31-01-2024, 06:21 PM
(This post was last modified: 31-01-2024, 06:22 PM by ppppenguin.)
A lot of modern trains, and possibly trams too, have AC traction motors and variable frequency drives. The AC motors are more efficient, more reliable and need less routine maintenance. If you want regen braking the VFD has to be bidirectional too.
Some tube stations are raised but it's far from universal. The headway on lines that have modern signalling is sometimes only a minute or so. One train leaves the platform and the next one arrives within seconds. Running that frequency of service needs good acceleration too. I've lived near the Northern Line for much of my life. At one time it was often called the misery line but now it's pretty impressive most of the time. Unlike the Central Line which has huge problems with availability of trains. On the Northern and other lines you can hear the whine of VFDs. Not like the comforting click-click-click of old fashioned motor controls.
Some tube stations are raised but it's far from universal. The headway on lines that have modern signalling is sometimes only a minute or so. One train leaves the platform and the next one arrives within seconds. Running that frequency of service needs good acceleration too. I've lived near the Northern Line for much of my life. At one time it was often called the misery line but now it's pretty impressive most of the time. Unlike the Central Line which has huge problems with availability of trains. On the Northern and other lines you can hear the whine of VFDs. Not like the comforting click-click-click of old fashioned motor controls.
www.borinsky.co.uk Jeffrey Borinsky www.becg.tv
