In the 1890s, the Gotthard Railway in Switzerland operated the first Mallet locomotives. They were compound articulated locomotives developed by, and named for, Swiss engineer Anatole Mallet. The Mallet was a slow-speed engine intended for use on mountain grades or on heavy drag freights. Its design, with the articulated frame, permitted a powerful locomotive to negotiate the often sinuous track found in mountainous territory.
A Mallet locomotive has two engines, which are independently mounted on an articulated frame. A high-pressure engine is located at the rear. Steam exhausted from it is conveyed forward to a low-pressure engine that is on the articulating part of the frame at the front of the locomotive. Because exhausted steam from the rear engine has been partially expanded (and has a greater volume than high-pressure steam), the low-pressure cylinders of the front engine need to be much larger than those of the rear high-pressure engine. The boiler is mounted so that roughly an equal amount of the locomotive's weight is supported by each engine. This gives each about the same adhesion, and under normal operating conditions, the same power.
The Mallet offered some big productivity improvements. The widespread application of air brakes in the latter part of the 19th century meant that railroads could safely run longer and heavier trains. A single Mallet could handle these bigger trains in mountainous terrain, thus eliminating the expense of doubleheading. An 0-6-6-0 produced 50 percent more tractive effort than a 2-8-0, the favorite freight engine of the day, and only needed one crew.
Many 2-6-6-2s were built in the first decades of the 20th century, with successive locomotives incorporating various design improvements. After 1910, superheating became standard. The firebox was moved behind the rear driving wheels and supported by an outside bearing radial trailer truck. Combustion chambers were added. The locomotive grew in size. The 2-6-6-2 was a drag freight engine, not capable of speeds above 20 or 25 mph. As a result, its application was limited to low-speed, heavy-hauling tasks.
Overall, about 1,300 2-6-6-2 locomotives were built for use in North America.
One place where the 2-6-6-2 proved popular was in the woods. A number of western logging companies used both tender and tank versions to power log trains headed for its mills. These oil-burning engines were much smaller than their mainline cousins but were ideal timber haulers. Their high adhesion and articulated frames gave them the ability to handle sizeable trains over curving and lightly built track. Many of those locomotives lasted well into the diesel era.
California Western Railroad also had a 2-6-6-2. She was known as the “Super Skunk”. She was built by: Baldwin Locomotive Works in June 1937. She was a BLW Class 16 30/50 1/4DD8, builder's No. 62064. She was a 2-6-6-2T split-saddletank engine with two water tanks straddling the boiler, and oil bunker at the rear of its cab.
When #46 was new she was the 2nd-last logging Mallet and last steam engine delivered new to Weyerhaeuser Timber Company. She first worked at Camp McDonald, WA as No. 110 (2nd), and used in Longview area logging operations. Weyerhaeuser replaced its rail spurs with truck roads in 1946. WT No.110 was then used between central loading points and a sawmill. In 1954 she was bought by Rayonier,Inc., numbered No. 111, and used on Rayonier's ex-Polson Logging
Grays Harbor County, WA lines on the New London (Hoquiam)-Railroad Camp 3 branch (all-steam until May 1967 abandonment, when she pulled the last train) and then as a standby on the New London-Railroad Camp-Crane Creek mainline until all steam operations ended later in 1967. A slopeback tender of unknown origin from Polson (ex-A&NM) No. 18 was added.
In 1968, she was bought by Georgia-Pacific Corporation's California Western Railroad, for use on Fort Bragg-Willits Super Skunk trains. Rebuilt as CWR No. 46 at the Fort Bragg shops in 1968-70, her saddle tanks and fuel bunker were removed, making her a 2-6-6-2 without the "T". Ballast was added under the running boards to restore traction, and also new cab seats, spark arrester, and an ex-SP whistle. She was painted vermilion, red, gold, and black, with a skunk cartoon on the rebuilt tender's now-rectangular sides. CWR No. 46 began passenger service on August 20, 1970, pulling ex-Erie Stillwell coaches and ex-SP commuter coaches. She ceased steam service in 1981.
In July 1984 Georgia-Pacific (the successor owner of the Union Lumber Company which in turn owned the Skunk line) donated CWR No. 46 to the Pacific Southwest Railway Museum Association (PSRMA) in San Diego. In May 1986, she was moved free on her own wheels by the CWR to Willits and SP's NWP to Santa Rosa, where she was disassembled and loaded on two flatcars. One carried the tender and front chassis, the other the rest of the locomotive. She was taken free by SP, Santa Fe, and SD&IV to San Ysidro, unloaded and reassembled. She went to Campo in reverse on February 28, 1987 and is now on display in the museum yards She will be restored to operating condition when funds become available.
2-6-6-2 G Scale Model Locos
In piston engine locos there are few G scale models that are prototypical of the real thing that ran along the Mendocino Coast. In geared locos, Heisler, Climax and Shay there is a good supply of G Scale models that are very good “imitations” of the real thing.
Club member Basil Casabona has one 2-6-6-2 loco which is close to the real thing. Compare the photos below of Basil’s 2-6-6-2 “in action” to those above to see how “close” the model and the “real thing” are.