Barduck

Virginian 2-8-8-8-4 Triplex (Version 4)

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Only one 2-8-8-8-4T was ever built, a Mallet-type for the Virginian Railway in 1916. This is the one in the above photo, it is also the one that you are about to build using these instructions. Built by Baldwin Locomotive Works, it became the only example of their class Xa, so named due to the experimental nature of the locomotive. Like the same railroad’s large articulated electrics and the Erie Railroad 2-8-8-8-2s, it was nicknamed “Triplex”.

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The purpose of the Xa was to push heavy trains over steep inclines, requiring high tractive effort, but low speed, over short distances. The Xa worked on a difficult 14-mile section from Elmore to Clark’s Gap.

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The Xa’s center set of cylinders received high-pressure steam, and the exhaust from these was fed to the two other sets of cylinders, which were valved for low pressure.The right cylinder exhausted into the front set of low pressure cylinders, and the left into the rear set; this is also why the high pressure cylinders have the same diameter as the low pressure ones, whereas most mallet locomotives have much smaller high pressure cylinders. The front set exhausted through the smokebox and the rear set exhausted first through a feedwater heater in the tender and then to the open air through a large pipe, which can be seen in the photo. Since only half of the exhaust steam exited through the smokebox, firebox draft (and thus boiler heating) was poor.

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Although the boiler was large (in line with contemporary two-cylinder and four-cylinder practice), six large cylinders demanded more steam than even such a boiler could supply. With all six cylinders operating at their full pressure (which could not be sustained for very long), the Xa produced huge amounts of tractive effort that may have been the highest of any steam locomotive before or since (160,000 pounds-force in compound mode, which was the largest tractive effort for any locomotive up to the time,1914-1916).The Xa is also considered the largest tank engine ever built since the tender had driving wheels as well and thus contributed to traction. The problem of variable adhesion on the Xa’s tender unit was not a serious one, since pusher locomotives had frequent opportunities to take on additional fuel and water.

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The Xa was unable to sustain a speed greater than five miles an hour, since the six cylinders could easily consume more steam
than the boiler could produce. The tender had a four-wheel truck at the rear to help guide the locomotive into curves when
drifting back downhill after pushing a train over the hill.

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This MOC has around 2800 parts in her (and about 80 3D printed parts). She runs on PU, 1 battery, 2 Large motors. Decals made by OKBrickWorks.com

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Even as large as she is, she still manages to take R40 turns

https://flic.kr/p/2kJu33v

and switches:

 

https://flic.kr/p/2kJq1K4

She can even take light graded slopes (1 plate/straight increase)

https://flic.kr/p/2kMA1um

Instructions available on Rebrickable

Edited by Barduck
typo

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Is that a locomotive in the video, or a very large caterpillar?

This model is stupendous in just about every way - size, accuracy, detail and ability to negotiate standard TLG track. The chrome parts and custom decals top it all of nicely. I think the only possible improvement could be working lighting - fantastic work.

How long did she take to design and build?

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3 hours ago, ColletArrow said:

How long did she take to design and build?

Well, it is already V4. V1 got scrapped, V2 got burned to a crisp. V3, of which I have only done renders took about 2-2,5 months to redesign starting from V2. I pushed her a bit to enter the Brick Train Awards. But instead of building her, I finetuned her, extra hatches on the cabin roof, shortened her and the tender a bit, lowered the cabin roof, etc etc. And thus V4 was born. I recon, if I'd had to start from scratch she would have taken the better part of 6 months to design. Once the parts were ordered and printed (the valvegear is homemade, from design to printing) she took about 3 days to build at around 4 hours a day. That might seem long but I didn't want to push her and make building mistakes. And test while building (and even change the design a bit at some places to add more rigidity or change how something was connected. At the end testfase, where I was testing to see if she'd take R40 I made another change to enable her to do just that. All it took was changing the set up of the wheels on the second truck from F-B-F-B to B-F-B-F. To enable her to take R40 switches all I had to do was change the beam connecting the second (last loco truck) and the third (tender) truck from 9 long to 11 long with pins at hole 1 and 10. Even though she can take R40 (and actually I designed her with that in mind), she'll look a hell of a lot better on R104 curves and switches

Edited by Barduck
typo

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3 hours ago, Barduck said:

Well, it is already V4

This is a wonderful design story! A strong demonstration of dedication. Of ingenuity. Of superb building skills. Of patience. Of so many more things that come to mind.

As others have said: Beyond belief. Beyond anything, I can imagine. And yet: Reality.

Wow.

I am speechless.

Congratulations, @Barduck

This is fantastic. Thank you very much for sharing!!!

Best wishes and have endless hours of fun!

Thorsten

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Hats off to you, Barduck,

Seeing this, I think I need a moment just to lift my jaw off the floor!

Love all the incredible details, especially all that piping, plumbing and undercarriage. This is a work of art, thank you!

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8 hours ago, brick-builds said:

Wow, very good work. Do you have a video of the train?

there's 3 linked in the topic

 

16 minutes ago, High_Admiral said:

You've outdone yourself once again, great work on the Triplex!

thanks, she's a complicated but fun build

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As others have said, this is simply amazing. The rods and valve gear assemblies are fascinating to watch. So much detail. Really well done!

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That monster is insane! Amazing work, and unbelievable that it can do R40, so equally amazing engineering. Now you just need 100 coal cars to shove up the grade (grin)

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On 3/31/2021 at 4:31 PM, zephyr1934 said:

That monster is insane! Amazing work, and unbelievable that it can do R40, so equally amazing engineering. Now you just need 100 coal cars to shove up the grade (grin)

I'm afraid 100 coal cars are a bit above budget. Could you spot the differences with V3 (and V2)?

 

On 3/31/2021 at 9:35 PM, Dr Snotson said:

This is why we do what we do... that`s it - that`s all! Awesome and inspiring piece of art!

not inspiring enough for myself, don't think I'll be tangling another steamer this year, this one was already enough

 

Everybody else that commented (can't be quoting them all): thank you for your kind words on how much you like her, now of you go to Rebrickable and buy those plans :devil:

Edited by Barduck

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