Jim your points are correct. That is one reason I now pay for stainless steel rail clamps, less resistance at joints and I have never had a SS clamp break. Brass clamps have broken. I remove slip on joiners for outdoor track and install the clamps. Buying 8' long rail means fewer clamps and fewer joints to cause problems with conductivity or derailment.
Stainless Steel rail has permitted electric train operation with far fewer track cleanings, other than knocking off debri by pushing an LGB track cleaning block in a wheeled frame for one or two laps. I am impressed with SS rail. I admit I do not like the shiny rail look, although it does look like modern rail that is fairly new. Gary - chilling in Eugene, Oregon http://www.angelfire.com/or/trainguy http://community.webshots.com/user/raltzenthor Hi All. As Steve says "Conductivity isn't the only factor." The resistance between the power supply and the loco motor, consists of three components:- 1. The Conductivity of the rails. 2. The resistance of the rail joints. 3. The resistance of the loco wheels/pickups and the track. 1. Conductivity is not an issue because the rail resistance depends on the conductivity AND the rail length AND the inverse of the rail cross sectional area. The cross sectional area of our rails is quite large, so this reduces the effect of the resistance of the rails themselves nto pretty negligible compared with items 2 & 3 below. 2. This is probably the biggest source of resistance - conducting through two layers of oxide / crud between rail end and rail joiner, and then through two more layers of oxide / crud between rail joiner and next rail length and so on for every rail joint between the feed point and the loco - (and remember these are all in series in both rails -power out and return). It's a wonder the trains run at all. 3. The pickup resistance between wheels / pickups and track ( "Dirty Track" ) is the other contender for biggest source of voltage drop. Many rail materials do form layers of oxide or other grub on the rails, which are often poor conductors of electricity, and this one is probably the factor which most often should govern the choice of rail material. Note however that other factors can affect this - eg arcing (even microscopic) between wheel and track will do it, as will deposits from plastic rolling stock wheels. One often made observation is that a loco that runs on say 12 volts for the right speed in track power, often needs only 7 - 9 volts if powered by on board batteries - Three or four volts of what you are putting into the track is getting lost on the way to the loco - combination of rail joint loss and pickup loss.
