Moguls, The 2-6-0 Wheel Arrangement

The 2-6-0 wheel arrangement developed from the 0-6-0 wheel arrangement but was initially rather unsuccessful due to its rigid front pilot truck that could not freely swivel to better negotiate the curves and poor track conditions of the time. Due to this problem, from the time the Mogul was developed, as early as the early 1850s, through the early 1860s few were sold (about 30) and railroads found them to be little better (in terms of tractive effort) than the trusty American Type.

The 4-4-0 American Type can be given overwhelming credit, more than any other steam locomotive design before or since its development, for helping the United States flourish beginning in the latter half of the 19th century. After their debut and minor refinements the 4-4-0 wheel arrangement quickly proved its superior ability over all other types of its day and by the 1870s well over three-quarters of all steam locomotives operating in the country at that time were American Types! While the railroads themselves built our great nation into what it has become today, their initial workhorse in achieving that task was the 4-4-0 wheel arrangement.

The success of the 2-6-0 wheel arrangement came with the addition of the free swiveling “bogie” front truck originally patented by Levi Bissell in the late 1850s. After this pilot truck was attached on the Mogul it greatly increased the locomotive’s abilities to negotiate curves and the rough track conditions of the day. Also, due to the Mogul’s greater adhesion over an American Type and lower cost compared to a Ten-wheeler, with its design flaw corrected it sold quite well, particularly on short lines where money was not only tighter but also because the 2-6-0 could travel on light track due to its lightweight.

While the Mogul performed about every task imaginable on short lines, its use on Class Is was a bit more specialized. Here, the Class Is realized that the 2-6-0’s best advantage was its ability to haul medium-sized trains over relatively even track saving the heavier movements for trains like the Ten-wheeler and Consolidations.

The Consolidation Type, which had bumped Ten-wheelers from main line freight trains on most Class I systems of the day, was a highly successful steam locomotive design of the latter half of the 19th century that would eventually replace the American Type, 4-4-0 wheel arrangement. The new Consolidation, a 2-8-0 wheel arrangement, allowed for more tractive effort with two additional driving axles and thus could haul much heavier trains than the American design.

The 2-8-0 design was a significant technological leap from the American, 4-4-0 wheel arrangement. The Consolidation, with its two extra driving axles and front pilot truck could not only pull trains that were twice as heavy but also run at speeds fast enough to be used in any type of passenger service. For instances, railroads such as the Baltimore & Ohio, Pennsylvania, and others, which operated in mountainous territory found that the Consolidation Type performed exemplary over stiff grades.

The 2-6-0 wheel arrangement would continue to be built through the early 20th century (with a final total of over 11,000 built when production ended on the wheel arrangement) and interestingly lasted on Class I rosters essentially up until the end of the steam era performing light duty and yard work! Today, like Consolidations and Ten-wheelers, numerous Moguls have been preserved across the country with some still in operating condition such as famed #89 on the Strasburg Railroad, an ex-Canadian National Mogul. The little steam locomotive is used in regular service throughout the operating season so you have plenty of opportunities to see it in action or ride behind it!

For more information on Moguls consider one (or both) of the books below. Guide to North American Steam Locomotives by author George Drury includes nearly 500 pages of information on virtually all of the steam locomotive wheel arrangements and designs (including streamlined steamers) ever developed. The book is a great resource on steam locomotives and a fine reference tool; you should find it very useful.

Also, consider the book American Steam Locomotives from author Brian Solomon. While this publication does not include quite as much technical data as Guide to North American Steam Locomotives it is still a very good resource with lots of information and best of all, is loaded with photographs!