Thursday, 20 July 2023

Achilles Report No81: Tinkering Times...

Evening all. In the last post we saw "Achilles" return to her home track at Ryton Pools for a typical annual steam test which, I'm glad to say, she passed. However, as always with steam engines, there were a few niggles that needed to be addressed to keep everything in fine fettle. This post will discuss the tinkering I've done with the locomotive over the last week or so since the run. The first job was to tackle the loose chimney which was dancing around all over the top of the smokebox during the run. The bolts in the petticoat were well worn (not helped by the fact that they get shot blasted by ash on each run) and so the petticoat was removed and re-bolted...
To aid the new bolts I also added some heatproof sealant to ensure that the petticoat would provide the best possible smokebox vacuum. It was now solid again...
Once the petticoat was sorted the chimney casting (which slides over the top of it) could be replaced. My next job was to look at the snifting valve which sits behind the chimney. The snifting valve screws into the wet header of the superheater and is supposed to aid free running when steam is shut off. The opening of the regulator in theory pushes the ball up against its seat, closing the valve. However, when the regulator closes the ball should drop back, allowing any vacuum created by the pistons during coasting to draw in fresh air from behind the chimney rather than sucking debris down the blastpipe. I have never really messed with this little valve before but it was passing quite well under steam so I had it out and recut the seat to try to help it seal better when the regulator is open, thus saving a bit of steam from being wasted...
This valve has probably not been opened since the engine was completed in around 1986 and so I was amused to find that the suction seat (as it were) was also providing a seal! Therefore, it wouldn't have worked anyway as the ball would be sucked back against the underside seat and would not allow any air in. It might as well have been replaced with a bolt! Therefore, I cut a cross into the bottom seat to prevent it being able to seal in that direction so that it would actually do its job. Once put back together and cleaned, the snifting valve was refitted. Next stop, job number three...
During the last few runs the handpump has become quite weak on the engine, not helped by the fact that it is probably only used during steam tests and dire emergencies. (Since I replaced the double acting axle pump the handpump has been required even less frequently). Though it passed the steam test as it did actually work, I felt it was time to remove it and have a look at what was going on. It was removed during the repaint a few years ago but as it seemed to operate correctly at the time I chose to avoid messing with it. Sometimes it's better to let sleeping dogs lie...
After the handpump was removed I decided to have the feed clack off of the LH side of the boiler to make sure that was okay. Sure enough, it was passing a touch and this was duly rectified. I'm not convinced that it still won't pass a tiny bit but at least I now knew it wasn't blocked or failing. This was then refitted...
The handpump was stripped down and I found that the balls were cloudy and worn, the seats were both quite poor and the rubber O ring on the piston was pretty much none existent. All three of these issues would be addressed and the lift on both sides of the pump reset once the new bits were installed. With the pump out and now waiting for balls and a seal, I moved on to a small cosmetic job that was now accessible to me: putting some fresh paint on the doorplate in the cab to refresh it. As always, I couldn't help but think that whilst the paint was out I might as well redo the smokebox. After careful masking up and painting, the smokebox looked a lot tidier again...
Whilst messing around in the cab I decided to do a completely pointless job: burnish the firebox door handles. Why you ask? For the sake of it really! Past experiences at Tyseley on the beautiful 5043 have made me love burnished firebox door handles. It's not a hard job either, requiring only some grey scotchbrite, autosol polish and elbow grease. It certainly passed a drizzly evening away...
With the cab off it's also much easier to access the cab fittings and I decided to give everything a buff up whilst I could get to it all. The gauge glass blowdown fitting was also removed prior to painting the doorplate as this had leaked slightly against its pad and chalked the boiler. Removed, polished and refitted with a new seal: it looked much better. The polished manifold and firebox door handles also looked a treat...
A few days later the seals for the handpump arrived in the post and I got everything rebuilt ready to test it in the sink with the new seals and balls. The result was a mixed bag, despite being put back together exactly as it was for the previous decades! Some messing around in the sink allowed me to recalculate the lift on both sides of the pump for optimum performance and after some tinkering the pump worked an absolute treat. It was soon refitted and resealed into its tank on the LH side of the engine. In the tank I also made a slight adjustment, standing the pump off the bottom of the tank further to prevent it drawing in any muck. The original height saw the suction side incredibly close to the bottom of the tank where the muck tends to form...
The tank was then rebuilt, with the next job being to cut and fit the new gauge glass and rubbers. The old one (again original) broke when it was removed this time around, with the perished seals no doubt having clung to it and snapped it whilst the top and button nuts were loosened. The new one (5mm glass) was fitted into place and nipped up on its new rubbers. Only a test steaming will let us know for sure if it's okay... 
The final job from this period of maintenance was the refitting of the whistle and its pipe, the latter of which had been removed for shortening. The whistle pipe on the engine has always been too long and was bent into a pigs tail to allow it to fit beneath the cab floor. This meant that it filled with water and produced a dull note when the whistle was blown until the condensation cleared. Not so local alarm clock snoozer Eddie the Late kindly agreed to allow me the services of EJ Steam Engineering Ltd and soldered me a new nipple onto the shortened pipe before posting it back to me. I still need to learn to silver solder but things like that happen years apart for me so the help of a good mate once in a blue moon seems to be all I need! Once the whistle and pipe were back on, the engine was buffed up to her usual standard in readiness for a test steaming...
I'm not a betting man really so I don't think I'm going to be brave enough to take the engine to Ryton for its test steaming...I'll probably throw it on the rollers. If it was just the one job I'd done then maybe I would but with five or six things having been messed around with over the last week or so it's probably best to try it at home first to save any embarrassment at the track. That's not to say I'm not confident it won't work...it might, but then again it might not! You never know with these things. Thanks all for reading and fingers crossed I've solved some of the issues. Cheers, Sam...

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