Ancillaries, such as electrical and air-conditioning systems, were grouped together in discrete modules housed behind an aerodynamic skirting between the bogies; on the Mark 2, these were mounted above and below the passenger seating area. The lighting and air-conditioning fittings were for the first time integrated into the ceiling panels. Other new features were the pneumatically operated automatic gangway doors triggered by pressure pads under the floor. From 1993, after fatal falls from moving trains, a central door-locking system operated by the train guard was installed to protect the passenger operated slam doors.