2-8-8-8-2

type.

Other equivalent classifications are:

UIC classification: 1DDD1 (also known as German classification and Italian classification)

French classification: 140+040+041

Turkish classification: 45+44+45

Swiss classification: 4/5+4/4+4/5

The equivalent UIC classification is to be refined to (1'D)D(D1') for these Triplexes.

Baldwin built the only three examples of the type for the Erie Railroad between 1914 and 1916.Harvnb|Westing|1966|p=124-125.] The first was named "Matt H. Shay", after a beloved employee of that road. All three, as well as the lone 2-8-8-8-4 and several Virginian Railway electrics, shared the nickname "Triplex" because of their three sets of drivers. (Compare Duplexes, which had two sets.)

Overview of Triplex engineering

The Triplexes' purpose was pusher service (high tractive effort, low speed, short distances).

The center set of cylinders received high-pressure steam. The exhaust from these was fed to the two other sets of cylinders, which were valved for low pressure. 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. 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 Triplexes produced huge amounts of tractive effort (TE) that may have been the highest of any steam locomotives before or since. [Westing 1966:124-125 gives a figure of convert|160000|lbf|kN|abbrev=on in compound mode and seems to indicate that it was the largest TE for any locomotive up to the time (1914-1916). See the Tractive effort article for other TE figures.] The Triplexes could also be considered the largest tank locomotives ever built since the tender had driving wheels as well and thus contributed to traction. The problem of variable adhesion on the tender unit was not a serious one, since helper locomotives had frequent opportunities to take on additional fuel and water.

References

Bibliography

* .

External links

* [http://www.toytrains1.com/triplex.htm Web Site of ToyTrains1 2-8-8-8-2 Triplex Steam Locomotives]