View source for 4-8-8-2

{{Short description|Articulated locomotive wheel arrangement}}
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[[File:Southern Pacific 4294, a cab-forward steam locomotive.jpg|thumb|300px|Southern Pacific 4294, preserved at the [[California State Railroad Museum]] in Sacramento, California]]
[[File:WheelArrangement 4-8-8-2.svg|thumb|300px|right|4-8-8-2 wheel arrangement]]
Under the [[Whyte notation]] for the classification of [[steam locomotive]]s, a '''4-8-8-2''' is a locomotive with four [[leading wheel]]s, two sets of eight [[driving wheel]]s, and a two-wheel [[trailing truck]]. 

Other equivalent classifications are:<br>
[[UIC classification]]: '''2DD1''' (also known as German classification and [[Italian classification]])<br>
[[French classification]]: '''240+041'''<br>
[[Turkish classification]]: '''46+45'''<br>
[[Swiss classification]]: '''4/6+4/5'''

The equivalent [[UIC classification]] is refined to '''(2'D)D1'''' for simple articulated locomotives.

A locomotive of that length must be an [[articulated locomotive]]; meaning all have a joint between the first and second groups of driving wheels.  All examples of this type are [[cab forward]]s.  Normally, the leading truck sits under the smokebox and the trailing truck under the firebox. On a cab-forward, the leading truck supports the firebox and the trailing truck and smokebox are at the rear next to the tender. A 4-8-8-2 is effectively a [[2-8-8-4]] that always runs in reverse.

== Southern Pacific ==
The [[Southern Pacific Railroad|Southern Pacific]] was the only railroad to operate engines of this wheel arrangement, all of which were built by the [[Baldwin Locomotive Works]]. A total of 195 were produced between 1928 and 1944 in eight batches. The later ones had cylinders 24 inches by 32 inches, drivers 63-1/2 inches and boiler pressures of 250 psi, giving a calculated tractive effort of 123,400 lb.<ref name=steamloco>{{cite web |url=https://www.steamlocomotive.com/locobase.php?country=USA&wheel=4-8-8-2&railroad=sp#344 |title=Southern Pacific 4-8-8-2 "Cab Forward" Locomotives in the USA |publisher=Steam locomotives dot com |access-date=6 March 2021}}</ref>

The locomotives were built as cab-forwards to protect engine crews from exhaust smoke and heat in the many tunnels and [[snow shed]]s that were part of their usual routes.<ref name=steamloco/> Although commonly called ''[[Mallet (locomotive)|Mallets]]'' these cab-forwards were built with simple expansion cylinders.  The name stuck because the original classes of Southern Pacific cab-forwards were built as compound Mallets, though these were eventually converted to simple expansion machines.<ref name=asme/>

[[Southern Pacific 4294]] was the only cab forward to be preserved after being withdrawn from service. It was donated to the City of [[Sacramento, California]] in 1958, but had to be moved due to freeway construction. It was given to the State of California and is on indoor static display at the [[California State Railroad Museum]] in Sacramento.<ref name=asme>{{Cite web|title=# 4294 Cab-In-Front Articulated Locomotive |url=https://www.asme.org/wwwasmeorg/media/resourcefiles/aboutasme/who%20we%20are/engineering%20history/landmarks/62-southern-pacific-4294-cab-in-front-steam-loco.pdf |date=May 7, 1981 |access-date=January 1, 2020}}</ref><ref>{{cite news |title=trucking business |url=https://rindx.com/trucking-business-plan/}}</ref>

==References==
{{Reflist}}

===General reference===
* {{cite book| last1=Diebert| first1=Timothy S.| last2=Strapac| first2=Joseph A.| name-list-style=amp| title=Southern Pacific Company Steam Locomotive Compendium| publisher=Shade Tree Books| year=1987| isbn=0-930742-12-5}}

==External links==
*[http://www.toytrains1.com/cabforward.htm Web Site of ToyTrains1 4-8-8-2 Cab Forward Steam Locomotives]
*[https://web.archive.org/web/20080420195854/http://www.steamlocomotive.com/cabforward/ Steam Locomotive.com's Southern Pacific Cab Forward article, including detailed specs.]

{{SP cab forward locomotives}}
{{SP AC class locomotives}}
{{Whyte types}}

[[Category:4-8-8-2 locomotives| ]]
[[Category:Whyte notation|88,4-8-8-2]]
[[Category:Simple articulated locomotives]]