16 ms·
Yeah, it's insane because it's 100% not true.
by alar44 4y ago
Yeah, it's insane because it's 100% not true.
- londons_explore 4y agoSurprising then that a company sells resistors just for rail speed control applications: https://www.cressall.com/applications/rail-traction-dynamic-braking/ https://www.cressall.com/applications/rail-traction-dynamic-... (scroll down to "MOTOR STARTING AND SPEED CONTROL RESISTORS")
- s0rce 4y agoThats not to "go slower" but to slow down: Whenever possible regenerative braking is used. In this case the drive motors convert the kinetic energy of the train into electricity, which is fed back into the power supply and used elsewhere on the network. If it cannot be absorbed by the system the energy may have to be dissipated with braking resistors. These braking resistors can be either mounted on the rail vehicle or as a fixed (trackside) installation connected to the third rail or overhead catenary via Automatic Assured Receptivity Unit (AARU) systems.
- fredoralive 4y agoThat section starts with "This was the traditional approach...". I guess the Bakerloo and Picadilly line trains from the 1970s might still use them on London Underground? Wikipedia mentions stuff like GTO thyristers and IGBTs on descriptions of stuff like the 1992 (Central line) and 1995 (Northern) stock trains, so the next oldest trains from the 1990s seem to have modern(ish) power control. And new trains are coming to the Picadilly line, and presumably must come to the Bakerloo at some point before the old ones fall apart.
- alar44 4y agoThat doesn't mean that's all that's used. It would also imply that it only has 2 speeds or something. Use your head. Or learn some basic electronics.