Code 40 Questions and Answers
Q: Why code 40?
A: Model railroad track code is measured in thousandths of an inch, so code 40 would be .040" tall. Prototype 156 pound rail would be very close to .055" tall in N scale or code 55. 156 pound rail is the largest rail used in the US. It was used on a limited number of heavy main lines in the East and is very rare. Both Peco and Micro engineering make code 55 flex track. When Peco first came out with its code 55 track line I special ordered a bunch sight unseen because of Pecos reputation for smooth reliable turnouts. I was sure disappointed to find that the track used the same traditional toy like ties. It was hard to tell the Atlas code 80 from the Peco code 55 for this reason. I've since discovered the Micro Engineering track line with its 9" x 7" ties spaced 20" to 22" on center. This isn't toy track it's scale model track. Most main lines of today use 130 to 135 pound rail, which would calculate to be about .044" tall in N scale. Most older main lines used 100 to 115 pound rail along with secondary main lines of today. Many of today's sidings and heavy yard tracks use the same 100 to 115 pound rail. 115 pound rail would calculate to be about .040" in N scale, or the same as HO scales popular code 83 rail. 100 pound rail would be approximately .038 tall. 75 to 90 pound turn of the century main lines, along with spur and yard tracks of today, would be .028" tall. The closest commercially available rail size for most main lines, secondary tracks, sidings, and spurs is code 40. Micro Engineering makes code 40 Flex Track or code 40 rail and wooden ties. Trainworx makes PC solder ties, turnouts, and flex track laying tools.
Q: I've heard that you must have low profile wheels on all of your rolling stock to run on code 40 rail. Is this true?
A: This is false. If you hand lay your code 40 track using the Pliobond or soldering methods your full profile wheels will work fine. It is true that you will need to use low profile wheel sets if you intend to use Micro Engineering's code 40 Flex Track in order to keep the flanges from bouncing on the molded spike heads. Your locomotive wheels will also need to be low profile in order to keep contact with the rails. But don't loose sleep over needing low profile wheels. Most N scale freight and passenger car manufactures now deliver their product with low profile wheels as standard equipment. Micro Trains is one of the exceptions, but they offer low profile wheels separately and they are, in my opinion, some of the best in the business because of their perfect gauge and wobble free operation. Locomotive manufactures also see the need for lower flanges on their product. Life Like recently introduced their PAs' and PBs' with low profile wheels. Trainworx offers a flange lowering service for many popular locomotives, or new original equipment parts that have already been lowered. Better yet, purchase your locomotives from Trainworx and have them delivered to you with the flanges already lowered, ready to run on code 40 Flex Track
Q: Will low profile wheels cause more derailments?
A: If you're having derailments with full profile wheels then you can expect to have derailments with low profile wheels. A derailment can never be attributed to the wheels flange depth because the wheel's tread should never be able to loose contact with the rails. Here are the most common causes of derailments in order from most common to least common. (1). Rough track work or track joints. Follow Trainworx recommended track laying techniques for smooth reliable track work. (2). Track and wheel gauge. Both your track and wheels must be in gauge for trouble free operation with any rail code or any wheels. The NMRA standards gauge is a valuable tool in checking for proper track and wheel gauge. (3). Car weight. Proper weighting helps your rolling stock track better especially if you intend to run long trains. Refer to the NMRA recommended practice of .5 ounce of initial car weight plus .15 ounce of weight for each additional inch of length, for proper weighting. (4). Truck mounted couplers or talgo trucks are the cause of many derailments especially when backing trains. The longer the train the worse the problem becomes. Body mounting your couplers will eliminate many derailments that occur when backing trains. You will run into cars that seem to have no way to body mount a coupler. Remember to place these cars at the rear of the train to reduce derailments.
See how Trainworx recommends laying track for trouble free operation. These suggestions are only guidelines and are not the only way to lay track. You must choose the method that is best for you.
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