I just mounted the cylinders (2.25 x 3.5 inches) to the frame of my first engine which
is a NG 2-4-0.
When I finished bolting them on I started thinking about the cylinder drain cocks that
go on the bottom of the cylinders.
Since I haven't had any experience with them I was wanting some feedback on the
types such as manual vs automatic, as well as who supplies them?
Aaah...a very well covered topic on Chaski. Harness the braintrust by going here: http://tinyurl.com/46xpvzs (I shortened the URL because Chaski itself ironically didn't like some the characters in it, messes with the BBcoding.)
You'll see your own thread on top
Lots of good stuff in there. Check some of those out first then post any further questions....
Railroad Rick wrote:NG 2-4-0....manual vs automatic
A narrow gauge engine of that size will almost certainly have slide valves, right? Old engines would have manual cocks, which are just fine. If you forget to open the cocks, the water pressure in the cylinder will just lift the slide valve and spit the excess out the stack. This happens to me all the time, especially when starting out from the steaming bay with the cylinders full of condensation. I've learned to give the cocks time to drain, as it takes a while! Four hours to polish brass, and five seconds for the hot water from the stack to splotch it all up!
Cylinder type valves could be damaged by water compression, so they usually have automatic-type cocks (wild generalization). I have lots of pictures of engines steaming around with their "automatic" cylinder cocks open. Rust scale from steel boilers locks them up tight...
There is a definite downside to steam operated automatic cylinder cocks, they do seem to get clogged up quite a bit. We have the SuperScale auto-manual steam operated cocks on the MEG, we'll see how those go. Those automatically open when forced by a water hammer action, and you can also command them to open by shutting off the steam control pressure. Steam must be applied to keep them closed. An upside is that you can never forget to leave them closed when the engine is cold.
The ones on my Chloe are mechanical, they are rotary valves with an adjustable linkage and something we came up with, improved from a 2009 Live Steam article about cylinder cocks mentioned in that thread I linked. They are very reliable but the mechanism hangs low and is delicate - because of that we have added a strike plate, which has saved its bacon numerous times, mostly when loading and unloading over uneven track panel, and the occasional but rare de-railment. The cock bodies themselves have a bevel where the hole is, rather than an angled tube hanging down. This is because the ground clearance on a Chloe is nonexistent.
Bill shields has some good designs for a manual cylinder cock that he is usually willing to email.
-M
Attachments
Live Steam Photography and more - gallery.mikemassee.com
Product Development and E-Commerce, Allen Models of Nevada
Always the problem with NG engines. If you have not made any holes, do not put them on the bottom. Angle them from off center and get some extra ground clearance. Compare between ground clearance with them straight down and if they are 20-30 degrees off centerline. Also do not forget they are already further out from the track centerline and the builders of the track may have put something out there to knock them off.
David_T wrote:Always the problem with NG engines. If you have not made any holes, do not put them on the bottom. Angle them from off center and get some extra ground clearance. Compare between ground clearance with them straight down and if they are 20-30 degrees off centerline. Also do not forget they are already further out from the track centerline and the builders of the track may have put something out there to knock them off.
i did that on my Chloe only to find that even with them angled out they still hit the rail head and break off. on the Chloe, however, they are very very close to the track.
Skidplate fixes all. here's some photos. It's practically invisible under normal viewing conditions.
Saved the bacon a couple of times already. If the engine de-rails, it just slides on the skid, which goes all the way across. And it's practically invisible under normal viewing conditions, doesn't take away from the engine at all.
Sorry bout the mess in the close ups, the brass hasn't been polished after the last couple of runs.
Attachments
can you spot the skidplate?
Live Steam Photography and more - gallery.mikemassee.com
Product Development and E-Commerce, Allen Models of Nevada
