to work service and not used again until 1953, when 2 of the regular motor cars (2006 and 2330) were damaged in an accident near Broad St. Thus, these 2 cars were returned to passenger service to replace the 2 that had been damaged. As a consequence, there have never at any time been more than 948 in service and 952 were actually built, but the number 950 serves as a convenient benchmark. 2 A cars (2714 and 2741) were used to replace those that had been in work service and were returned to passenger service. Regarding the 300 Pressed Steel motors, as they were first being delivered, the decision was made not to unitize the first 150, or half of them, to allow for the operation of more varied train lengths, notably for maximum 8 car length. The final 150 were unitized as B-types in much the manner of the earlier sets. In 1959, the first 3 2800 series units were tested for few months with the center car as a trailer, much like a BX unit. After the test was concluded, the motors were returned to these units, and they resumed operation as normal B-types. In later years, as the 2400 series was undergoing rebuilding, it was decided not to include the trailer cars in the rebuilding. The first 70 2400s had a 2600 series A-type car inserted in the unit (a total of 35 of these cars were used for this purpose); these units were designated as B-types. The remaining 30 2400s just remained as two car BT units, with as before, no provision for door operation in these cars. One first that occurred with these newly constituted units was, except for the first units put out, the remainder were equipped with link bar connections rather than couplers, making for a more permanent coupling that could only be broken up with great difficulty in the shops. All new cars subsequently purchased for the system made use of this feature and couplers were no longer used to join component cars in units. It should be pointed out that for several years prior to these rebuilt cars appearing in service in March 1959, many of the features introduced were already being tested out on a few cars. The rebuilt cars had their lighting system rewired for brighter lighting, similar to the IND R1-9s and the IRT World's Fair Steinways,