03/17/14, 10/09/15- This cute pair of WWII-era diesel shunters are equipped with ESU LokPilot motor decoders. Since each has a motor drive, it took two decoders set to the same address, but programmed to drive in reverse of each other. IIRC, the decoders were an easy plug-in install, with bluish-white LED headlights changing when the direction changes. They're joined by a rigid plastic (removeable) rod.

I wish I could say that this 2-motor configuration made the doppellok a strong hauler but the reality is quite different. They don't have traction wheels, probably because they don't have any wheels to spare for this. Due to their short wheelbase and the fact that the motors aren't connected and don't share track power pickup points, the motors are vulnerable to loss of power. It happens when going over turnouts, bad spots of track, and the locomotives twisting within the track which makes the pickup wheels lose contact with the track. The result is that one of the two is momentarily pulling dead weight, a locomotive with traction wheels that aren't turning.

Driving them fast over turnouts minimizes this problem, but since they're switching locomotives, that sort of defeats their purpose.

I think this could be improved by joining the two motors electrically, but I didn't consider it worth the effort. In my Reichland layout, I assigned them to a short straight section of track in the yards that wasn't connected to the main line.

The motors seem a little loud but that may be because there are two of them and they don't have a sound decoder to drown them out.

They sure are cute though!

(10/28/15- After taking them out of storage and testing them, I admitted to myself that they weren't really good for anything, other than looking cute. With nothing to lose, I made some modifications: The decoder and motor were removed from one locomotive, and the power pickups were connected between the two. The idea was that the power pickup could be improved, and that one powered locomotive could haul the other one without the motor. The power pickup was improved, but the traction wasn't. These are such light locomotives that the unpowered locomotive wasn't heavy enough to make its wheels turn when hauled behind the powered locomotive!)