In the service diversions which you can see in its entirety by clicking here, you will notice that 1 train service between 137th & Dyckman Streets is suspended. The suspension is of course due to the brick facade collapse at the 181st Street station as well as work on a similar structure at the 168th Street station. Speaking of the stations, here is an update courtesy of a press release sent out yesterday by MTA NYC Transit:
Further repair work will be performed at 168th and 181st Street Stations along the 1 Line this weekend. The work requires suspension of train service between 137th Street and Dyckman Street from 12:01 a.m. Saturday, August 29th until 5 a.m., Monday, August 31st. During this period, it will be necessary, once again, for customers to either use A Line service, if possible, or a temporary bus shuttle between Dyckman Street and 137th Street.
While substantial inspection and corrective work has been accomplished at the two upper Manhattan stations, including the erection of a temporary shield at 181st Street, some additional stabilization work will be performed and temporary structures will be repositioned to maximize space along the platform.
Inspections performed last weekend revealed some areas of brickwork in the vaulted segment of the 168th Street Station that had to be stabilized. Additionally, NYC Transit maintenance workers stabilized areas of loose plaster, concrete and brick located in the extension part of the northbound platform.
Opened in 1906 and built as part of the Fort George Tunnel, both stations are of similar design and blasted out of bedrock 100 to 125 feet below St. Nicholas Avenue in Washington Heights. Known as the Washington Heights Mine Tunnel when built, this is part of the deepest section of subway in the City.