[ Read Responses | Post a New Response | Return to the Index ] Posted by MJF on Mon Jun 23 19:17:19 2003, in response to Re: Flushing Line to B Division?, Regarding why the older equipment takes longer to stop. The R33-36, along with the R32, 40, & 42 were retrofitted with composition brake shoes. In addition, the R33-36, which still has its original brake package, had the air inshot valve (which put the brake shoes up against the wheels as soon as the motorman applied a brake) removed. The emphasis is now on dynamic braking. Friction braking now comes in to play at the end of the braking process. Before the R33-36 through R42 were retrofitted, the motorman could enter the station and keep power applied for about 4 or 5 car lengths before he would apply the brakes, getting a harder, faster stop. Today the motorman generally shuts the master controller off as he gets to the entering end of the station and applies a brake at that point, to get the dynamic brake retardation, and continues to smooth out a stop as the friction brake comes in. This is a more time consuming process. The greater reliance on dynamic braking saves wear and tear on the brake shoes but has changed the braking dynamics, no pun intended. Responses
Replying to posts on SubTalk are disabled at this time. |