Lionel Union Pacific GP30 O Scale Locomotive #844 That Was Produced Around The Year 2000.

Actually Ed, there is a precedent for your engine; the Lionel #28249 AT&SF U28CG headed up a set produced early in the century. It was produced with a single drive axle on each six wheel truck. The single drive axle is the center axle on this loco. It has the traction tires on the center axle  and runs just as good as my other diesel locos and pulls whatever I've put behind it. I will admit I don't have any steep grades so won't comment on that aspect.

Are you speaking of the scale version or the 'toy' version? I have the scale NYC GP30. I believe there are two motors & pick-ups under the trucks... the 'toy' versions are usually GP20 or GP38 which have one motor/pick-up

To Dave P:

I was mistaken, the locomotive in question "is" the O scale version of the Lionel Union Pacific GP30 with a cab number of 844. It has only one powered axle on each truck. The powered axle is the inner axle, the one with the rubber tires however it seems to have the same tractive effort as my New York Central GP30. This GP30 also has different truck center pieces and pickup assembly from that of New York Central GP30 . The New York Central GP30 and it has two powered axles per truck.

Ed New Haven Line

You got me curious so I found a picture here on OGR (disregard the pickup roller).  Here  you can see that the only one of the axles is driven. 

This engine, No. 28860, was actually cataloged in 2005. I have it (and the dummy) as well. Beautiful, full scale engine. The truck design (I think they called it LionDrive) was a newly redesigned one, and was used on various other scale engines at the time as well. They had a single powered axle on each truck. Lionel indicated it was much easier to work on and to remove for repairs, among other claimed advantages. I recall that there was a full page article in Classic Toy Trains about it at the time, and the revised truck design received a very positive review.

Despite having only single axles powered per truck, these engines pulled just fine. Nonetheless, there was an outcry at the time from operators who demanded a return to two driven axles per truck. They complained that Lionel was cutting corners, and that the new design must result in less pulling power. Eventually, Lionel bowed to the pressure, abandoned the new truck design, and went back to a design with two axles driven per truck. 

If one wanted to spend the time, and if the Forum search function goes back that far, it might be possible to go back and look at the threads about this at the time - there were a bunch of them. 

To Breezinup:

Now that you mention the LionDrive system I do remember Lionel trying that. I was working with a friend from 2000 to 2017 at that time at his train store that he still owns where I purchase that engine. As mentioned I also have the New York Central engine of the same model and both axles are powered.

Ed New Haven Line

@ed new haven line posted:

To Breezinup:

 As mentioned I also have the New York Central engine of the same model and both axles are powered.

Ed New Haven Line

The New York Central GP-30 was cataloged in 2004, a year earlier than the Union Pacific GP-30. The new truck design wasn't being used yet, apparently.