Steam & Excursion > "Erie Triplex" (2-8-8-8-2)

Do you think this locomotive has enough driving wheels ??

Erie Railroad # 2603 ("The Matt Shay")
A 2-8-8-8-2 Steam Locomotive, built by Baldwin in 1914..

Date of photo: unknown..
Photo courtesy of "Marvin Maynard Collection"..

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Plenty of drivers...not enough boiler. I read a quote that the coolest place to be on a hot summer day was against the backhead of one of these boilers.

OT

KeyRouteKen Wrote:
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> Do you think this locomotive has enough driving
> wheels ??
>
> Erie Railroad # 2603 ("The Matt Shay")
> A 2-8-8-8-2 Steam Locomotive, built by Baldwin in
> 1914..
>
> Date of photo: unknown..
> Photo courtesy of "Marvin Maynard Collection"..

Articulated or not, this beast must have been murder on curved rail!

Why would it be any worse than any other eight-coupled engine?

This loco was a poor steamer. Needed 2 boilers really....

CPRR Wrote:
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> This loco was a poor steamer. Needed 2 boilers
> really....

Not 2 boilers, but maybe two fireboxes.

That machine was doomed before it left the drawing board. I guess it gives precedence and justification to the DHS's policies.

Anyway, 2-8-8-0's were notoriously poor steamers to begin with (though UP and, particularly, GN had reasonable success), and even though Matt had 90 feet of grate, an arch, and a substantial combustion chamber, there was just no way to build a decent fire above that 2nd set of drivers. The inadequate firebox, combined with the fact that 1/2 of the exhaust steam was exhausted from the tender rather than assisting the draft thru the front end, meant that Matt couldn't possibly generate enough steam to power two cylinders.

Two?

Yeah, two. Only the center cylinders received steam directly from the boiler. The exhaust from the right went to the front two cylinders and from the left went to the rear engine.

The more one thinks about this engine, the more reasons one can see why it didn't meet the designers expectations.

Curiously, someone must have told the Virginian that a 4 wheel trailer truck would improve combustion, so they stuck one under the tender on their copies. That didn't help either!

I presume there was also a power imbalance since the middle unit was HP and sent LP steam to both front and rear units. On a conventional Mallet the front unit is LP and has roughly double diameter cyclinders. Both front and rear should produce similar amounts of power. Here the cylinders are all the same size but there are 4 LP cylinders. That works in term of having twice the LP cylinder capacity as HP but it seems to me that would have the front and rear driving units putting out half the power of the middle unit. And rear unit exhaust steam going up a small stack at the rear of the tender and not aiding in drafting the boiler doesn't help matters.

I've often wondered, looking at a UP 4000, whether the weight carried by the trailing truck is wasted since the firebox is high enough to be over the rear drivers anyway so the usual idea of a trailing truck carrying weight of a firebox that drops down behind the drivers is not the case here. Making the driving units ten-coupled engines wouldn't lend itself to a fast flexible locomotive so maybe the next bigger thing beyond a Big Boy would have been a 4-6-6-6-0. Unlike the Triplex shown above this would have been a simple articulated, not compound, and the tender, with its varying weight, would have nothing to do with it. All three driving units would be on the locomotive alone with the rear driving unit mostly under the firebox.

filmteknik Wrote:
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> <snip> On a conventional Mallet
> the front unit is LP and has roughly double
> diameter cyclinders.

Area, not diameter.

The really big improvement on Big Boy's and Yellowstones was the length of firebox that the 4 wheel truck allowed. Matt Shay had 90 square feet of grate, a huge improvement over the 60 square feet of a Mikado or Pacific of the period. But, Big Boy had 150, and NP's 2-8-8-4's had 183 - more than twice the triplex's! Those huge fireboxes could generate enough heat to keep the rest of the kettle hot, even though they were shallow.

I believe later on Erie used the engine from under the tender and put a boiler on it, making a new 2-8-0. Apparently it also was a poor locomotive and some hoghead was quoted as saying, "Looks like we just took a ride on the anal apperature of the Matt Shay." - Tony J.

The Virginian Triplex, No. 700, was turned into two locomotives in 1921, a Mikado numbered 410 and a 2-8-8-0 numbered 610, which became a 2-8-8-2 in 1942.

MTMEngineer Wrote:
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> > Big Boy had 150, and NP's 2-8-8-4's had 183 - more
> than twice the triplex's! Those huge fireboxes
> could generate enough heat to keep the rest of the
> kettle hot, even though they were shallow.


I have it my head that the late UP 4-8-4s, such as the 844, had 140 sq ft of grates. Is that so? If true, that makes Big Boy's 150 seem a bit small.

Doug Wrote:
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>
> I have it my head that the late UP 4-8-4s, such as
> the 844, had 140 sq ft of grates. Is that so? If
> true, that makes Big Boy's 150 seem a bit small.
>
>
I can't put my hands on the 844 specs, but the 140 figure is a bit overstated for a 4-8-4.

UP 820-834 series (previous class of UP 4-8-4's) had 100.2 sq ft.
ACL class R-1, 97.75
Q O-5, 106.5
CN U-2f, 84.3
GT U-4b, 73.7
CP K-1a, 93.5
C&O J-3, 100
CNW H, 100
Milw S-2, 106
CRI&P 88.3 (Milw 261 is a copy of this engine)
Lackawanna Q-4a, 88.2
DRGW M-68, 106
GN S-1, 102
GN S-2, 97.7
MP 2101-2105, 88.3
LV T-1, 88
LV T-2, 88.3
LV T-3, 96.5
SOO O-20, 88.3
NP A-3, 115 (SP&S 700 is a copy of this engine. NP's A-3 to A-5 were the largest fireboxes on 4-8-4's)
RF&P 601-606, 86.5
TP&W, 77.3
Wab O-1, 96.2

U.P. 844 has the same 100.2 sq. ft. grate area as the previous group. BTW, I believe the N.P. later blocked off part of the forward section of the Yellowstone's huge grate, making the effective area about the same size as that of the Big Boy.

Said elsewhere: The really big improvement on Big Boy's and Yellowstones was the length of firebox that the 4 wheel truck allowed. Matt Shay had 90 square feet of grate, a huge improvement over the 60 square feet of a Mikado or Pacific of the period. But, Big Boy had 150, and NP's 2-8-8-4's had 183 - more than twice the triplex's! Those huge fireboxes could generate enough heat to keep the rest of the kettle hot, even though they were shallow.


The NP's Z-5s burned Rosebud coal, with much lower heating value than the coal used in other Yellowstone-type locomotives. They simply needed more space to allow enough burning coal to create steam. This limited their HP to about 5000, compared to about 6000 hp for the others, which included the Missabe's, B&O's (yeah, I know, this IS the Western Board!) and SP's Cab Forward (AC-9s). NP eventually had to block off some of the area at the front of the firebox (stoker couldn't get the coal there?) of the Zs.