Dave...

I can only answer the last question. The retainer valve was located next to the brake wheel. Attached is a photo of a YVRR box car showing the retainer to the left of the brake wheel shaft.

I have a file with some information on retainers which includes the following:

“Retainers were stop-cocks in the brake cylinder piping (exhausting to the atmosphere). By closing the retainer valves (on a few of the cars), it closed off the escape path of the brake cylinder air on those cars. Thus, the brakes stayed applied to the wheels of the cars where the retainer valves were closed.

In order to release the brakes from the wheels, engineer moves the brake handle to recharge the train line pressure—- the restored pressure in the train line moves the control valve to permit air flow to recharge the auxiliary reservoirs on each car.”

So, setting some of the retainers keeps the brakes on those cars applied. The brakes are not completely applied on those cars, more like “riding the brakes” in a car on a downhill grade. When the train comes to a steeper section of track, the engineer applies the brakes and all of the car brakes slow the train down. When the brakes are released when the train gets to less-steep grade, the air pressure will start increasing in the system but those cars with the retainers set will continue to hold the train in check. The engineer needs the brake line pressure to move back up to normal to be able to apply the brakes on the next steep grade.

Attached is a photo of a YVRR box car showing the retainer to the left of the brake wheel shaft. Also attached is a retainer for YVRR stock car 701 (and grab irons) that I was able to save (with permission) before it was scrapped. They are on the street side of our porch railing.

Jack Burgess

www.yosemitevalleyrr.com