Just for others to read here....
When you test motors with lower voltage DC, the amp draws maybe higher. That's one reason I run my outdoor G scale where the engines get 21 volts at the boards. The transformers are set to around 26 volts and there is power loss for all kinds of reasons.
When I first looked at USA Trains engines, the amp draws made it seem impossible to run on available decoders. The fact is that those engine like much higher track voltage which reduces the amp draws. I run my USA Trains engine with DCS decoders that handle them perfectly.
All this is just my opinion, and I'm sure others will post as well. Just don't test a 12, 18 or 24 volt motor with a weak 12 volt (HO) supply and wonder why the amp draw is so high!!!! You give the decoder what voltage it can handle and that decoder will handle the motors. Most every motor I've tested draws much less when in command mode. The output to the motor is pulsed to prevent damage I believe?
So I'd have to ask Peter, what exact power supply he tested with? I would state that a modern O scale decoder should handle a single motor Atlas switcher without any issue! I'd recommend at least using the 4 amp NCE decoder that I've used in dual motor USA Trains G scale. It has been out for many years. Right now, there's many choices available from others. If you are trying to run on HO power using HO decoders, you maybe walking a very thin line. Make sure you have the voltage up higher as the decoder will allow.
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I started O scale 2 rail with an Atlas SW 1 with a single horizontal motor about 10 years ago. It ran like a fine watch but drew about 5 amps making it a problem for DCC which I wanted to get into. I sold it and bought an old Custom Brass RS1 as I liked RS1's. This one had an old gigantic open frame motor that drew about 7 amps! So started my hobby within a hobby of remotoring and drive line work to get crawling speed and less that 1 amp draw so I could use HO decoders. It’s been a fun but time consuming journey.
BTW your layout is a wonderful thing to look at.
Peter
