Largest eight driver steam engine????

Model Railroader General Discussion (Model Railroader)
1

Good morning. [:D]

Does anyone know what was the largest loco with eight drivers? Would UPs’ 4-8-4 qualify?

Thanks

Lee

2

I believe that the distinction of the largest 8-coupled locomotive goes to Uncle John Santa Fe’s Northerns. Due to wartime restrictions on lightweigt steel alloys their models built during WWII–2900 Class?–were, without a doubt, the heaviest.

3

The Pennsylvania S1 6100 had eight driving wheels.

It was about the same size as a Big Boy although not as heavy.

It was much longer than any 4-8-4 and heavier too. Those six wheel trucks were to carry a greater load than a four wheel truck.

It wasn’t called “The Big Engine” for nothing…

M636C

4

Yes, at 140’ in length the 6-4-4-6 was truly a “Big Engine”. It may have been a one of, but still quite the engine and it did mainline duty. It was also the subject of many speed records, unfortunately they could not be verified.

5

The reason I ask about the 4-8-4s’ is because I’ve been thinking about getting a large 4-8-4. I have just about had it with articulated locos and Bachmanns’ on board sound. I am sure almost everyone has heard of my 2-6-6-2. It’s still junk. [|(] If I don’t get mad enough to throw it against a wall I might put a good decoder in it.
I’m trying to determine whats available.

Have a good day[:)]

Lee

6

This link might help

http://www.steamlocomotive.com/misc/largest.shtml

7

Lee:

First of all, what’s your minimum radius? Remember, some long wheel-based NON-articulated steam locos need a wider radius than a lot of current articulateds. 4-8-4’s can be tricky on tight radii, especially the lead and trailing trucks.

Out in the west here, we had some pretty hefty 4-8-4’s–Santa Fe, Southern Pacific, Union Pacific, Northern Pacific and Great Northern sported some really BIG ones–often much bigger than 4-8-4’s in the Midwest or East. Long wheelbases, tall drivers (up to 80"), and lots of room under big, extended fireboxes.

Commercially, a lot of current plastic 4-8-4’s are rated at between 22-24" radii, but the overhang (particularly between cab and tender) is tremenduous on those smaller curves.

Remember, most plastic articulateds are DOUBLE-articulated (unlike the prototype) which eases them around tight curves. Long-wheelbased non-articulateds aren’t, and the overhang is TERRIFIC on smaller radii.

If you’ve got a 24" or larger radius, the ‘smaller’ (and I use that word with caution) Santa Fe 4-8-4 from BLI looks okay. But under that, most any commercial 4-8-4 is going to look not only awkward, but probably won’t track well. Especially the bigger current SP or UP models.

8

I am not sure myself but I have a drawing on my wall of a BALTIMORE AND OHIO EM12884

Here are the specs.

  1. Weight of Engine: 628,000 lbs.

  2. Weight of Tender 304,000 lbs.

  3. Tractive Effor 115,000 lbs

  4. Drive Wheel Diameter: 64"

  5. Boiller Pressure: 235 lbs. per sq. in.

  6. Length of Engine & Tender 125Ft- 35/8"

  7. Tender Capacity: 25 tons or 22.000 gals

  8. Road Numbers 7600 to 7629

9

BALTIMORE AND OHIO EM 1 2 8 8 4 : Built by Baldwin Locomotive Works 1945

  1. Weight of Engine; 628,700 lbs

  2. Weight of Tender: 304,000 lbs

  3. Tractive Effort: 115,000 lbs

  4. Drive Wheel Dia. 64"

  5. Boiler Pressure: 235 lbs per sq in.

  6. Length of Both &

10

Thanks Everyone.
I got the information I was looking for, and some that I didn’t want.
You all are right about the overhang on the ridged eight driver locos.
My 4-8-2 heavy mountain should have alerted me to that fact.
My curves are 20" to 24" except for the reverse loop which is 18".
They all will make the reverse turn, even the 2-6-6-2 but the 4-8-2 will clip a building if I try to back it through. [|(]
I suppose that rules out the heavy Iron.
It was all good information, thanks again. [tup]

Lee