4 52 Nanjing Puzhen Rolling Stock Works Type A 6-car sets (401-452) Line 5 22 Zhuzhou Electric Locomotive Works Type A 6-car sets, traction units by Siemens (501–522) 8 Zhuzhou Electric Locomotive Works Type A 6-car sets, traction units by CSR Times Electric (523–530) 21 Changchun Railway Vehicles Type A 6-car sets, traction units by Bombardier Transportation (531–551). 6 Zhuzhou Electric Locomotive Works Type A 6-car sets, traction units by CRRC Times Electric (552–557) Line 6 51 Nanjing Puzhen Rolling Stock Works Type A 6-car sets (601–651) Line 6 Branch 9 Nanjing Puzhen Rolling Stock Works Type B 6-car sets (6Z01–6Z09) Line 7 41 Changchun Railway Vehicles Type A 6-car sets, traction units by Bombardier Transportation (701–741) Line 8 24 Zhuzhou Electric Locomotive Works Type A 6-car sets, traction units by CRRC Times Electric (258–281[801–824]) Line 9 29 Changchun Railway Vehicles Type A 6-car sets, traction units by CRRC Times Electric (901–929). 22 Changchun Railway Vehicles Type A 6-car sets, traction units by INVT (930–951). Line 10 35 Changchun Railway Vehicles Type A 8-car sets (1001–1035) Line 11 33 Zhuzhou Electric Locomotive Works Type A 8-car sets (1101–1133) Line 12 56 Nanjing Puzhen Rolling Stock Works Type A 6-car sets (1201–1256) Line 14 44 Changchun Railway Vehicles Type A 8-car sets (1401–1444) Line 16 32 Zhuzhou Electric Locomotive Works Type A 6-car sets (1601–1632) Line 20 9 Changchun Railway Vehicles Type A 8-car sets (2001–2009) Signalling system On Line 1 and Line 4, Siemens supplied 7 (Phase 1) and 6 (Phase 2) LZB 700 M continuous automatic control systems; 7 (Phase 1) and 6 (Phase 2) electronic Sicas ESTT interlockings; the Vicos OC 501 operations control system with 2 operations control centers, fall-back level with Vicos OC 101 and RTU (FEP), 230 (Phase 1) and 240 (Phase 2) FTG S track vacancy detection units. Line 2 and Line 5 use Casco CBTC system with 2.4 GHz frequencies, and so the system has suffered frequent problems with interference from consumer Wi-Fi equipment. By the end of November 2012, CASCO solved the problem on Lines 2 and 5 by switching to their standard solution with frequency diversity on 2 different channels. Accidents and incidents 4 April 2011 – One worker was killed and four others injured on April 4 when a manually controlled chain hoist broke loose in a Line 5 tunnel in Longgang district. A preliminary investigation by district safety authorities