2 motors in loco vs. 1

Just my opinion but, the "logic" behind 2 motors in a diesel model is,,,,,,there are 2 trucks and each truck needs its own motor.

Think of the motor as part of a drive system as the motor alone does not constitute how well a locomotive will pull a train.  The motor is an important component, however consider the size and type of flywheels, command control if any, the gearing ratios and ultimately the amount of weight holding the wheels on the track all factor into the tractive effort of our models. 

There are several examples of single motor models that outperform a similar double motored locomotive and the same is true the other way around.  It all depends on the model.     

Better traction and prototypical correctness. 

Sorry, but no cigar on prototypical correctness. 

The typical prototype 2 axle diesel locomotive truck has a motor on each axle.  A three axle diesel locomotive truck has 3 motors, or in the case of an E-unit, a motor on each of the outside axles but none on the middle axle.

Rusty

Rusty

Easier to squeeze in two smallish motors than one large one; makes more room for whiz bang electronics; eliminates having to engineer a complex drive train and possibile failure points to provide eight or twelve wheel drive to two trucks.

Pete

"prototypical correctness"???????    How do you figure that?

I think the 2 motor set up was implanted "mainly" due to real estate concern inside the loco shell to be able to house electronics and such. A side benefit is, of course extra, weight and traction. It is better to have two motors than have one big one with two drive shaft (front and rear) and lose the extra room and not be able to put all that electronic stuff. Also,universal shafts while very useful, create drag and slight loss of power (steam engines need U shafts more).

Look at articulated steam engines today. Most have One large flywheel, Again real estate is highly limited inside a steam loco and it makes more sense and good engineering practice to have a short shaft between the two articulated engines and have more room for smoke units, electronics, speakers and so on....Check out the inside of the VL BB.

Just a guess on my part.

I will point out that I have several steam engines (MTH) with 2 motors in each. The Articulated Railking engines have one motor per set of drivers.

Admittedly, these are all BIG engines. and they are thus heavy as well, The traction in them is untested by me but they each can pull more than I can get on my layout.

There is a Video of my Oldest Big Boy pulling 50 plus cars on my website. Some of those were Die Cast cars and some were old PW cars that pull hard.

And the limit was not the engine. It's all that would fit on the track without showing on the screen in front of the engine.

I really think it has most to do with "the most bang for the buck."

I have a MTH GP38-2 that I was working on.  In the process of the repair, I pulled one of the motors out.  Now it doesn't pull anywhere near what it did with 2 motors.  I think it mainly had to do with weight, and that small wheels are easier to break free and spin on the rail.

I also have the VL BB, and the K-Line BB.  The VL BB is scale, has one motor, and weighs more.  The K-Line is no scale, is lighter, but has 2 motors.  I'm pretty sure the VLBB could out pull the K-Line, but I'm not willing to chance breaking a coupler or ripping traction tires since you can't really get parts for the K-Line.  In regards to how they are built, there is no way you could do 2 motors in the VL BB due to how the front engine swings.  Now the K-Line BB, and also the RailKing articulated mentioned above, engines aren't mounted and thus swing like the prototypes do, so they can have 2 motors in them.

Thanks all