CB&Q Mallets: The Biggest Engines in the Hills

Black Hills Central #110.  Keystone, SD.  James Willmus, 2012

The Chicago Burlington and Quincy Railroad built a rail line through the heart of the Black Hills known as the "High Line". The branch, which would one day become the George S Mickelson Trail had steep grades and sharp curves, but at the turn of the Twentieth Century there was a need to haul freight on the line to and from Deadwood. Large, solid frame engines couldn't make the turns and big drivers wouldn't do well on the grades, so a new engine was needed for the fleet.


Fortunately, other railroads had the solution, articulated locomotives. Instead of one long set of driving wheels, the drivers were divided into two sets of bogies with their own separate valve systems. The most common arrangement of articulated locomotives was the compound mallet. This type of engine used the steam twice with high-pressure cylinders in the back and low pressure cylinders in the front. While traveling between the driver sets, the steam was reheated. The supposed benefit was that these engines had increased tractive effort, a long wheel base that could negotiate tight curves, and used steam as efficiently as possible. Compared to a standard engine, mallets were slow, thirsty beasts and were not useful on flat land. However, in the Black Hills these engines were in their element.


While today the Black Hills still has mallets, they are not historically accurate for the area.  #110 and #108 came from Weyerhaeuser in the Northwest United States.  Both the current and past engines had similarities though.  Both were 2-6-6-2 type engines and both came from Baldwin.

The CB&Q had three classes of mallets:

• T-1
• T-1a
• T-2

The T-1's were the first type to be built and were identical to the Great Northern L class 2-6-6-2's from 1906.  These three engines, numbered 4000-4002, were originally built for the GN as the second batch of L-1's, but the CBQ ended up buying three of the units while the GN purchased the rest.

The relative success of the T-1's prompted the CB&Q to order a batch of their own which would become the T-1a class.  Similar to the T-1's, the T-1a's were slightly smaller, but heavier.  These five engines were numbered 4003-4007 and were delivered in 1909.

Both the T-1 and the T-1a's were converted into 0-8-0 switchers between 1927 and 1929, but remained in service until at least 1948. However, the T-1's were moved to Galensburg, Illinois within a couple of years of the T-1a's being in service in the Black Hills.

The last class of mallet known to operate in the CB&Q Deadwood branch was the T-2's.  10 of these units were ordered from Baldwin.  They were bigger, longer, and could pull more weight. They were delivered in 1910 and numbered 4100-4109.

Finding information and public domain photos of these engines are difficult.  I will add photos as I get permissions, but I have found a couple of documents that are valuable to this post.

The University of Illinois has in their catalog digitized copies of the American Engineer and Railroad Journal, Volume 80, October 1906 and Volume 84, May 1910 have locomotive diagrams featuring the GN Class L-1's and the CB&Q Class T-2's respectively.

Here are links to these journals via hathitrust.org:

GN Class L-1's

https://babel.hathitrust.org/cgi/pt?id=uiuo.ark:/13960/t5cc1q03w;view=2up;seq=477;size=200

Article is on pages 371-376 of the Journal (Pages 477-484 on the digitized document).

CBQ Class T-2's

https://babel.hathitrust.org/cgi/pt?id=uiuo.ark:/13960/t2794zp53;view=1up;seq=281;size=150

Article is on pages 171-174 of the Journal (Pages 279-284 of the digitized document).

I'd like to use this info to build models of these engines in the future.