Downtown trains were not making local stops Monday between 125 St and 59 St. – Columbus Circle — and major delays wracked the A, B, C and D lines — after scheduled weekend track work uncovered a crack in the tunnel beneath Central Park West.
The compromised concrete was discovered during planned track replacement in the tunnel at the 81st St./Museum of Natural History station. Since the tracks are meant to be partially embedded in the tunnel’s concrete floor, workers were unable to install new tracks into the damaged surface.
Uptown local service on the C train remained in effect Monday, but the B train was rerouted along the M and Q lines.
Severe delays were reported on the A, C and D lines as a result of the changes. New Yorkers needing service to and from the Upper West Side were advised to rely on the Nos. 1, 2 and 3 Broadway trains.
The MTA announced late Monday that traffic had been restored in time to avert any delays Tuesday morning.
A source with knowledge of the damage to the tunnel told the Daily News that work crews were attempting to temporarily anchor new track using crushed-stone ballast — a method typically employed elsewhere in the subway as well as on above-ground railways — before making more permanent structural repairs to the floor of the Central Park West tunnel at a later date.
The tunnel under Central Park West is a two-level tunnel, with downtown local and express service occupying the bottom level. It remained unclear on Monday whether the structural damage under the local tracks extended beneath the express tracks on the same level.