block Signaling on the Orange Line"
On the chilly evening of January 14th, 2023, a MBTA Inspector is seen "passing the baton" to a train operator before removing a portable trip arm just behind the frame at Community College station on the Orange Line in Boston, Massachusetts. The baton/ token (a green flag) is the train operator's authority to enter the temporary, single-track manual block zone that was created between Community College station and North Station during a weekend shutdown caused by the Government Center garage demolition project.
The manual block token system is a practice that was first developed by the British in the 19th century to enable the safe movement of trains on single track portions of railways. The operator of any train entering the or occupying this portion of track must be in possession of the baton/token which prevents collision with another train.