Union Pacific Big Boy 4-8-8-4 / Challenger 4-6-6-4
(2011-??)

I suppose that every model railroader at some point or another gets the itch to want to have the biggest of the big, the world's largest steam locomotive as it is commonly billed: The Union Pacific 4000 Class "Big Boy" 4-8-8-4. Big Boys come with a list of superlatives. You can read up on them over at SteamLocomotive.com. One does not really begin to realize just how big ones of these monsters are until he gets up close next to one--that's me at the right next to #4006 at the National Museum of Transportation outside of St. Louis, Missouri (and with boots on I am nearly 6'-4").

With the construction of a Big Boy, Doug will again have achieved another first in F scale: The first UP steam locomotive model and the first Big Boy (obviously).

Concurrent with the Big Boy will be two second generation, Otto Jabelman designed Challengers. One of the two will of course be the 3985 with oil fuel tender. So far this project is moving along quite well with most of the centipede tenders having already been cast by Barry Bogs. Bill Brisko's wax rapid prototype machine has already produced the driver center patterns, but read on to find out more. . .


With Even More Help From My Friends

Doug's usual gang of suspects will be at work on both the F scale Big Boy and the very similar Challenger. So far that accounts for eight people, nine counting  Mr. Gary Bartlow who has commissioned not one but three Big Boys!

● Dave Queener of Cumberland Model Engineering (your host) is responsible for machining and assembling the 68" & 69" drivers, main & side rods, lead truck, and rapid prototype trailing truck.

● Michael Aronson is drawing chassis in CAD.

●  Bill Brisko of Pacific Locomotive Works is providing the Boxpok driver center castings for the two classes of UP locomotive as well as 36" and 42" steel wheels for the lead, trailing & tender trucks.

● Rodney Eddington of R and K Railroad Products will be milling the frames and assembling the chassis.

●  Ward Hammond will be laser cutting the cabs from styrene.

●  Barry Olsen of Barry's Big Trains has provided the double reduction gearboxes (four per locomotive).

●  Barry Bogs has made styrene patterns and cast the centipede tenders for both the Big Boys and the UP Challengers in urethane. Barry is also doing the battery, Airwire and sound installations.

●  Doug Hemmeter of D&M Railroad Backshop is doing all the rest!

Drawings for this project have come from several sources: First, Roger Goldman offers both Big Boy and Challenger drawings from his extensive collection (as well as 1.5" scale castings for the same). Secondly, Samhongsa in Korea has produced the two locomotives in brass, each in 1:32 scale (once again a good model is worth a words and a few dozen drawings). Finally, additional material has been garnered from the model railroad press.

Barry Bogs Finishes 1st UP Centipede Tender

Barry Bogs was tapped in mid-2010 to build the 5 centipede tenders for the UP Big Boy / Challenger project coordinated by Doug Hemmeter and commissioned by Gary Barlow. Barry has sent in a steady stream of photos as he has gone from styrene master patterns to production urethane castings and then completed and painted models. Here are the results thus far:

And here is a comparison with respect to size: First the F scale centipede tender by Barry next to the Samhongsa 1:32 tender; next, the same tender in F scale next to two of the F scale D&RGW M-68 tenders. Centipede tenders were indeed goliaths of the rails!

Last update: 9 December 2011