I just have a couple questions, steam and diesel related

[pimpz26]

My first? What is the "clicking sound" that hear when a diesel loco is sitting idling? I have even heard this sound on trains that pass by moving slowly.

Second? I have been to several railroad museums and have noticed that some steam locomotive have either had the side rods removed or cut. What is the purpose of doing this? I have seen this done in several photos as well. The BigBoy that is on display in Dallas TX had the piston rods torched off and several side rods and valve gear rods removed.

[gabe]

I am no expert, so if another forum member says differently go with their response—there are so many people who know more about trains than me on this forum.

But, I am pretty sure the clicking noise you are hearing is the air pressure regulator. When too much air pressure (from the brake system, I imagine) is built up, there is a valve that lets off the pressure and the “click” is the valve releasing.

I imagine the reason you see the roods cut for steamers at museums is because it makes transportation of them easier. The rods are connected to the pistons—which often are unsuitable for even dead motion. Thus, cutting the rods is the most cost-effective way to circumvent that problem and transport them—via rail—from point A to point B.

Hope this helps.

Gabe

[dldance]

Yes the clicking is from the air tanks - but it is a valve that drains water from the system. Compressing air, compresses the humidity in the air into liquid water, which really damages the air system. So these valves were invented to keep the system clear of water. Imagine if a few drops of water froze in the brake cylinder.

dd

[jchnhtfd]

Taking the rods off (which is preferable to cutting them... although people do do it, unhappily...) makes it possible to move the engine without moving the pistons or valve gear. Since both require lubrication, which it is unlikely that a dead in tow engine will get, it prevents damage. One can have some interesting imbalance problems, though -- but it is unlikely that the tow will go fast enough to cause a real problem.

[Overmod]

There's more of a problem, I think, with the moisture in the condensate causing corrosion in the (steel) reservoirs and lines, and mixing with the lubricant in the triple valves etc., than there is with a potential 'hydraulic lock' in the brake cylinders (or having them freeze in cold weather).

Piston rods are easy to cut -- anything else requires tools, usually fairly large tools, to remove, and you need some sort of hoist or crane to handle the removed pieces, which are usually rather heavy...

You might pull the key between the crosshead and the piston rod to disengage the two for transport -- but ask the Dead Goat people about the fun involved in doing this even with narrow-gauge locomotives...

Moving locomotives without siderods was often done by putting special bobweights on the crankpins (there are some pix in Staufer's book on NYC Hudsons). Theoretically, at least, you could have sets of these that would balance any part of the rotating mass that could be statically balanced (including the fraction of the main rod that revolves with the big end as opposed to sliding with the crosshead). That would let you transport locomotives with any combination of rod or valve-gear parts removed.

My opinion was that lubrication on a dead engine might not be too difficult, since mechanical lubricators were often driven off derived motion, such as via a link to the valve gear. If that is connected, the lubricator should be workable. Grease, Alemite, etc., should work just as well on dead engines as live ones.

[coborn35]

QUOTE: Originally posted by dldance

Yes the clicking is from the air tanks - but it is a valve that drains water from the system. Compressing air, compresses the humidity in the air into liquid water, which really damages the air system. So these valves were invented to keep the system clear of water. Imagine if a few drops of water froze in the brake cylinder.

dd

Right on target. On NW5's, the clicking gets rather loud and/or annoying.

[pimpz26]

Thanks for the info.