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RattlerJones [2019-07-16 22:05:24 +0000 UTC]

The biggest steam locomotive ever built on the planet, even in the United States of America is a 4-8-8-4 articulated engine, famously known as the 'Big Boy'. 
It began in the late 1930's when the Union Pacific Railroad always used helper locomotives to move trains from Odgen to Wasatch in Utah. 
To simplify the move, the U.P. asked their "Department of Research and Mechanical Standards" to design a locomotive which could haul a 3,600 ton freight train over the 1.14% grade of the Wasatch Mountains without needing any helper. 
Though the designers determined that in order to pull a train which weighed about 3,600 tons, a tractive effort of 135,000 Ibs would be acquired. 
A factor of adhesion of 4.0 was also acquired, followed by a driving wheel weight at 540,000 Ibs. 
A axle loading of 67,500 Ibs each would require eight driving wheels or an x-8-8-x arrangement, thus having agreed upon the 4-8-8-4 design. 
Up next was the horsepower and the sizes of cylinders which were computed based on a boiler pressure at 300 psi. 
These 4-8-8-4's weren't figured to haul freight trains at speeds of 80 MPH, the DoRMS designed them for 80 MPH to have a sufficient factor or safety built into the design. 
What resulted is considered by many to be the most successful articulated steam locomotive ever built since 1941. 
At first, the 4-8-8-4's were to be named; the 'Wasatch' class, but a chalk-written note "Big Boy" was planted on one of the newly-built mallets, and the name stuck. 
By Sept. 5th, 1941 at 6 PM in Omaha, Nebraska, the firstly-built Big Boy no. 4000 was delivered. 
Twenty-five of these mammoth articulateds built by the American Locomotive Company were divided into two groups; twenty of them were called the "Class 1", numbering from 4000 to 4019, and finally five more in the 2nd group called the "Class 2" built in 1944, numbering from 4020 to 4024. 
By the eventual end of the steam era on the Union Pacific, one of the Big Boys hauled the last revenue freight train in July 1959. 
Most of the other Big Boys retired in 1961, followed by a last Big Boy retiring in July next year. 
By late September that same year after 1961, four-remaining Big Boys were in operation for the last time at Green River, Wyoming. 
Today only eight of the largest steam locomotives ever built remain, either in storage or on display around the United States. 
One is still owned by the Union Pacific, number 4006 while its brother locomotive number 4014 returns in full steam since 2019 after seven years of restoration. 
Now, the 4014 is today's the largest steam locomotive in America.

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steam-dieselpunkpunk [2019-07-16 09:02:45 +0000 UTC]

Saw him in my home town managed to get decent pictures and patted his front such power

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MILW-F6A [2019-07-16 01:52:52 +0000 UTC]

my cripes....

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jimmyhook19202122 [2019-07-16 00:05:12 +0000 UTC]

Man..... it's just amazing of how long a Big Boy really is when you get close to one

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