Re: Brake staff /cylinder confusion -- 1900 C&S stock car at museum.

Posted by John Greenly on Feb 18, 2017; 9:59pm
URL: http://c-sng-discussion-forum.254.s1.nabble.com/Brake-staff-cylinder-confusion-and-mismatched-trucks-tp3464p7728.html

Keith and Jim, thanks so much for this thread- I've been wondering about this too.  I'm very glad to see that part "Y" did not exist as in the Grandt diagram.  I didn't include a part like this on the 1902 coal car I'm building because I couldn't understand what it would do.   I was wondering, though, if it might be part of a bracket for a suspension of the central link. Your photos show this clearly, so that puzzle is solved, thanks!!  

As to the handbrake though, now I'm even more confused.  If indeed the cylinder rod cannot move unless the air is activated, then how can the handbrake work in the modern rig, when it is attached to the essentially fixed lever end that is enforced by the non-moving cylinder?  

As to the older rig, I think Konrad's suggestion makes perfect sense, with some sort of additional stop as Jim has suggested.  May I suggest that the stop could have been as simple as a second piece of chain,  attached to the end of the brake rod where the chain to the brake staff is attached, but leading to a fixed point, perhaps on the bolster or the frame end beam.  This second piece of chain would hold the rod tension when the air is applied, and just go slack when the handbrake chain is pulled.   In any case, I agree with Jim that whatever fulfilled this function was likely hidden in the bolster/truck area, so on a model could just be left out- at least until Jim finds that holy grail of photos!  If my suggestion were correct, then maybe an extra bolt head or two on the A end of the car end could betray the attachment point for a second piece of chain…?

Okay, now to confuse this further:  Konrad's/Jim's A end handbrake rod would only work properly if indeed the cylinder enforces a fixed point at the lever end it is attached to.  So this arrangement and the modern one to the B end seem mutually exclusive in light of my question above-  if the cylinder makes a fixed point, A end works and B end doesn't, while if the cylinder can move, B end works and A end doesn't.  No?

help!!?
John

John Greenly
Lansing, NY