The lower level platform of this station was originally built with the intent of allowing Broadway line express trains to continue south of city hall. The local tracks in the active station above were originally intended to be a terminal, were local trains would be turned and routed back north. This plan changed, however, when it was decided to send the express trains out over Manhattan Bridge.
Thus, this lower level abandoned platform never saw a single passenger train. Instead it became a convenient place to store trains during off peak hours. It was designed similar to the Whitehall street station – with a third track in the center of the station for turning trains in either direction.
South of the station, the tunnel dead ends as the ceiling slopes downward. This stretch of abandoned tunnel is filled with pools of water – and for a long time those pools of water were covered with dust from the destruction of the World Trade Center on 9/11.
One fine Christmas night, a group of us reprobates got together and invaded this abandoned platform. There’s a lot of fun to be had in throwing caution to the wind and running with a pack into the unknown. This was a relatively calculated risk, of course. We timed it to avoid all kinds of trains, or so we thought.
We found the doors to a layup train open, which made it far easier and significantly less dangerous to simply walk through the train than trying to squeeze through no-clearance walled tracks stacked with laid up trains.
Eventually we made our way back towards our exit point, only to run into what always comes in the subway tunnels: the unexpected. At strong risk of being caught, we made our escape into the bitterly cold night. Knowing it best to get off the streets, we made our way into a nearby hotel where we found a coffee/hot chocolate machine to pilfer and loot warm drinks from. We chilled out and left awhile later when we were sure the heat on the street had died down, splitting up, with everyone content that we had given ourselves the best holiday present money can’t buy.