The Brass versus Nickel Silver et al Controversy

[USCentralSystem]

I just read through the posts and replies about brass versus nickel silver (N-S) track and want to share something I learned at a presentation by the Metro North Rail Road during a stopover at the destination of a fan trip which was to their Harmon Shop (once operated by the New York Central). They spoke about the composition of catenary which has a conductor wire and the "wire" that the pantographs slide along. The pantograph wire has to be hard to withstand the abrasion of the trains' contacts. However, to accomplish the necessary hardness requires a material that is not sufficiently conductive to carry enough power over long distances. Hence, a second, highly-conductive wire parallel to the pantograph contact wire is used to maintain power over the necessary distances between power stations. The brass vs. N-S track debate reminded me of my own experience with brass in a damp basement in my parents' home on Long Island, NY. It corroded and got very dirty fast requiring cleaning almost every time I wanted to run the trains. When I started my brand new railroad in my own home I opted for nickel silver track believing it to be impervious to the corrosion that plagued my brass rights of way. That was around 1977. Since then, the modular framework was moved once to another home in upstate New York and, then, to Connecticut where I expanded the original 8 x 8 to 8 x 16 and, finally, built a perimeter around the modular tablework for a much more extensive system. In the mainline track extensions, also in Nickel Silver, I was experi-encing a slow down along about five feet of track which I attempted to correct by adding additional power contacts at strategic points along the slow section. I thought it might just be that the prefabricated switches at both ends might have caused the loss of power or additional rail joiners. But, I did not think it might just be the lower conductivity of N-S to handle the length I wanted to power with only a single connection at a single point near one end. As it turned out, however, additional connections from a "parallel" electrical line below the table solved the problem. I have solved two such problems by adding copper wire connections to stretches of N-S track that had slowdown sections. The message I want to share is that only tonight did I find out that the conductivity of the N-S material itself is inferior to copper or brass; and, that powering an electric train requires solving the same problem faced by the prototypes in building effective catenaries. I had taken it for granted that N-S was superior to brass; and, I still feel that way particularly regarding corrosion. The basement of my home in Connecticut is relatively dry and free of dust and grit that fell on my first railroad on Long Island. So, except for the possible connectivity problem for long stretches of N-S trackage, all of its other features still weigh in its favor over brass. It was gratifying to solve a model problem using a prototype solution.

[USCentralSystem]

From the author of this post. The first word of the second from last line should be "conductivity" instead of "connectivity." I also apologize for making this post a single very long paragraph. I was delighted to have a place to share this with others and look forward to continuing to share with the community. Thank you all.

[tomikawaTT]

An excellent analysis.  In my own modeling I have found that NS code 83 rail has about the same conductivity as #22 solid copper wire.  My choice is to keep the rail sections short and to power each with a single feeder, preferably soldered somewhere near center.  The longest is 18 feet, and the feeder also acts as a jumper across the third rail joiner, soldered to the outside of both rails.

My variant of the MZL control system uses common rail, but that rail is also gapped at short intervals, and each section has a single feeder.  With individual feeders, each section of both control and common rails can be fitted .with an occupancy detector when signaling is desired - in my case, including five-lamp five-indication color lights with heads half a train length apart.

Here in the Dessicated Desert corrosion, even of half century old brass rail, just doesn't happen.  I have a dozen yards of brass, laid at the bumper ends of several back-in staging tracks, that is still clean and conductive enough to keep the markers lit when I park brake vans on them.  That area is cleaned, occasionally, with a Shop-Vac.  (The rest of my old brass rail is scenic material, pretending to be the new CWR scheduled to move onto the concrete ties the first weekend of October, 1964.  My signature explains why that makes the rail permanent scenery.)

Chuck (Modeling Central Japan in September, 1964 - TTTO, 24/30)

[USCentralSystem]

Thank, Chuck. You make a good point about placing the connection to each independent rail section close to the center. I am using Code 100 N-S which continues my suspicion that I had some weak points along the one block that had the problem I described. My placement of connections tended to be at the most opportune location since I was using Atlas Flex Track on plastic ties and tried to avoid soldering. Instead I relied on spiking a bare copper wire to the rail where this could be done least obtrusively. The remaining 64 square feet of my original movable pike was done with Atlas N-S Flex Track on fiber ties which I felt comfortable soldering wherever I felt the connection should be. In fact, I even soldered over some rail joiners to make the best possible connection. In N-S, however, I believe that all connections that involve simple contact with the rail will by very effective.