We can agree that C&S narrow gauge passenger equipment has two air hoses. Standard gauge equipment also has two hoses, but one of those is almost always a steam line for heat. The modernized "San Juan" had steam heat as well. But we know there was no steam heat in C&S narrow gauge cars.
The other possibility that I know of for the second hose is a second air hose for what I believe is a "Straight Air" system. I am by no means any kind of expert in this topic, but I have found and attached some information (from the trains.com discussion forum) which describes how a straight air system utilizing a second air hose works. So it may well be that this was the reason for that second hose. Interesting to think someone in the C&S Mechanical Dept thought this was a good enough idea to give it more than just consideration. If this is accurate, the main consideration was that the engineer was able to control retainer valve settings from the engine.
I have not been able to determine when the "Orinocco" (or Orinoco) system was developed, but it makes interesting reading, maybe especially for those of us who don't have any expertise in this area.
So, with sincere apologies in advance, if this is way off base, but check it out. It may help explain why the C&S applied a dual hose system to the B-3-C locomotives and passenger equipment. The following also makes reference to application of a second "independent valve" and cylinder.
Anything is possible, and we can't verify anything from existing equipment except possibly Coach #70, because the CB&Q seems to have reverted back to the Westinghouse system with all other surviving equipment in 1940 when it was used in the NY World's Fair.
This particular discussion relates to a straight air system used in the last 40 years or so on ore cars, and refers to it having been used on the Canadian National. As I have indicated previously, I believe the D&S has gone to a straight air system in the last several years. I don't know how it may compare to this. Anyway, here goes:
"The Orinocco or straight air, uses a second air hose (and second independent valve) which allows the engineer keep a constant pressure on every brake cylinder in the train, although he may be recharging the train line at the same time."
"Think of the Orinocco brake as a remote retainer set up system. The locomotive Engineer sets up the train brake with the Automatic brake valve. Then he can apply the Orinocco to hold the set he just made, following which he can make a release of the Automatic brakes while the Orinocco holds the application on the train. It does this via an additional set of brake cylinders attached to the car's brake rigging. Trains ran a feature on the DM&IR mini-quads and the Orinocco Brake in the '80s IIRC. At any rate they covered it along with a photograph showing the additional brake cylinder setup. After trying air dumping again on the first batch of new ore cars, CN has again gone back to the tried and true manual trapping to dump the ore cars."
"With the straight air, you can recharge the reservoirs on the automatic system, yet keep a set on the train, which can be adjusted. Makes coming down big hills with heavy trains a lot easier. You could turn retainer valves for a similar effect, but it takes a lot of time to walk the train, turn the retainer valves, come down the hill, walk the train again to return the retainer vales to normal, and continue. The ore trains were pretty much dedicated trains, so adding the Orinocco system was seen to increase safety and productivity."
The above discussion can be found at
http://cs.trains.com/trn/f/111/t/186414.aspx
Locked
