Big Boy Talk.

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Where everyone can talk about the Big Boy.


  1. EnginneerJoe's Avatar
    Baldwin’s Big Boy

    From the mid 1800’s through 1960’s there were three main locomotive manufacturers when it came down to steamies. Baldwin Locomotive Works, American Locomotive Company, and Lima Steam Foundry. They were called the “BIG THREE”. I would like to discuss the largest steam locomotive built by any of the “BIG THREE”, Baldwin’s Big Boy.

    From the early 1800’s until the 1960’sindustry leader Baldwin Steam Works designed and built some of the most iconic and technologically advanced steam engines of all time. Some of the most famous and memorable are the 4-4-0 Americans, 2-6-0 Moguls, 2-8-0 Consolidations, and 4-6-2 Pacifics. Some of their supreme advancements in steam technology were the small sized 2-8-2 Mikados and 2-4-2T/2-6-2T/ 2-2-2T tank-switch engines. Baldwin’s mid-size 4-8-2 Mountain was oneof the first designs converted to an oil burner. Larger designs such as the 4-6-4 Pacifics birthed the super engines such as steam turbine ‘Jawn Henry’Types. In the late 1880’s - 90’s trains crossing the mountains and vast reaches of the United States began to haul ever larger and larger consists of cars. The need for more pulling power prompted Baldwin to build the 4-8-4 Texas-1 then the 4-10-4 Texas-2 these failed to keep pace with growing consists weights after a time of success. Then Baldwin introduced the 2-4-4-2 articulated prototype, then the 4-4-6-4 Buster articulated Super-Steam Engines. The 2-8-8-4 Yellowstones and 2-6-6-6 Alleghenies conquered the mountains while the 4-6-6-4Challengers and 2-8-8-4 Lincolns set speed records. However an engine was needed that could both scale mountains and trod prairies with ease. Thus Baldwin built the monstrous 4-8-8-4, it was soon hailed by its now immortal name “BIG BOY”.

    The overall length of a BIG BOY is approximately 132 ft. 9 inches, total weight locomotive & tender is more than 1,200,000 lbs., loco service wt-772,000 lbs., tender service wt-427,500 lbs., tractive effort-185,375+ foot pounds, top speed 120 to 150 mph. The tender held 50 tons of coal and 30,000 gallons of water.They served as both passenger and freight engines equally well, surpassing even modern (1950 and 60’s era) diesel engines in power and speed.

    What do all those cunfuddling numbers mean? 4-8-8-4, 4-8-6, 4-4-0, etc. Each number stands for the number of wheels on each “truck”. Let’s use the BIG BOY’S wheel base 4-8-8-4 for an example. The first 4 stands for how many guide wheels there areon the ‘guide truck‘, without these wheels the train would careen off the tracks in corners. The two 8’s (since the BIG BOY has articulated twin drivewheel assemblies for ease in negotiating sharp curves) stand for the drivewheels, take these trucks off the engine and it could go nowhere. The last 4 stands for the cab truck, these wheels hold up the cab and firebox. If not for these wheels the cab would drag on the track due to the weight of the engine.

    Some people called the BIG BOY a Mallet (pronounced Malle) however it’s not. The Mallet’s used high pressure in the front cylinder and low pressure in the rear cylinder systems. The BIG BOYused a HIGH PRESSURE SYSTEM ONLY thus more traction effort. The system had a steam piston in front and back of the driver assembly. With this setup the engine had faster back/forth motion thus faster speed and more tractive effort allowing the engine to pull bigger consists of cars.

    There are two other locomotives closein size to the BIG BOY, Baldwin’s special built 2-8-8-4 Ore Haulers for theDuluth, Missabe and Iron Range Railway. These slightly smaller work enginespredate the BIG BOY by about 8 years. The 4-6-6-4 and 4-6-6-6 Challengers are slightly smaller than the D.M. and I.R.R.R. engines but produce as much powerdue to their greater boiler pressure. Many of the larger engines (2-8-4 or larger) ate so much coal at hard work and speed that the need for an ‘AutomaticFireman’ became apparent. Baldwin designed a gravity feed chute from the Tender to the Firebox and even added blowers to increase the heat as more and more power was needed.

    The problem was not that steam could not deliver the power… it was that the materials used to house and apply that steam could not support the needed power… so Steam engines continued to grow in size and appetite. Baldwin realized somewhere in the 1880’s that the steam being used was often escaping and thus increasing the need for extra water on long haul consists… or high speed engines… So the Steam Water Recycler was introduced on the 4-4-0 Americans of later production… Some later model Challengers had a Water Cooling Unit under the front of the Engine, (Similar to a car radiator)… and some Late Prairie Models had exterior piping running back into the boiler which allowed the used steam to cool and then be reheated and used again… these minimal loss projects allowed Baldwin to release their BigBoy with a revolutionary Top Secret ‘Water Cooling Unit’ that reclaimed as much as 45% of the used Steam from both Driver Assemblies. The Big Boy also had a ‘combustion chamber’in the front of the firebox which was used to burn the half burned coal. The Challenger introduced a Super-Heater assembly that super-heated the boilersteam before releasing it into the driver cylinders…

    Exactly one month before Baldwin released their BIG BOY, American Locomotive Company released a copy of their own also known as BIG BOY. Problem is Alco had a spy in Baldwin Steam Works. There is a difference between the two, the W.C.U. orWater Cooling Unit. Baldwin’s W.C.U. was TOP SECRET and no one alive except those who built and designed the unit knew how it worked. Alco’s copies on the other hand did poorly and caused massive disruption among the Railways. The unit in Alco’s copy did not resend the used steam back to the boiler.

    Baldwin Locomotive Works’4-8-8-4 “BIG BOY” was an ultimate culmination of nearly 180 plus years of steam engineering. From the first “pickle barrel and cast” stagecoach pulling trains through the years via advancements in steam engineering, comprehension, and application to the 4-6-4 Pacific to super-sized compound engines such as the largest, fastest, strongest, and most advanced 4-8-8-4. It was the American icon of industrial power. Unequaled by any European or Soviet Union industrial products. The BIG BOY stimulates the pride and imagination of American inventors to create bigger and better. The type of drive that put a man on the moon.
    Updated May 6th, 2015 at 12:47 AM by EnginneerJoe
  2. oknotsen's Avatar
    Guess what a forum is for?
  3. EnginneerJoe's Avatar
  4. EnginneerJoe's Avatar
    Read what I put up please.
  5. oknotsen's Avatar
    You mean "grrrr"? Doesn't say anything to me.

    If you want to have a discussion, post it on the forum, not a blog.
    If you want to start collecting information, start a website, not a blog.

    Hardly anyone reads blogs.

    Good luck and enjoy!
  6. nathanmallard's Avatar
    Where did you copy and paste all this info from?
  7. EnginneerJoe's Avatar
    I did an English Assignment back in 8th grade and I did it on the Big Boy. One of the old-timers who used to live in Brownwood worked on the Baldwin Big Boy up in Pennsylvania. He talked to me a bit about them. Explained the differences between Baldwin's and Alco's versions. Basically had the equivalency of a 30 year discussion in 10 minutes.