Worldwide and Chinese Straddle Monorail Standards Comparison

As straddle monorail doesn’t have specific standard currently in place, IMA (International Monorail Association) refers to ASCE 21-13 APM (Automated People Mover) standards. In 2018, China start updating GB 50458 Code for Design of Straddle Monorail Transit to support UTO and DTO operation. Although both worldwide and Chinese standards support fully automated operation, there are many differences in the fields of system architecture, function requirements, interface design, etc. The biggest difference is that Chinese straddle monorail require independent CBI (computer based interlocking) and axle counter, which can support fallback interlocking level operation even degraded intermittent ATP/ATO mode. In addition, Chinese ATS should have central and local control workstations, but the worldwide ATS only requires central ATS. Once the redundant central ATS fails, the wayside ATO will take over automatically. Chinese ATP define more operation mode, except UTO/DTO, CM, EUM, which still have ATO, RM, and creep mode, and some modes transition need train non-stop, but worldwide ATP only have UTO, CM, EUM modes, and mode transition shall stop train firstly. Chinese ATO require more functions like overshoot and undershoot automatic run backward/forward, but worldwide ATO will go to next platform while overshoot happens; Chinese ATO have more working condition management like online/offline, cleaning, wash, maintenance, etc., but worldwide don’t have them. External interfaces also have more differences: Axle counter is installed along the whole line, and dummy wheel is installed onboard to assist wayside wheel sensor detection; Signal shall be same as metro operation with at least 3 aspects; Switch still have outdoor control cabinet, but control logic need more manual authorization in local mode; PSD is independent integrated system with control cabinet, signaling just connect to the cabinet for control purpose, but worldwide PSD control is part of signaling, which have each door set PLC connecting to signaling inside; train wash plant must support automatic train wash including entry/exit and wash schedule; onboard TCMS and ORS shall be separately. Worldwide and Chinese straddle monorail standards comparison could help both sides improve technical standards and system performance, make monorail better promotion even interoperability among different suppliers in the world.