I've always found the 4-8-2 to be a very interesting wheel arrangement as it was really the last wheel arrangement to come on the scene before the "superpower" way of thinking took off. It could be considered either a 4-6-2 with an extra driving axle or a 2-8-2 with an additional leading axle. Because of this steady arrangement, it is an arrangement suited well for both fast passenger and goods trains. For every railway using the type for express trains, there was another using it as a freight workhorse.
The very first true 4-8-2s were designed by D. A. Hendrie for the Natal Government Railways, as an extension of his earlier 4-8-0s with a larger firebox in 1909. The 4-8-2 there would become the most widespread type in all of South Africa. It is interesting to think about how the role of the 4-8-0 locomotive on South African Railways was much larger there than probably anywhere else in the world. The 4-8-2 is about as suitable an arrangement for South African conditions as there was (besides the garratts, but that's another story) , as four driving axles along with three leading/trailing was essential for plenty of adhesive weight meanwhile keeping axle loading down, on the lightly laid twisting rails that plagued South Africa the region over.
The first United States 4-8-2s were in the employment of the C&O as the J-1 design, in 1911. Unlike the Hendrie 4-8-2s, this was basically an enlarged 4-6-2 for passenger trains over the Appalachians.
The 4-8-2s used by the New York Central, the "Mohawks" were also an enlarged 4-6-2, essentially a K-11 type with an extra axle. But here the axle was used for heavy goods trains over flat terrain rather than extra adhesion in the mountains. The NYC system obviously took a liking to them, as 185 L-1s would be built starting in 1916, followed by another 300, as L-2s in the late 1920s all for goods trains.
The 4-8-2 caught on with more companies later on, with many being built in the 1920s. By the 1930s, many companies were moving on to 4-8-4s for heavy passenger with 2-8-4s and 2-10-4s for heavy goods, but some stuck with the 4-8-2 arrangement until nearly the end. NYC built 145 L-3 and L-4 Mohawks for dual service between 1940 and 1943, and the B&O were building 4-8-2s well into the 40s for heavy passenger service. The IC was another, once again using theirs for fast freight into the 40s.
Something I wonder about is how the 4-8-2 and 4-8-4 really compare overall. This is of course a fool's errand as there are so many variables between all the company designs of these arrangements. The 4-8-4 of course had the room for a larger firebox and consequently larger boiler, but adhesive weight on the drivers will be somewhat less with the addition of another trailing axle. A little more murky is the comparison of a 4-8-2 with a 2-8-4. The 2-8-4 was more exclusively a goods locomotive and by the time it was developing, one axle leading trucks were becoming more sophisticated in design allowing higher speeds.
Really it just comes down to what each company needed. There has to be a reason why some companies relied on hundreds of 4-8-2s for fast freight and why some were building them well into the 40s.
So, I'll end with this; what is your favourite 4-8-2 design and how do you compare the arrangement to later arrangements?
My favourite 4-8-2 have to be the NYC Mohawks by far, both the earlier goods ones and the extremely developed later dual serice ones. I'm also quite fond of the South African 4-8-2s, especialy the 15F, but this is an American forum so I won't go on.
B&O 4-8-2's were classy.
matthewsaggieB&O 4-8-2's were classy.
Never too old to have a happy childhood!
The NYC L-3a were probably the best looking American 4-8-2s in my opinion, probably the best looking American steam locomotives full stop.
Photo by Robert C. Schell, Jr.
CNR's Bullet nose Bettys were quite stunning and did yeoman service.
We should mention the PRR M1/M1a as being one of the most advanced designs leading up to the 4-8-4.
I'll see your cape-gauge African locomotive, and raise you N-zed-R Ja's...
Yeah Betty's ..fixed it. It happens. Been a stressful week.
CNR had little to no use for their monster fleet of 4-8-4's West of Winnipeg and especially in the Rockies were the mountain type prevailed and lived up to it's name.
The CPR ever being the complete opposite of the CNR only had 2 of them, never out West, and always in the East. Only 2 Northerns too!
Paterson-George Collection
Posing proudly with typical John Street polish, No. 2901, class I1a 4-8-2 stands for her portrait in the summer of 1932. This was in the days when good unobstructed photos could be shot of locomotives on the turntable. In later years heavy timber handrails were constructed along the sides after someone had fallen into the pit. The 2900 - 2901 were the only 4-8-2 Mountains on the CPR system. These two engines were built at Angus during July and August, 1914. They were built for passenger service and spent their lives on the Eastern Lines. The twins spent a big part of their lives at Toronto, where, in their early years they were assigned to the north end and were housed at West Toronto. They were not allowed to run downtown because of certain weight restrictions in effect at that time. They were uncoupled at West Toronto and a lighter engine hauled the train to the Union Station. In the late 1920s and 1930s they were assigned to John Street.
Overmod We should mention the PRR M1/M1a as being one of the most advanced designs leading up to the 4-8-4. And Vince, they're BETTYs. I'll see your cape-gauge African locomotive, and raise you N-zed-R Ja's...
And Vince, they're BETTYs.
I'll admit I don't know as much about the JAs compared to anything in South Africa, but I've always found it interesting how NZR already had a well-sized fleet of 4-8-4s and then decided to introduce more 4-8-2 designs after, which wasn't something that happened much elsewhere.
4-8-2s were a popular choice in general for 3ft 6inch gauge railways. You could find many examples on Australia's 3ft 6in network and Tasmania as well. The 4-8-2 was well suited for these sort of lines where large pulling power and adhesion was needed while keeping axle loading down.
An exception is Japan where they were more satisfied with 2-8-2 locomotives. Along with that, Japan was the one to introduce the true 2-8-2 arrangement. New Zealand was the one to introduce the 4-6-2 type too while I'm at it. It does make sense that some of the most versatile and adaptable wheel arrangements ever on later steam locomotives would have been born in the demaning conditions of the 3ft 6inch railways.
There were so many great 4-8-2 locomotives.
The Missouri Pacific 5335-5344 MT73 class were impressive.
The Rock Island M-50 4000s were mighty fine locomotives.
The Texas & Pacific 900s, Southern Pacific 4300s, Great Northern 2500s, and Florida East Coast 400s and 800s were very classy and effective units.
Seaboard Air Line had some special 4-8-2 units.
The list goes on and on.
https://www.steamlocomotive.com/locobase.php?country=USA&wheel=4-8-2
How about a double Mountain? East African Railways had 4-8-2+2-8-4 Garratts on their roster. https://www.world-railways.co.uk/general/photo/159
In a nod to our South African friend, I always thought the Great Northern 2500s with their Vanderbilt tenders bore similarities in their broadside view to the SAR 19D 4-8-2 units.
This beauty is preserved in Willmar, MN.
http://www.steamlocomotive.com/whyte/4-8-2/USA/photos/gn2523-krotzer.jpg
Here is a 19D with a similar sloped cab front and Vanderbilt tender.
https://www.google.com/imgres?imgurl=https%3A%2F%2Fupload.wikimedia.org%2Fwikipedia%2Fcommons%2F7%2F7e%2FSAR_Class_19D_2702_%25284-8-2%2529.JPG&imgrefurl=https%3A%2F%2Fcommons.wikimedia.org%2Fwiki%2FFile%3ASAR_Class_19D_2702_(4-8-2).JPG&docid=biHWgktKpSZXzM&tbnid=im10U6mmJ-hxcM&vet=1&w=1224&h=910&hl=en-us&client=safari&ved=0CA8QxiAoBGoXChMI2Oe4ltum3gIVAAAAAB0AAAAAEAs
Here is a a B&O 5500 with a Vanderbilt tender for BaltACD. Classy indeed.
https://www.american-rails.com/4-8-2.html
CSSHEGEWISCH How about a double Mountain? East African Railways had 4-8-2+2-8-4 Garratts on their roster. https://www.world-railways.co.uk/general/photo/159
4-8-2+2-8-4 was a popular arrangement for garratts in general, for the same reason the 4-8-2 was.
The EAR was the first to use the type but South Africa had the most I believe. The 8 members of class GL were the most powerful garratts of all, with ~89,000 lbs tractive force. The later GM/GMAM were the most numerous Garratt class of all.
The Soviet Union had a sole 4-8-2+2-8-4 Garratt that was dimensionally the largest ever constructed but I think came just short of the GL class in terms of power. Nothing ever came of it as the Soviets weren't used to the technology.
The most famous EAR 4-8-2+2-8-4 garratts were the class 59 which were the largest steam locomotives to ever run the metre gauge.
Gritty and underappreciated. The New Haven R-3.
OvermodWe should mention the PRR M1/M1a as being one of the most advanced designs leading up to the 4-8-4. . . .
"Many PRR men counted the M1 class locomotives as the best steam locomotives the railroad ever owned." - from: https://en.wikipedia.org/wiki/Pennsylvania_Railroad_class_M1
- PDN.
Didn't the 4-8-4 generally haver a large firebox that the 4-8-2? Thus it would have been able to achieve a bigger head of steam faster than its smaller cousin.. so overall the 4-8-4 would have been a faster more powerful beast.
The early posts in this thread discuss how a 4-8-2 could be the equal or better of a 4-8-4:
"PRR's M1 4-8-2 equal to a 4-8-4" - http://cs.trains.com/ctr/f/3/t/202112.aspx
It seems the PRR M1's Belpaire firebox design may have had something to do with that?
UlrichDidn't the 4-8-4 generally have a large firebox that the 4-8-2? Thus it would have been able to achieve a bigger head of steam faster than its smaller cousin.. so overall the 4-8-4 would have been a faster more powerful beast.
First, neither the speed nor the power of a locomotive is determined by its firebox size; in fact, a 4-8-4 will have higher weight and higher running resistance than a 4-8-2 of equal adhesive weight, cylinder dimensions and boiler pressure. The difference is in the radiant area in deep firebox and chamber that the two carrying axles permit, but that is significant in other ways. I realize this is a matter of the semantics you were using, but it's important not to confuse "more radiant uptake for steam generation" with higher performance.
It was well-understood in England that a good 4-6-0 could easily do the work of a Pacific ... up to a point, yes, but that point was far beyond what was required by actual normal train working. Some of this was circumstantial, but most of it involved great firing skill/experience, a consistent and high grade of coal, etc. It also reflects the ability of the 'locomotive' boiler to be significantly over-driven (in other words, show a high grate limit when economy is not considered) in ways that produce higher steam generation and practical superheat.
What the 4-8-4 gave, initially, was essentially the same thing that a Berk gave over an equivalent Mikado: better fuel economy for a given high performance level, more than enough to cover the added losses due to weight and length and so forth. In many cases this is more circumstantial than dimensional, as is illustrated even better by the reasons Lima proposed six-wheel trailers to make double-Belpaire "4-8-4s" even better performers. Most of the early 4-8-4s were, in fact, heavy freight engines of deplorable performance, and only the advent of better balancing practice (I think at about the same time high-speed practices were applied to simple articulateds) made them the equal of six-coupled locomotives for high-speed service -- which is the principal place their advantage over either 4-8-2s or 2-8-4s becomes compelling.
A bit of history is in order. The 2-8-2, 4-8-4 the 2-8-8-4 Yellowstones were pioneered in the US by the Northern Pacific. The NP was blessed with huge on line coal reserves in Montana, but it was poor quality lignite that required larger than then normal fireboxes to generate enough heat to drive the engine. Poor fuel forced larger fire boxes, which forced more trailing axles.
By contranst the Great Northern used either good Pittsburg Seam coal, or good British Columbia coal, or oil so they did not need the large fireboxes, and thus extra trailing wheels that the NP did. In fact, the GN actively avoided trailing wheels with its 2-8-8-0 N class locos, and built 2-8-2 engines with very high axle loadings and tractive effort.
Note that both the C&O and NYC had access to good coal and did very well with 4-8-2 designs. The point is, think about the quality of the fuel.
Up until the early 1920's, the NP was getting coal for Montana operations from Red Lodge and Bear Creek, with the Colstrip mines coming online about 1923. Red Lodge/Bear Creek coal was fairly good bituminous coal, with Colstrip being sub-bituminous (not quite as bad as lignite).
Did the 4-8-2 Mountains accelerate and pull well?
Which is better a 2-8-2 Mikado or a 4-8-2 Mountain?
I know SF had them.
ATSFGuyWhich is better a 2-8-2 Mikado or a 4-8-2 Mountain?
A 4-8-2 has a pin-guided leading truck, and a somewhat larger wheelbase meaning that it can be a larger locomotive and would be much more stable at speed than a Mikado with Bissel, right up to the era where high-speed Bissel trucks were devised for large power (as in the AMC locomotives and the N&W class A)
If you remember the past threads with Juniatha, the point was made that with sufficient thermodynamic 'improvements' the effective steam generation capacity of a normal single road locomotive could be made with structure that required only one carrying axle before and behind the driver wheelbase. That in turn would imply that a high-wheeled 2-8-2 (some roads had them, in particular the Great Northern O-7 and O-8 classes with 71" drivers) could do much of the work other railroads' 4-8-2s could. On the other hand, I'd expect that some components of augment would always be better-controlled by a pin-guided four-wheel engine truck than by an equalized two-wheel Bissel (see how Glaze implemented yaw stabilization on the N&W class J in order to facilitate low overbalance, for example) so for high speeds on less heroic track than required for an O-8 the 4-8-2 would, in its era, be preferable.
Naturally, even in the smaller load ranges the high-speed road-engine market was largely subsumed by the 4-8-4, which allowed fancy but heavy circulation arrangements in the radiant section, and somewhat less demanding fuel quality requirements, to be provided.
Note that NYC never went back to high-speed Mikados again after having participating in development of one of the most influential designs (Woodard's 8000) and building many examples in the early 1920s. Instead they went first to reams and reams of very competent 4-8-2s of increasing sophistication, then to a 4-8-4 notable for being able to provide 2-8-0-like fuel and water consumption when doing a 2-8-0's work, instead of wasteful overconsumption like the UP gas turbines when not producing the available 6000hp on tap at high speed every day that was a basis for Kiefer's comparison testing...
I was under the assumption that the comparison locomotive used in Kiefer's treatise was a three-unit E7 set, which led to one conclusion that the Niagara may have been too big for the service in which it was used.
Looking at the Great Northern O-8, notice that it manages a grate area of 98.50 sq ft and a tractive effort of 77,793 lbs which is well inside 4-8-4 territory with only a two wheel trailing truck. In my mind, if GN added a four wheel leading truck, they could have had a pretty good dual purpose locomotive.
I understand that the axle loading for this class exceeded what a lot of other companies could execute, but the fact that nearly a nearly 100 sq ft grate area could be made on a 2-8-2 kinda makes the claim that a 4-8-4 was clearly better than its predecessors more murky.
CSSHEGEWISCHI was under the assumption that the comparison locomotive used in Kiefer's treatise was a three-unit E7 set, which led to one conclusion that the Niagara may have been too big for the service in which it was used.
You'll benefit by actually reading the relevant sections of the 1947 report (it is a small volume).
Comparison is to BOTH two- and three-unit E7s, with the observation that the three-unit configuration was superior but MUCH more expensive.
All the Niagara's available horsepower was put to use in the particular service conditions of the test: high-speed long-distance service with heavy trains and short turnaround. None of the 'comparable' 4-8-4s in its size range could have coped with this; it would have been interesting to see what a N&W J as balanced could have done but of course the clearances were vastly inadequate to permit that.
Is that report available for reading/download? I'd love to take a look.
selectorIs that report available for reading/download?
Here you go:
https://catalog.hathitrust.org/Record/001615135
Nice photo of a New Haven 4-8-2 posted by Mr. Hebdo (Oct. 27) but it is an R-1-a not an R-3. The New Haven R-1 Class were USRA light mountain types in three sub-classes, R-1 3300-3309 (Richmond 1919), R-1-a 3310-3339 (Schenectady 1920) and R-1-b 3340-3348 (Schenectady 1924). The New Haven improved the USRA design with its R-2 3500 (Schenectady 1924) and R-2-a 3501-3507 (Schenectady 1926). The R-3 3550-3552 (Schenectady 1926) was similar to the R-2 but had three cylinders. It was followed by the R-3-a 3553-3562 (Schenectady 1928). The R-3-a was the last steam freight locomotive purchased by the New Haven and did a good job with heavy, fast freights on the Shore Line and other low grade mains until the diesels arrived. For a complete look at New Haven steam click the following:
http://sites.google.com/site/nynhhsteam
Paul_D_North_Jr The early posts in this thread discuss how a 4-8-2 could be the equal or better of a 4-8-4: "PRR's M1 4-8-2 equal to a 4-8-4" - http://cs.trains.com/ctr/f/3/t/202112.aspx It seems the PRR M1's Belpaire firebox design may have had something to do with that? - PDN.
Thank you for the link, Paul. This probably explained why PRR skipped building Hudsons and never wanted or needed a 4-8-4 for the passenger services. M1b was powerful enough and ready to handle longer passenger consists. Imagine roller bearings and rods, front end throttle, better balancing, poppet valves, and other cutting-edge technologies were applied to the M1s......
Jones 3D Modeling Club https://www.youtube.com/Jones3DModelingClub
Cotton Belt had a dozen mountain types, all of which were purchased second hand. The first five were small mountains originally purchased by the Florida East Coast from Alco in 1924. These were purchased from an equipment dealer in 1936 when the Florida land boom went bust. Cotton Belt converted them to oil firing and put them to work hauling its passenger trains. Another seven Alco mountains were purchased from the Rock Island in 1941. These were rebuilt and put to work hauling freight. All Cotton Belt mountain types were retired by 1953.
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