A bit thing you are missing here is while they ended up being pusher (banking) engines, that's not what they were intended for. (I manly learned about the Virginian 700, but I believe the Erie 3 where of the same reasoning) These were designed for Coal Drags, which don't need much in terms of speed, but did tend to need more than single digit top speeds. The want was for one big engine (and thus one crew) for these and to pull ever larger drags. But when they couldn't provide enough steam for the journey they were dropped down to pusher service. However in the US pusher service wasn't really anything special, a standard engine or two was typically enough for this and the benefits of a special engine for this was greatly outweighed by the costs.
The VGN seemed to like using single engines on their coal drags from Roanoke to Norfolk as it was generally down hill for loads and hence why they used 2-10-10-2s for a time after the Triplex (eventually they were supplanted by the AG class 2-6-6-6 when a former C&O employee became their mechanical officer in the 40s)
And another note The Virginian 700 was a 2-8-8-8-4 and all for Triplexs on both Railroads were remade to make several different 8 driving wheel locomotives. the Scrap logs were mainly for the Boilers and I think the Virginian scraped 700's tender also I for get the road numbers but the 700 was remade into three 2-8-0 loco motives.
@@Dallen9 VGN 700 was actually split into a 2-8-8-0 and a 2-8-2 (they were AF Class 610 and MD Class 410 respectfully, a lot of websites would confirm it)
I think with better trained crews and a bigger firebox and a condensing tender like the south African Class 25 4-8-4s and the German BR52 2-10-0's instead of simply injecting the steam back into the last set of drivers this locomotive would have worked.
Both the Erie and the Virginian were entirely intended as pushers. The Erie locomotives spent their entire careers on their one 7.75 mile grade. The Virginian never entered service.
@@brokkrep No, they're called tank engines because the water TANK is incorporated directly into the body of the engine, rather than being in a separate tender
0:17 "Each bogie was powered with three cylinders giving the Big Boys a significant amount of power" - No, and no! The Big Boys had one fixed engine unit (set of driving wheels) at the rear, and one swivelling engine unit at the front, which you could call a 'bogie' at a stretch. That was the '-8-8-' bit. The actual bogies (aka trucks) would have been the carrying wheels at each end, hence 4-8-8-4. And the engine units were twin cylinders, hence 4 in total. 0:40 "These boasted three cylinders per bogie" - again, no. So far as I'm aware, the Triplexes only had two cylinders per engine unit, also. This is why the UP 9000 4-12-2's - which did indeed have three cylinders - were such a notable exception in large US steam locomotive practice.
There are only 4 remaining American built locos with 3 cylinders: UP 9000, Southern Pacific 5021, Alton & Southern 12, and Baldwin 60000. Of those only the first 3 had conjugated valve gear installed. There were never any articulated American locos with more than 2 cylinders in each engine.
One other issue the Triplex had was that, as it used its coal and water, the driving wheels under the "bunker" would lose traction and slip often because the weight of the coal and water pushing down on those particular driving wheels would drastically reduced the long the locomotive ran
this was the main issue if why the Tri-Plex locomotives never caught on, besides the poor steaming and heating issues, they were never very fast nor could go very far. This is why the Big Boy was so successful, was being a normal simple articulated, and his massive size, was why it could pull so much. It was just a natural progression from the Challenger locomotives that UP went back to ALCO and asked if they could make it bigger. During the build of the locomotive an unknown builder scribbled Big Boy on the boiler, owing to the fact it was one effing huge locomotive. As we all know, the name stuck and the rest is history.
@@SirLANsalot Related to the Big Boy, a good documentary about them and their history of how they came to be and ran is called "Last of the Giants" and was produced by the Union Pacific. Worth a watch
I know the problem of you all, read only the normal books. First, the Tender had a higher axleload than the loco and a diffrent valve seting for less tractive effort. This could prevent more wheel slipping than the loco.
Another problem with the triplexes I'm surprised you didn't mention: As the fuel reserves were depleted the driving wheels under the "tender" became much more prone to slipping, so power would have to be reduced to all the drivers as the tender set did not have their own throttle valve.
Excellent point. Weight on drivers is a significant factor in overall tractive effort. The variability in weight of both water and fuel bearing down on the rear set of drivers was a major oversight by the designers. But one must admit, the Triplex was an extremely interesting concept, and made for one hell of an impressive sight with its 24 driving wheels under one boiler!
@@davidrayner9832 All of the weight of the boiler/cab assembly were applied to the driving bogies, which helped mitigate the loss of weight from water and fuel depletion. But I'm sure it definitely had an effect, though it wasn't like the only weight over a set of drive wheels was water and fuel weight, like the Triplex.
The Big Boy only had four cylinders-two on each engine set. Also, only the front set articulated; the rear set was rigid with the boiler and cab. Though, the Union Pacific did build a series of 4-12-2 locomotives that had three cylinders. One of them, #9000, survives today.
@@RacoonySkaloonyOfficial in Europe most did have inner pistons, in the United States they where used on only a small handful of types but the majority of engines here had only 2 cylinders per set of drivers.
@@RacoonySkaloonyOfficial Even worldwide, no. You could argue that there were more inside valve gear designs than outer, but there were definitely more outside piston locomotives.
Union Pacific had a small number of 4-10-2 three cylinder locomotives. They were near duplicates of the Southern Pacific's 4-10-2. In the 30s or 40s the center cylinder was deactivated. The 4-12-2s out lasted them into the early fifties. If you want to see many strange locomotives check out Loco-Locomotives in the Retro-Museum website.
There is a (claimed) story that when a Triplex pulls a heavy train, possibly heavy freight, the locomotive pulled so strong, the couplings of the cars and trucks of the time could not withstand the power and, possibly, broke under pressure. That’s why they were used afterwards to push not to pull. Interesting story.
I would have thought it is more likely a myth and only couplings that had manufacturing defects broke. No expert so feel free to tell me if you think I'm wrong.
i believe that it was not the couplers themselves that broke but the frames of the cars they were mounted to due to wooden frames the stress of that many cars pulling on them split frames
Big Bertha (UK banking engine covered on this channel) occasionally snapped couplings or crushed freight wagons when being used so I believe other engines could do the same
This happened with the NZR G class (1928) which were a Garratt: 4-6-2+2-6-4 with 6 cylinders. They eventually just gave up and scrapped them but it's rather funny that NZ managed to build a locomotive too powerful for it's cars.
A couple of things that you missed: *Too Much Power* - The Erie was the first to have Triplexes built. Named "Matt H. Shay" in honor of a beloved employee of the railroad, it was originally intended to pull trains up the steep grades on its own. During testing, it was pulling a train of 250 cars up an incline. The journey went well, until they hit the 17 mile mark; here, a coupling snapped, and the train was ground to a halt. Investigation found that the engine was so powerful that the shock of just normal operations was enough to literally tear apart rolling stock. Undeterred, they decided to instead have it serve as a banker. *Virginian Woes* - While the success of the Erie's triplexes is generally considered uneconomical at the best of times, the Virginia Railroad's sole example was far less successful. The XA (numbered 700) was designed to drag up to 10 miles an hour, but it was found that anything beyond ~5 mph would empty the boiler of steam faster than it could be produced. Despite actual personnel from Baldwin stationed where the engine was kept to try and assist in hammering out the problems, it just simply didn't work. Worse still, the VRR found them even less reliable than the ones that the Erie were using. In fact, 700 in general was disliked by the crews. *Too Much Puff, Not Enough Steam* - _Matt H. Shay_ was given a 90 sq ft. grate area for the firebox; this proved insufficient, and so both the second and third received a 122 sq ft. grate area. Despite this large increase in size, it still wasn't enough to satisfy the demand the driving wheels provided.
I believe that one of the first engines with Stoker and a Feed water pump could have Problems with this. The matt h. shay had a Piston pump and got a turbo pump later like the other triplex. There was a Erie engineer who said: " If the water pump get enough water in the Boiler ,we have enough Steam."
@@martinanschutz7410Good, I feel like the drafting issue could be improved by using a modern exaust layout (klychap, lempor, ETC) and a double/triple chimney setup
@@Combes_ of course, yes . But i think all parts of the Steam curcuit need to bei improved. The triplexes are at the time of a N&W Y2. The improvements of a Y6b would make them great.
the triplex's problem was the mechanical stoker, (all mechanical stokers had the same problem) they could not spread the coal evenly nor cover the grate fully, and thus limited steam production; the draft and grate size were sufficient, this was demonstrated when the mechanical stoker on one of the Erie triplexes broke down and they hand fired the boiler
"Just don't expect to see anyone building one anytime soon" To be fair, nobody expected a new build PRR T1 either. Although, one of these would just be insanity.
The T1 isn't necessarily a bad design though, as long as you can combat the wheel slip. It's got the speed potential of a 4-4-2, with the power of a 4-8-4.
@@nicholmansgarage3501 I just thought you meant the T1 was insanity too. Easy mistake to make as some people do indeed think it's insane. But yeah, the Triplex is an entirely different breed. Would be fun though, and if I had my own locomotive works, I'd be building all sorts of wacky designs, just because.
@@mattevans4377 i would be too! The strange and unusual stuff is far and away the most fun, in my opinion. I'd love to see some of ths stuff that never got preserved (cough cough B&O EM1 cough). Although that engine isn't necessarily odd, just a sad story
@@mattevans4377 If I had my own locomotive works I'd want to try and build a hydrogen burning steam locomotive. But yeah if money isn't a factor it would be fun to build all sorts of dumb experimental stuff. One of my other favorites would be a rear engined front wheel drive car.
Given that the Virginian's XA was successfully converted into 2 long-lived conventional locomotives, I wonder if the designers had made provision for such a conversion from the ground up, in case the triplex form didn't work out (which they might well have suspected, but had to deliver it anyway for the pointy-haired boss).
There are two significant errors in your opening introduction. The Union Pacific 4-8-8-4 "Big Boy's" only independently swiveling bogey was the forward one. The second set of drivers were permanently aligned with the boiler's central axis and did not swivel independently of the locomotive's frame. Secondly, the Big Boy's two sets of eight drivers were powered by just two high pressure steam cylinders per bogey, not three as stated in your introduction. UP had some classes of non-articulated 3-cylinder compound locomotives, notably the 4-12-2 "9000 Class" solid wheelbase engines, which represented the only use of this wheel arrangement in North America.
The Virginian Railroad had massive 2-10-10-2s that had the biggest diameter boiler used in the US. I have read that they could maintain there steam pressure will pushing heavy trains.
The first one built for the Virginian also suffered a boiler explosion in early 1941 (not sure if it was April of January because I didn't if the date was showing April 1st or January 4th because it could've been a British or American date), it's sad that we never got any preserved as the last AE (Virginian 2-10-10-2) to operate in revenue service was scrapped in 1949 (quite impressive for locomotives built in 1918 might I say)
The Triplex locomotives were compound engines. High pressure steam entered the center set of cylinders and the exhaust from these cylinders was split between the front and rear cylinders. Exhaust from the front cylinders went up through the stack. The exhaust from the rear cylinders went though a feedwater heater and then to atmosphere via a large pipe at the back of the "tender".
At the time of the Triplexes, the standard freight car was only 36 feet long, not 50 feet. It was also lighter than a modern freight car, and had a composite wood and steel frames.
Banking locomotives in the United States are referred to as 'helpers'. An American would not recognize the term 'banking'. They would assume that somehow the engine had accounts at a bank.
It was a good idea in theory but they could only do about 8MPH without running out of steam because the boiler we just not big enough to feed all those cylinders.
Makes me wonder wether with an admiralty pattern 3 drum boiler and running on oil or propane, with all the cylinder exhausts plumbed in for assisted draught through the boiler, or even with a condesor setup to save water and electric forced draught implemented, wether it would have been sufficiently efficient to have been doing long haul stuff at a higher speed
the boiler was sufficient in size and draft ,it was the mechanical stoker that was the problem, a major flaw of all mechanical stokers is their uneven distribution and incomplete coverage of grate thus limiting the fire
The funny thing is even though the Triplexes were a failure, the PRR still built the T1, S1 and Q1 - Q2 engines. Which even though had some success they were still a little extreme, and had similar problems to their predecessors.
Those were not articulating or mallet engines, however. All of those 'duplex' engines built by PRR were ridged framed, meaning separate sets of driving wheels and cylinders but mounted the same frame with no freedom to turn horizontally. Q2 6199 Actually boasted the most horsepower (not tractive effort) for any steam locomotive ever at 7,987HP.
@@theq4602 yes I am aware that these are equipped with Poppett Value Gear which doesn’t separate the frame from the boiler, however PRR took great inspiration from the Erie and Virginia when creating their Duplex locomotives (it is also easier to group them together for simplicity). Especially because the PRR believed that they could’ve fixed the design issues allowing larger locomotives to be able to show their true capabilities.
The T1 at least kinda showed that the concept was workable, but it had a lot of little technical details that had to be right that required precision which wasn't really cheap or as easily available back in the Steam era as it is today. afaik they'd mostly gotten the issues under control by the time they were starting to get obsolete. It'll be interesting to see PRR 5500 when it's finished.
@@TheDemocrab PRR actually sent some T1s to the C&O whose engineers were more experienced with multiple sets of driving wheels and largely didn't have any issues with them. PRR engineers were just too used to K4s for the most part and it basically ended up with what would happen if you gave someone who only drives a Camry a Lamborghini. Also just a heads up, 5550 is the one being built today, 5500 was one of the first T1s made and sadly not around anymore.
@@CarlosDeLosMuertes It's also worth noting that even the K4s were known to wheelslip even if it wasn't an "engine problem" - The K4 being underpowered for its typical use meant that crews were used to giving it the beans regularly, meanwhile the T1 was overpowered for its typical use if anything so it's little wonder really. Oops, thanks for catching that typo.
Happens to me regularly. I live near the end of a passing track and have to deal with trains slowing down going into and coming out of the hole on a regular basis.
The first set of cylinders(4 not 6) exhausted through the flues in the boiler. The rear drivers exhausted through it's own stack. Also Triplex referred to the fact that had 3 sets of drivers not 3 cylinders per driving wheels. 3 cylinder locos were tried here in the USA , but the hassle of serving the 3rd cylinder between the driving wheels was a head ache. Therefore most had the 3rd cylinder removed.
Another type of locomotive you can talk about are the Duplex style of engines that the Pennsylvania Railroad had. They're long rigid frame locomotives with 2 sets of driving wheels. The T1 tended to get a bad rap but honestly it's not really deserved. I'm sure you could give a fair short video on them and it be a lovely addition to your channel. Btw the Pennsylvania had 4 different duplexes in all. All with different wheel arrangements.
There’s so many duplexes to choose from though. There’s also the B&O’s N-1, which was had mirrored drivers, and then there’s countless duplexes in Europe that appeared to be Double Singles. Gaining the additional traction of a four-coupled machine, while retaining the “frictionless” nature of the Single
@@russellgxy2905 Well I figure it' would be easy enough to do a "reader's digest" style video on all the Duplexes that Pennsy owned. Yes theB&O did own one so that could be mentioned as well. Obviously there are plenty of videos out there on them already but i think it be a great addition to his channel anyway.
@@victoriacyunczyk Yeah I heard about that, some people say that's not true but you never know who was behind the throttle and honestly in those days one person says something and it spreads like wildfire and it just becomes facts. I believe that it is true and that the T1 reputation is over exaggerated to some degree. Did it have issues yes but are they as bad as people claim I doubt that but hey thays just how i see it.
Please do the Soviet П38 Паровоз ("P38 Parovoz" (which is "P38 steam locomotive")! They were a 2-8-8-4, and as far as I can tell, while 4 were ordered, I'm not sure if all 4 were eventually built, though there are no surviving examples. It's smaller sibling the П36, a 4-8-4 does have many working examples still today. There's not many RU-vid videos on the 38, and part of me wants to design a 5in gauge model as part of a really long term project. Thanks!
I think 2 sets of driving wheels (Like BigBoy & a Virginian Railway Class AG) should be the limit of a steam locomotives. It's like the old saying: "Bigger isn't always better".
In the end, the low top speed of these locomotives quickly doomed their usefulness. At least the Alco "Big Boys" could actually run at a decently high top speed.
I was about to say "But that's a tender engine!" But ended up eating my words when I saw there's another driving wheels on the coal bunker. Very absurd loco indeed
Well tie me to a chair and stick it to a ceiling, I did not see that coming. I've only ever heard of the triplex, but not the quadruplex or the quintuplex And then there was that last one which I'm not going to even try to pronounce
Make an engine that can pull 6 miles of cars. Siding and yards in the US have problems handling any train over 2 miles, which is taken from the union representative to the Union Pacific this year when explaining why traffic on the railroad was backing up.
I read from these Triplex Engines in a german book of railway engineering of the year of 1918, when a few german (prussian) railway engineers reported about of those locos. All three Triplexes had been owned by Baldwin but never had been bought from the ERIE RR where it had been tested and had showed that the too small firebox could not produce enough steam pressure to operate those engines effeciency enough. The exhaust of the front and rear Zylinders went into thr larger middle zylinders and used the steam expansion to drive all zylinders. The exhaust of the middle zylinders had been tiled also from one side to the front smokestack and from the otherside to the back smoke stack after heating the water inside the tender. One Engine had been sold to the Virginian Railways at Norfolk, Virginia where it had been built a little bit longer because of a much bigger firebox for burning virginian anthrazite coal, what brought more better results than burning the pennsylvania coal of what the ERIE RR wanted to haul to Buffalo or other Harbours at the great Lakes. At the ERIE RR those three Engines did shunting the coaltrains, theit max speed was around 25 mph as empty engine and more less than that with additional cars behind it. The Virginian #700 was much more efficient running by much higher speeds of up to 40 mph, the plan use it as pusher engine had been giving up very early, the loco could run ahead middle long standard trains but was too expensive in operation, so it was giving back to Baldwin in thr 1920's like I read from other railway engineering books of the 1920's. The problem were the tracks and the loco weight of metric tons per axle. The higher the loco weights the more bigger the tons per axle. Thr more expensive are the rails, what could carry those heavy engines.
Heavy pigeon chested was used So the blackbird could use white paint on the painting on both wings as a front so the black crow behind it and then use it as cover for 3 9
A super video. A minor thing though, the articulated locomotives have a + between the articulation, such as VGN 2-8+8+8-4 or the UP 4-8+8-4 Big Boy. Ridgid frame locomotives like the Pennsylvania Q1 4-6-4-4 did not have a + because they were not articulated, and technically, they would be tender back also, so it's actually a VGN 2-8+8+8-4TB, designating that the locomotive carries its fuel and water on the locomotive frame. 💙 T.E.N.
P.S. To the comments people, there were very few three cylinder locomotives in America, with a nice list of them somewhere in the comments below, and no articulated steam locomotive produced in America has three cylinder power, mostly due to maintenance issues and costs, but there are some in other countries. 💙 T.E.N.
And the quadruplex locomotive could've worked have the front and rear bogies been articulated, and perhaps shortening it to a 2-6-6-6-6-2 wheel arrangement.
The Erie triplex locomotives weren’t absurd they were just another power classification engine and it was an attempt to see if an engine class could haul more freight than the big boys because if they did become successful, then the Triplex class would’ve been the last of the Giants and not the big boys.
*Love the "Banjo Kazooie" music in the background of this video.* Such a great game that was released on the N64 back in the day. The Big Boy however is the true largest steam locomotive that was actually ever built and put into operation. Yes, there are some very worthy contenders for the largest title like the Yellowstone's and the Allegheny locomotives. (All U.S.-built locomotives still) But when you take all the different ways to measure a locomotive and average those numbers out, the Big Boy is the largest locomotive. Again the runner-ups in a neck and neck race are the Yellowstone's and Allegany. The XA Triplex and Erie class are also then good contenders in some measurements. But in the end, U.S. locomotives dominate in this whole class of the world's largest anyways. The top 10 contenders are all U.S.-built locomotives. But as mentioned in the video, the U.S. has the heaviest loading gauge. So hence the least amount of restrictions for weight and overall size.
@@sambrown6426 Yeah, but these locomotives are still considerably smaller than U.S. steam locomotives. And the Russian locomotive couldn't even be used at all and was promptly scrapped. It was never actually used by the railroad except once as a publicity stunt. But it never pulled any Revenue Freight because it was too strong for the couplers of the time and too heavy for the tracks in Russia. The British locomotive is just a small locomotive centered between a water and oil tank bogey's. So these locomotives are quite a bit smaller than their American counterparts and don't even make the top 10. But keep in mind that the US also has the world's heaviest loading gauge. So that's why the U.S. can build such incredibly huge massive locomotives. 🙂
The Big Boys did not use three cylinders per bogie, it used the conventional two! The three-cylinder arrangement uses the Gresley Conjugated Valvetrain where the timing for the center cylinder is derived from the valve positions of the outer-two. The design reduced wear on the tracks and provided a more uniform application of torque, hence reducing wheel-slip at slow speed. The major drawback was accessibility issues to the center cylinder for maintainance and the fact that its main-rod operated at a greater angle hence greater wear/stress to its bearings and sliding surfaces An interesting fact: When the Mallard set the record for the fastest steam engine ever it "threw out" its center rod and had to limp home.