In watching video from yesterday's run from Cheyenne to Rawlins with the Big Boy and 844, I noticed something about 4014 I hadn't observed before. It has what appears to be chain-driven mechanical lubricators on the front engine. I know that some overseas steam locomotives used chain drive for some functions, but this is the first time I have ever seen one used on a "modern" American steam locomotive. Was this the original design, or a later retrofit? Was it not possible to work out a solid rod-driven arrangement for lubricators on the front engine? How reliable is this arrangement, and were the chains a weak point on the class as a whole?

The chains go back nearly to the first years in service. They were an improvement over the standard oscillating rod. So as not to speculate, I will let someone else speak with authority. I can't remember the source of my information.

I also wondered about this arrangement, after seeing the chain drive "up close", on the Big Boy in Green Bay. I later read that the original (factory) rods that drove the lubricators were prone to bending. The UP retrofitted them with a chain drive to correct the problem.

Like Mr. Harrod, I also cannot locate the reference for this, at the moment.

JR

Big boy 4006 at the National Museum of Transportation has the same gear on it, but there is a metal guard over nearly all of the chain. The may have left it off for easy access right after the rebuild. There are other changes made during their operating lives. I worked at the museum for 10 years .

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I worked at the Museum of Transportation near St. Louis for 10 years and Big Boy 4006 is there. It has the same chain drive on the front engine, but it has a metal safety guard over most of the chain. I think they left it off for access to make adjustments right after this rebuilding. If you google "big boy 4006" and look at the photos you will see it. Other changes were made during the operating life of these locos.

What's up with the 3-4 copies of the same replies showing up?

I hit the Submit button, but got no feedback. So I hit it again (and again), thinking that my original attempt was unsuccessful. Found out this morning that they all got posted. I guess the other folks had a similar experience.

JR

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Thanks for the replies and clarifications.

I took care of the duplicate posts. I'm not sure if I fixed the problem.

Hello,

So I don't start ANOTHER thread.....I'll add to this one...

There is a sea of posts and information out there but I wanted to quickly ask if the Big Boy has roller bearings on the main driving axles. With a quick scan I am not seeing if they do have them.

Can any of you advise? Maybe it's an obvious yes?

Thank you.

Randy

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Kelly,

Thank you for the confirmation.

Regards.

Randy

Another question: in the runbys, it sounds like there is a side rod clank on the BB. Is that right or is it something else?