-----Original Message----- From: Kevin O'Connor <[EMAIL PROTECTED]> To: Multiple recipients of sslivesteam <[EMAIL PROTECTED]> Date: Sunday, May 27, 2001 2:50 PM Subject: Boiler water level; Rubys and others (very long version) >snip< >"Zippiness" commences at the point that the boiler water level falls low >enough that the potential carryover caused by bursting steam bubbles is no >longer a problem. At this point the boiler/burner is delivering the >"driest" saturated steam to the cylinders that the combination can. The >locomotive will then continue to "zip" right along, running real well, until >the water level drops low enough to start to uncover the top of the >firetube. At this point the locomotive will start to act "tired" (this is >what I said in my original answer) as the firetube's effective steam >generation area starts to fall as the water level goes down. The locomotive >will continue to "tire" until it finally stops when there is no more water >to boil. > >snip< Kevin Your explanation of the phenomenon we all experience is exactly right. The only time a locomotive doesn't operate this way is if it is grossly overfired. When this happens (the Aster Mikado is a perfect example) the locomotive can remain "zippy" from the time carryover ceases until the boiler is almost out of water. In fact, my Mike used to run its absolute "zippiest" at less than 1/4 full--water well below the tops of the flues. I suppose Aster designed the locomotive this way to make it very forgiving of less than perfect attention to boiler water level but the design makes it terribly wasteful of fuel. Now that I've added full control of the firing rate to the burner, it behaves the way it should--following your description exactly. Victor Lacy
