Hope I don't exceed my quota of questions... the second in as many days. My trusty Roundhouse Darjeeling is hardly able to move, even when the boiler pressure is over 40 psi and the safety valve is furiously blowing off steam. I tried adjusting the throttle link with a screwdriver so that the valve opens as far as it can, and briefly the loco went, well, like a train. But only briefly.
In the past the Darj has hauled reasonable loads up a steep incline (4 degrees according to the inclinometer on my wife's Samsung) and has generally performed extremely well. I keep it well-oiled and use filtered rainwater in the boiler. It seems as if there is some kind of a blockage between the boiler and the pistons, or a steam valve not operating properly - but how to find out and fix it?
Curiously, when I switched off the gas at the end of the run, the loco easily ran several yards on the residual low pressure - perhaps on as little as 10-20 psi.
Another curious one. Again, I don't have a Darjeeling so I cannot give specifics... but per your description, I suspect a blockage somewhere in the steam path such that the flow of steam is throttled regardless of where the real throttle is set. Even a blockage in the exhaust can throttle the flow of steam and make the engine sluggish. Finding where the blockage is, and then correcting it can be a problem. Might require some serious disassembly, and not having a Darjeeling, I have no idea what that might entail.
The fact that it ran okay briefly after working on the throttle, and that the throttle is the 1st place in the steam path where debris might clog the system, I would start there. Often, the throttle valve can be disassembled easily (I don't know about the Darjeeling) and I think I would attempt to do so to see if I can find something clogging it up. Pull it apart and see if there is something clogging the output port.
I might try to blow air backwards through the steam passages... from the exhaust, through the cylinders and the valves, back through the steam pipes and the throttle to blow, a (hopefully), easily loosened bit of debris back in to the boiler and then wash it out of the boiler. Hooking a source of air pressure to the exhaust via a rubber tube and then rolling the engine forward and backward will let the air through the cylinders (the engine may even want to run backwards compared to the valve gear setting!).
"IF" you can get to the "end" of the various pipes and such, you could run a small stiff wire backwards through them to scrape and dislodge debris or other build up. Just be careful that the wire does not scrape against any parts that are part of a valve seal such as to scar them or they may no longer seal well. A good source of a stiff wire is a twisty-tie that comes on bread wrappers or with trash bags... strip the plastic/paper ribbon off the wire and it is small and stiff enough, yet flexible enough, to poke into the pipes. Be careful when stripping the ribbon off that you don't nick it, making a place where it might break easily and remain in some bend in a pipe!
Some systems have the oiler in the steam delivery system in the cab and then the pipe goes through the firebox to the front and the oil can SERIOUSLY clog that pipe from being heated ("coked") in the pipe. It can be so bad that the pipe will need to be cut out and replaced! Many people re-design the system to put the oiler at the front so the oil is not added until after the pipe passes through the fire area, or they re-route the pipe to bypass the fire area or at least get it below the fire so the oil does not coke in the heat and clog up the pipe. I have no idea where the Darjeeling routes the steam, so this may not be anything to do with your problem.
If you poke a stiff wire into the pipe at the front of the loco and you get a black tarry substance, then the pipe is probably clogged with coked steam oil and you will have a serious pipe replacement job on your hands.
I know lots of people use filtered rainwater in their Live Steamer, but just how good of a filter is being used and what does it let through that can build up and combine to make large chunks of debris that can float and get into the steam delivery system to clog things up? How often do you empty the boiler and how do you do it (syringe it out, or turn the thing upside down and pour it out or some other method)? If you don't empty it often, you could get a build up of solid particulates.
If you fill the boiler and slosh it around a bit and then pour it out, do you see "stuff" in the water? If so, I would suggest a better filter, or use steam distilled water from the store... (not sure how easy that is to get where you are located... it is easy here in the states, most very grocery store have it by the gallon for less than a dollar, but I understand that it is not so easy or cheap in other countries).
I hope what you find is easily corrected. Let us know what you find.
Semper Vaporo
Pkgs.
Many thanks for the detailed reply.
You may be right that I have not filtered the rainwater enough - I use coffee filters and filter twice, but that said, whereas some of my stored water is still clean, some has started to discolour, so there is a difference in quality. Roundhouse don't mention draining the steam oil at the end of a run, whereas Accucraft do. So I have been guilty of leaving some oil in the system after a run, and perhaps that has contributed to the problem and some biological slime has built up.
I don't feel confident taking the engine apart or probing the pipes so I rang Roundhouse. They said the problem wasn't obvious and offered to take a look for me (great customer service). The only drawback is that I have to deliver the loco to them and the factory is a couple of hundred miles away. I don't trust the Royal Mail not to play football with the package so I may end up driving it there myself.
Will let you know the result of their investigations. It's a shame I have two non-runners at the moment as I've spent the spring and summer building my track layout and was really looking forward to having the two locos follow each other round. The kiddies would have loved it! Maybe I'll be able to put on a demo in the winter instead.
Thanks again for your suggestions.
another possibility is that the O rings on the pistons may have started to fail...I found on one of my roundhouse engines that the O ring was out of its groove. more steam pressure forces the o-ring out of its groove and stops up the works, sometimes it runs fine on low pressure...for a while!
contact your dealer, Roundhouse makes a rebuild kit with new o-rings it is easy enough to replace
Winnegance and Quebec Railway
Eric Schade Gen'l Manager
Thanks for this, it does sound plausible. I have returned the loco to Roundhouse and it is awaiting inspection. My only question is what would have caused the rings to move, since I have not run the Darj that many times? I did notice that from the first time of operation the safety valve was letting off steam, as if the pressure in the boiler was too high. Perhaps there was a constriction in the pipes from day one that later caused a problem in the pistons... no doubt I will hear the prognosis from the factory.
Problem solved - it was the O-ring in the regulator (wrong size fitted when built). So the flow of steam from the boiler to the pistons was restricted no matter how far open the regulator was. So I have been very unlucky (see my other thread about the Peveril) but in both cases the customer service has been excellent, and the repairs have been made with no fuss. Now I am back in operation.
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