Steam & Excursion > How Much Bigger, 4014 versus 3985?

Without doing some research I'm curious how much bigger the Big Boy is compared to the Challenger. OK, so we've got more drivers and its longer (by how many feet?) but what about other statistics? Do they have the same tenders? And please don't tell me I can look it up. It might make interesting conversation.

Well you could look up a few basic things for start, but since I'm avoiding doing some other things I should be doing this morning I'll paste in a few:
All info from upsteam.com unless another source noted

3985 vs 4014

Cylinders:
3985: Diameter: 21 in. Stroke: 32 in.
4014: Diameter: 23 3/4 in. Stroke: 32 in. (2 3/4 inches bigger in diameter)

Driving Wheels:
3985: 12 x 69 inches in diameter
4014: 16 x 68 inches in diameter (1 inch smaller wheels but it has 4 more of them)

Wheelbase:
3985: Engine & Tender: 121 ft.10-7/8 in.
4014: Engine & Tender: 132 ft. 9 7/8 in. (9% longer)

Total Engine and Tender Weight :
3985: 1,063,500 lbs ((from steamlocomotive.com)
4014: 1,250,000 lbs (from wikipedia) - (117.5% of 3985)

Boiler Pressure:
3985: 280 psi
4014: 300 psi (20 more pounds in 4014)

Firebox:
3985: Length: 187-1/32 in. Width: 108-3/16 in.
3014: Length: 235 1/32 in. Width: 96 3/16 in. (About 26% longer but about 11% more narrow than 3985)

Evaporative Surface (square feet):
3985: Tubes: 527, Flues: 3,687, Fire Box: 500, Circulators: 81, Total: 4,795
4014: Tubes: 967, Flues: 4,218, Fire Box: 593, Circulators: 111, Total: 5,889 (Overall 118% that of 3985)

Superheating Surface (square feet):
3985: 2,162
4014: 2,466 (114% that of 3985)

Tractive Effort:
3985: 97,350 lbs.
4014: 135,375 lbs. (39% higher than 3985)

Factor of Adhesion:
3985: 4.17
4014: 4.00

To me these locomotives seem to be really similar except that 4014 is like a challenger that has been stretched a bit to accommodate two more driving wheels, with a bigger boiler and other tweaks to make even more power on 16 drivers and 4 cylinders. They seem to have the same visual style, the same type of valve gear, almost the same size cylinders and driving wheels, etc. The Big Boy certainly seems like the big brother of the Challenger.

Wikipedia seems to echo this.
---------
Led by mechanic Otto Jabelmann, the Union Pacific Railroad's design team worked with the American Locomotive Company to re-examine their Challenger locomotives. The team found that Union Pacific's goals could be achieved by making several changes to the Challenger design, including enlarging the firebox to approximately 235 by 96 inches (5.97 m × 2.44 m) (about 155 sq ft or 14.4 m2), lengthening the boiler, adding four driving wheels and reducing the size of the driving wheels from 69 to 68 in (1,753 to 1,727 mm).
---------

I recall someone here genuinely scoffing at the idea that a Big Boy was a sort of stretched Challenger. It seems that's exactly what it is. An enlarged Challenger.


-K

THANK you, Kurt, for the comparisons!
My son has been saying for years that a
UP Challenger is "a portable Big Boy".
He is right!

Fascinating comparisons! Thanks, again,
for going to the trouble of looking up all
those fascinating facts and for putting them
into a very readable format.

Kurt, thanks for posting the data. I have said all along that the Big Boy was an expanded challenger designed for heavier freight out in western Wyoming and eastern Utah. They were designed for the Wasatch grade and at onetime were about to don the moniker of the "Wahsatch Class". Thank goodness for the worker at Alco who chalked that name on its smokebox door. It would be interesting to have a chance to feel the operating characteristics of the Big Boy compared to the Challenger and Northern I used to operate.

The Challenger could dig in and start trains up easier than the Northern as the Northern would tend to slip with the heavier input of steam to the cylinders and the higher diameters of its drive wheels. Once the speed was increased enough, the 844 would take off to attain the higher speeds. But with constant attention to the locomotive one could keep the Northern on the edge of slipping and increase the speed fairly fast. Locomotives will tell you what they feel like. I am sure that Don (Frisco 1522) or Ross, Bobby and others who have operated the finest of steam will tell you the same. Listening to the locomotive lets you know when you can increase or that you have to decrease steam to the cylinders. This is why engineers gave human characteristics to the ones they operated.

I would ask Engineers I worked with about the UP class 9000's and they all told me that those locomotives could really hold the rail. They could get down to around 4 or 5 MPH over Archer with a long drag freight and never slip or stall. That was the three cylindered 4-12-2's of UP fame. The 9000 still remains on display at the Rail Giants in Pomona.

We enough pondering on the subject. Back to the easy chair.

Bob Krieger
Cheyenne, WY

Bob3985 Wrote:
-------------------------------------------------------
> Kurt, thanks for posting the data. I have said all
> along that the Big Boy was an expanded challenger
> designed for heavier freight out in western
> Wyoming and eastern Utah. They were designed for
> the Wasatch grade and at onetime were about to don
> the moniker of the "Wahsatch Class". Thank
> goodness for the worker at Alco who chalked that
> name on its smokebox door. It would be interesting
> to have a chance to feel the operating
> characteristics of the Big Boy compared to the
> Challenger and Northern I used to operate.
>
> The Challenger could dig in and start trains up
> easier than the Northern as the Northern would
> tend to slip with the heavier input of steam to
> the cylinders and the higher diameters of its
> drive wheels. Once the speed was increased enough,
> the 844 would take off to attain the higher
> speeds. But with constant attention to the
> locomotive one could keep the Northern on the edge
> of slipping and increase the speed fairly fast.
> Locomotives will tell you what they feel like. I
> am sure that Don (Frisco 1522) or Ross, Bobby and
> others who have operated the finest of steam will
> tell you the same. Listening to the locomotive
> lets you know when you can increase or that you
> have to decrease steam to the cylinders. This is
> why engineers gave human characteristics to the
> ones they operated.
>
> I would ask Engineers I worked with about the UP
> class 9000's and they all told me that those
> locomotives could really hold the rail. They could
> get down to around 4 or 5 MPH over Archer with a
> long drag freight and never slip or stall. That
> was the three cylindered 4-12-2's of UP fame. The
> 9000 still remains on display at the Rail Giants
> in Pomona.
>
> We enough pondering on the subject. Back to the
> easy chair.

Thanks for the good info. I recall the 844 slipping her drivers on the way out of Kemmerer back in 2010. All I could think of at the time was how powerful the 844 was. I know it takes alot of horsepower to do that. Are you going out see the 4014 too?

Posted from Android

Bob3985 Wrote:
-------------------------------------------------------
> Kurt, thanks for posting the data. I have said all
> along that the Big Boy was an expanded challenger
> designed for heavier freight out in western
> Wyoming and eastern Utah. They were designed for
> the Wasatch grade and at onetime were about to don
> the moniker of the "Wahsatch Class". Thank
> goodness for the worker at Alco who chalked that
> name on its smokebox door. It would be interesting
> to have a chance to feel the operating
> characteristics of the Big Boy compared to the
> Challenger and Northern I used to operate.
>
> The Challenger could dig in and start trains up
> easier than the Northern as the Northern would
> tend to slip with the heavier input of steam to
> the cylinders and the higher diameters of its
> drive wheels. Once the speed was increased enough,
> the 844 would take off to attain the higher
> speeds. But with constant attention to the
> locomotive one could keep the Northern on the edge
> of slipping and increase the speed fairly fast.
> Locomotives will tell you what they feel like. I
> am sure that Don (Frisco 1522) or Ross, Bobby and
> others who have operated the finest of steam will
> tell you the same. Listening to the locomotive
> lets you know when you can increase or that you
> have to decrease steam to the cylinders. This is
> why engineers gave human characteristics to the
> ones they operated.
>
> I would ask Engineers I worked with about the UP
> class 9000's and they all told me that those
> locomotives could really hold the rail. They could
> get down to around 4 or 5 MPH over Archer with a
> long drag freight and never slip or stall. That
> was the three cylindered 4-12-2's of UP fame. The
> 9000 still remains on display at the Rail Giants
> in Pomona.
>
> We enough pondering on the subject. Back to the
> easy chair.

Thanks for sharing. It's hard to be around a fired up steam locomotive and not imagine it is sort of alive.... breathing, talking, living. So much power via a purely mechanical boiling water machine. I can only imagine what it's like to be at the helm of these engines. A tiny little throttle time with 765 is the closest I've come. A 9000 alive at full power would be something to behold.
There was an episode of BBC's Top Gear that featured a race between a steam locomotive, a car and a motorcycle. In it, the 4-6-2 60163 Tornado does a little slipping at 70MPH and Jeremy Clarkson is amazed at the slipping at speed.

-K

IIRC, the design went the other way around. The Big Boys weren't scaled up Challengers so much as the later Challengers were scaled down Big Boys. UP had received two orders of 4-6-6-4s in the late 1930s, the "light" Challengers, which were similar to other 4-6-6-4s on other railroads, including the Western Pacific.

The first Big Boys arrived in 1941 and the UP and Alco redesigned the Challengers with features from the Big Boys, leading to the last three orders of "modified" or "heavy" Challengers. I think the Clinchfield also had 4-6-6-4s of this style.

I'm going off memory, so I may be all wet here.

Z

Thanks for the info Kurt.

kurt765 Wrote:
-------------------------------------------------------
> Well you could look up a few basic things for
> start, but since I'm avoiding doing some other
> things I should be doing this morning I'll paste
> in a few:
> All info from upsteam.com unless another source
> noted
>
> 3985 vs 4014
>
> Wheelbase:
> 3985: Engine & Tender: 121 ft.10-7/8 in.
> 4014: Engine & Tender: 132 ft. 9 7/8 in. (9%
> longer)
>

Hi Kurt,

Thanks for posting the info for the 3985 and 4014.

No bone to pick with you. It looks like the numbers that are on the UP Steam website for the wheelbase for both 3985 and 4014 are actually the overall length and not the actual wheelbase numbers for either of the locomotives. Maybe someone made a mistake transcribing the numbers from the drawings, for the website?

What got me a bit perplexed, with the numbers, is that Big Boy locomotives were turned on the Cheyenne turntable routinely without any problems. There are lots of photos and motion picture film of them being turned back in the day.

Reportedly the length of the Cheyenne turntable is 126 feet. A wheelbase of 132+ feet means that a Big Boy could not be turned on the Cheyenne turntable, but photos show the Big Boys being turned there. A wheelbase of 121+ feet for the Challengers would be doable but still a bit snug on length.

The UP locomotive drawings in the Kratville books show different numbers for the wheelbase, but the overall length for both engines on the drawings match what is shown on the UP Steam website for the wheelbase. A misread of the info on the drawings during transcription would be my guess as to how the incorrect numbers ended up on the website.

From the drawings:

Overall length, coupler face (locomotive front) to coupler face (tender rear):

3985: 121 ft. 10-7/8 in.
4014: 132 ft. 9-7/8 in.

Wheelbase, for both locomotives, as measured from lead axle center on the engine truck (pilot truck) to center of rearmost tender axle, per the drawings:

3985: 106 ft. 8 in.
4014: 117 ft. 7 in.

My 2 cents for the discussion.

Bob

Don't forget they jacked the tenders to turn them at a few places.
The Clinchfield Challengers came from the DRGW via the war board. UP engines diverted for the cause.

Posted from Android

Bob: Yeah I was thinking those numbers must be overall length too. Makes sense that their "wheelbase" figure is really the full length.

SD45X Wrote:
-------------------------------------------------------
> Don't forget they jacked the tenders to turn them
> at a few places.
> The Clinchfield Challengers came from the DRGW via
> the war board. UP engines diverted for the cause.
>
> Posted from Android

Quite right.

The jack the rear tender axle and shim the journals of that axle method was used at some terminals that normally did not see the larger locomotives, Big Boy and Challenger. Doing That would shorten the wheelbase by six feet and allow the use of a turntable that was a wee bit too short for the locomotive being turned. That process could be done in a few minutes.

The current steam crew used the same method on 844 during a backing move on the approach to the California State Railroad Museum during their last visit to Sacramento, CA. They found a newly installed curve (by UPRR) was a bit too tight for the tender to negotiate, with the rearmost tender wheelset on the rail.

Cheers!

Bob

A friend says:
Similar to 'turning' the Mallets at Taylor Yard in the late '40's. There was not much room left on the turntable track for all the wheels. He would watch them turn and being serviced on the way thru the yards to the swimming hole in the L A River.