ever heard of a 2-8-6-2?

[Anonymous]

Its TRUE! Ive seen photos to prove it....well the museum does. we.. either a 2-4-6-2 or a 4-8-6-2, but the B&O DID have a test locomotive with different driving wheel arangement sets.

[Anonymous]

I seem to recall that one of the prototype PRR duplex locomotives was a 6-6-4-6? Am I mixed up in my old age???

[M636C]

trainheartedguy,

I think you have the B&O details a little confused, but the loco actually existed. B&O No 7400, class KK-1 2-6-6-2 built by Baldwin in November 1930, had running stability problems (described in the recent "Steam Glory") and it was rebuilt as a 4-4-6-2 class MK-1 in 1931, but was returned to original form as a KK-1 2-6-6-2 in 1933.

The Pennsylvania Railroad prototype Q-1 duplex was a 4-6-4-4, but the production Q-2 design was a 4-4-6-4. The change was due to moving the cylinders from the trailing end of the second set of coupled to the front, which allowed larger cylinders on the rear set. This allowed the bigger set of drivers to be moved back where they were most effective.

The Great Northern had a class of 2-6-8-0 locomotives built as such. Their boilers were re-used on Mikados in the 1930s.

The Santa Fe had a group of jointed boiler compound locomotives built as 4-4-6-2s, but after the interest in compounds waned, they were rebuilt as conventional 4-6-2s.

Hope this clears up the question of mixed coupled wheel arrangements.

Peter

[CSSHEGEWISCH]

The Q1 and Q2's were rigid-frame duplex drives, same as the T1 and S1. None of them were articulated. One of the European railroads did have a 2-4-6-2.

[jchnhtfd]

Pete -- it wasn't just the interest in compounds which killed the Santa Fe weirdos. There were some minor (!!!) maintenance problems connected with them... There was a time in there -- '20s, I think it was (my references are all at home) when Santa Fe had some really far out engines -- then they saw the light and went with a long string of really good successful conventional designs.

[Anonymous]

Ok. thanks Peter. I got my basic info from James Mischke of the B&O Historical Society. I think he had stated it was built as seen in the photo for testing, then partially scrapped after the testing failed, leaving most componants to build two later units.

[Anonymous]

Thanks Pete. I knew it had to be something like that.[:D]

[M636C]

I didn't mean to suggest that the PRR duplexes were articulated, although the other locomotives mentioned were all articulated.

The French locomotives mentioned were Paris-Lyons-Mediterranee class 151A. While to all appearances they were 2-4-6-2 rigid frame duplexes, they had cranks (at 90 degrees) on the adjacent axles of the two sets of drivers, with two inside coupling rods connecting the sets. They were thus (technically) 2-10-2s. Looking at a photo of 151A8 the two sets of drivers were connected 180 degrees apart, with the front outside rods at the top while the rear outside rods were at the bottom. This may have been to improve overall balance. These were compounds, with the low pressure cylinders on the front set of drivers. They also had Caprotti valve gear (or a similar type of rotary cam gear). The boilers were similar to the PLM and later SNCF 4-8-2s.

Peter

[kenneo]

QUOTE: Originally posted by M636C

trainheartedguy,

The Great Northern had a class of 2-6-8-0 locomotives built as such. Their boilers were re-used on Mikados in the 1930s.

Peter

M-2 Class 2-6-8-0 were built new as compound articulated locomotives in (1st order) 1910 and simpled in 1927. Original assignment was the 4% over Stevens Pass but they became redundent with the opening of the New Cascade Tunnel.

Nearly al of the M-2's boilers and cabs were used to build the O-7 and O-8 2-8-2's starting somewhere about 1931 or 1932 and the conversions were completed at Hill Yard (Spokane, WA) during WW2 or shortly after.

In 1950, there were still 11 M-2's operating. After they were bumped by the electricts, they went to the Great Falls-Butte line (track since removed - some years back) and anyplace else where their top speed of 25MPH was adequate for the service required.

Above from "Lines West" by Charles R. Woods and published by Superior Publishing Company of Seattle WA 1967.

[Anonymous]

Southern Railway had three 2-6-8-0s. They were not considered successes. They were AGS 300, later renumbered CNO&TP 6399, and 4002 and 4003. They were class Ls and were scrapped during the depression.

I also believe the B&O had a 2-6-8-0.

[mudchicken]

QUOTE: Originally posted by jchnhtfd

Pete -- it wasn't just the interest in compounds which killed the Santa Fe weirdos. There were some minor (!!!) maintenance problems connected with them... There was a time in there -- '20s, I think it was (my references are all at home) when Santa Fe had some really far out engines -- then they saw the light and went with a long string of really good successful conventional designs.

The front and rear sections were re-cabbed and turned into switch engines. There are enough of them out there "stuffed and mounted" in city parks that you could re-create them. Except for the ex-N&W Y-2 Class engines on Raton Pass in WWII, this was ATSF's last fling with articulateds. Trains photo essay of a few years ago nominated them for the "mud-fence award" (?) along with the U30-CG's...They could be classified as successfull failures.

Rock Kickin MudChicken..
[|)][|)][|)]

[bowlerp]

Yes, The Erie Railroad once made a 2-6-8-2 from the frame and engines of one of the three 0-8-8-0 Camelback Articulated Helper locomotives they made in 1907. The 0-8-8-0 trio lasted about 8 years, then two of them were re-made into 2-8-8-2s, while the one unti was made into the odd duck as described. I don't think any of them were successful after the re-builds from the original Camelbacks, reputed to actually work and run fairly well in helper service.

[UPTRAIN]

drephpe, I think you are correct. I think I have seen a pic of that in a book, you got a road number?

[M636C]

Guys,

I've checked through a couple of references, and found that the B&O had a 2-6-8-0 as well as the 4-4-6-2/2-6-6-2 described above!

One of the class E-24 2-8-0s built to Pennsylvania design (PRR H-6, I think) complete with a Belpaire firebox, was converted to a 2-6-8-0 by the addition of a jointed boiler (with feed water heater) and a compound "2-6-0" section added forward of the original cylinders. This work was done by Baldwin in 1911, but the loco reverted to a 2-8-0 later (maybe 1917). While a 2-6-8-0 it was class KL-1, but was numbered in the middle of a group of 0-8-8-0s. It isn't listed in the Kalmbach "Steam Locomotive Guide", at least not in its converted state.

I'm not sure whether forward boiler section moved with the engine unit (as it did with some contemporary ATSF locos, or whether it was fixed as in a normal Mallet. It didn't have visible "accordion" connections.

Sorry I missed this first time. The 1930s conversion is much better detailed in both references.

Peter