Differences in the Light vs Heavy Challengers

In William Kratville's volume The Challenger Locomotives (1980 Kratville Publications), drawings for the early challengers (6-axle tenders) show a length of 72' 7/8" for the engine alone (front coupler to end of engine bed); drawings for the later Challengers show a length of 74' 10-1/2" for the engine alone (front coupler to end of engine bed). That's close to a difference of 3 feet if I have read the small lettering on the reproduced drawings correctly.

Most of the difference seems to be in the much longer smokebox of the late challengers, which apparently was accommodated by shortening the tubes from 22' on the early engines to 20' on the later ones and by increasing the total engine length (minus tender: both early and late versions were about 122' overall, despite the different tender designs, as you said).

Thanks B Smith. I measured the boiler length (from the front of the cab to the front of the boiler) on both. 3839 was 14.25” and 3967 was 14.75”.

@Raven87 posted:

I’ve been searching to find why there is such a big difference in overall length of my Lionel Vision Line 6-11210 Challenger #3967 vs my newer Lionel Legacy 2331212 Challenger #3839.
#3967 is almost an inch and a half longer (locomotive only) from the rear of the cab to the front of the boiler than #3839.

The specs I’ve found online on the prototypes all say the length of all the UP Challengers was about 122’. I know about the class ratings  with CSA-1/2 being called ‘Light’  and then -3, -4, and -5 being ‘Heavy’ versions.

UP never referred to the locomotives as “lightl or “heavy”.  “Early Challenger” of “Fetter’s Challenger” for the first series.

Was there an actual locomotive-only length difference between the Lights and Heavies that isn’t mentioned or detailed online?

Yes.  They were completely different locomotives.

Or, is the difference because of comparing a Vision Line (#3967) vs a Legacy (#3839)? Or, is because 3967 is a coal burner vs 3839 being converted to an oil burner? I wouldn’t think so but cannot find the details that clarify why the Lionel units have a length difference.

Vision Line or Legacy has nothing to do with prototype length, as these are 3 rail “scale” locomotives and each were different length.

Are the actual Protoytpes that much different?

Yes, they basically shared the name and wheel arrangement “only,” all other aspects were different.

Below 3967 is on the top with 3839 at the bottom. It looks like the cab roof differences might account for some of the extra length of 3967?

Just like the prototype.

I love both units and operating both is a lot of fun!

As a side note, you should find a copy of the Kratville book mentioned above, an outstanding reference for UP Challenger locomotives.

Thanks 86TA. Great info.

And yes, I’m looking for that book (and others) about these magnificent locomotives.

I just bought one online. Looking forward to reading it.

I think you will really enjoy Kratville's book: it is very readable, not too big, has erecting drawings for each series of locomotives, and contains many excellent close-up photographs of mechanical details.

Thanks B. Should be here in a couple of days - looking forward to it.