I was not aware that a 6N had issues with the lubricants used in steam compressors, but am glad that J. David pointed it out. I know that WM 734 has a 26-FNL system, with a 6N (and the 2A an 2B ports), but I think they also have one of the Salem air dryers, which may help seperate out some of the oil as well as water.

With a mountain railroad, it would be nice to have some sort of pressure maintaining capability. I wonder, and I'm asking, if a 26-NL system might work here. The literature I have for the 26-NL calls a 26 valve in the cab and a 6N distributing valve, without the 2A nd 2B ports. If a 6N can be used to replace a 6K or 6KR, it seems logical that a 6K or 6KR should be able to replace a 6N on a 26-NL system. Or did I miss something here?

Just as an aside, I know of a whole fleet of RS-11s that had 24-RL brakestands and 6N distributing valves (no 2A, 2B). I'm not sure what that system would even be called-

I believe the D&S found a way to help crews control downhill operation by running a second train line, which sent controlled air through the retainer lines into the cylinders......anybody with particulars might well chime in here. Such an addition rather than a whole system retrofit could make good use of existing hardware and help with lost skills.

Of course, well trained engineers who know how to brake safely and allow adequate recharging is best.

dave

Dave described the Orinocco system pretty well, which was also used on Erie Mining and the Missabe. Its basically a straight air system that maintains a brake cylinder pressure through the retainers while recharging, but will also allow an automatic emergency application in case of derailment or a parted train line. Best of both worlds, automatic and straight air-

So what would we use - something like a S1 brake valve for the retainer air? Maybe a feed valve to reduce the pressure to 40 or thereabouts? It's been a long time since I saw it.

dave

The D&S installed the straight air as an experiment to see if they could save wheel profiles on the passenger equipment, but it apparently didn't make any real difference. They still use K-1 and K-2 triples on all of the regular passenger service equipment with 6 ET schedule brake valves on the locomotives. I never worked with the distributing valves enough to tell you the difference or which ones they use now. The straight air is a separate line that runs the entire train length and is plumbed in to the retainer exhaust line. 99% of the trains run 99% of the time with the straight air handling the brakes, and it reacts much more slowly than an equivalent automatic brake set would make. It's a neat system, and I understand that possibly some unit trains in the past at other railroads used a similar set up for blocks of cars that didn't have much need to be cut apart very often.

Both 18 and 29 at GCRY were equipped with the 26-NL system. I am not certain, but I think we used 6N distributing valves on them. I don't recall having any problems with that arrangement.

We installed the 6-ET system on 401 and are using a 6N distributing valve. We also installed a filter in the supply to the brake system which helps keep all the brake equipment cleaner. So far, we have had no problems. However, the engine sees very limited service and in a more severe operating environment it might be a different story.

As far as function from a train handling standpoint, the 6-ET and 14-EL systems are the same. Having only one pipe bracket to mount holding both independent and automatic valves makes the 14-EL system a little more compact in the cab.

After handling trains for many years with the #6 air and retainers on the C&TS the 26 brake valve we used on the GCRY engines took a little getting used to. The pressure maintaining feature is nice. The trains were fully equipped and set up for graduated release so we were able to use the Passenger position with that as well.

The 26 brake is a self lapping valve and I feel that it is a little less accurate when making a brake pipe reduction. With experience, it is easy to make very precise reductions with the No. 6 brake valve. With the No. 26 valve, once you go beyond first service, it is a little bit of a guess where it will land. They are not as sensitive when you want to just add a pound or two to a reduction. It may take 3 or 4 pounds of additional reduction of the equalizing reservoir before the valve begins to exhaust. Usually, if you just need a small reduction all you can do is reduce the equalizing reservoir 1 or 2 pounds and then wait for the brake pipe leakage to make the actual reduction. This is not a really big problem, but does take some getting used to and a little patience at times.

Russ

This is slightly OT, but related- I saw a tank engine over the weekend that had train air, but only one brake valve and what looked like an OLD freight car triple valve on a reservior under the cab. What schedule was I looking at? My best guess is that the brake valve was an automatic, and that the triple made the engine brakes come on just like a freight car, with no independent control?

That would be A-1 equipment. You are correct in that the engine brakes are controlled by the triple valve. A straight air valve and double check valve could be added that controlled the engine brake directly. These straight air valves were ofter mounted on the side wall of the cab.

The 6-ET schedule equipment made several improvements over the A-1 system.

Thank you all for the great input--I knew there were a lot of Real Smart folks here!!!