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Hero Steamer
Joined: January 31st, 2009, 10:37 pm

November 3rd, 2012, 9:17 pm #31

that's great loved it

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Joined: March 25th, 2010, 9:29 pm

November 3rd, 2012, 10:27 pm #32

Keith S hits the nail on the head - coal firing is a whole different order of business. I will probably do it again, but never on a club running day, there is far too much potential to get in everyone's way and stall at awkward places around the track with Rocket.

The Rocket is a reliable people-hauler (odd to say for such a small loco, but it is simply like that - at club occasions, it will run all day long with me at the controls, and three kids on a second wagon behind me) when fired on gas. If you need more power, turn open the gas regulator, 15 seconds later, it's there. Safety blowing ? Put the axle pump on, or pump water manually when stationary. Boiler full ? Then reduce the gas.

On coal, one needs to use the steam blower far more aggressively, and this is where trouble begins.

You need steam pressure for three purposes:

1. blower, to keep the fire going
2. moving
3. pumping water into the boiler

They are all part of the same feedback loop, and both using the blower and moving the loco will also consume water.

So if you use up steam for moving, the boiler level drops, pressure drops, the blower is less effective, and the moment you need to pump water into the boiler, pressure plummets and the fire goes out.

In addition, the fire is hottest when you're almost out of coal to burn - but if you add coal, steam generation drops for three minutes or so, until the new coal starts burning well.

The key is really to resist moving the loco until you've topped up boiler water to the maximum, and the safety is about to blow.

And coal, you need to add in very small amounts, and frequently.

Not that I had all of that pat down ... the weather was horrible, I dropped the camera, which led to the loss of about 45 minutes of video with all the preparations, lighting up with the blowlamp, and a few good, fast circuits of the track. By the time this video starts, you can see that I had to add coal - the safety was blowing off, coal is added - and, nothing! Minutes to wait before pressure is back up.

By that time, also the water glass was starting to act up, so after two more circuits in the rain, I called it a day. When your water glass seems empty and you're not quite sure whether it's just a bubble or you're really out of water, is the time to call it quits when firing on coal. Damage from an exposed crown sheet is very expensive to repair ...

Now, without further ado, here is the video - enjoy !!

Sorry about the raindrops on the lens - it really was raining quite hard at the end :?

One last thing I want to show you tomorrow is clean-up and readying for winter storage/display. See you all then!

Steam Legend!!
Joined: October 28th, 2008, 4:55 am

November 4th, 2012, 1:25 am #33

It's certainly a juggling act getting every thing right, great job, I enjoyed that.
BK (Bernie)

If it aint broke, don't fix it.

Steam fanatic
Joined: May 7th, 2008, 4:21 pm

November 4th, 2012, 3:17 am #34

Thank you for two very entertaining videos :)
While you're resting

Full member
Joined: September 13th, 2009, 6:20 am

November 4th, 2012, 4:11 am #35

Enjoyed the videos very much . Thank you. :thumbs:
Cheers Lenny
I like it hot.

Full member
Joined: February 3rd, 2012, 10:55 pm

November 4th, 2012, 6:09 am #36

Awesome!!  :D  i know what a pain it is to keep a small coal fired engine going!   :evil:  Cant wait for the next part!


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Joined: November 3rd, 2007, 10:28 am

November 4th, 2012, 7:42 am #37

That was very enjoyable, thanks for persevering with the coal. :D
Les - Don't panic - it's your round next. :D

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Joined: September 20th, 2011, 9:27 am

November 4th, 2012, 7:44 am #38

You show very well what a challenge it was to get a coal fired run. I had no idea it was such a challenge.


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Joined: March 25th, 2010, 9:29 pm

November 4th, 2012, 2:37 pm #39

Well, it is sunday afternoon for me, so it is about time to put the last exhibits on the table, about 20,5 hours prior to the ending of STWWW 2012 - does this mean my table will end up all the way at the bottom of the loco shed ? :D

Coal is filthy stuff of course, and there is the accumulated dirt, grime and carbonised oil from the past running season sticking all over Rocket, as well as some small repairs and adjustments that need to be made.
On the last club run, something worked itself loose about every hour. Chimney brace screws are a favourite to come off, tender sideboard nuts are as well, and on that last club run, a cylinder mounting plate came off mid-run, and it turned out one of the mounting screws for the other one had also disappeared. :shock: It wreaks havoc with the timing, that much is for sure! (luckily we were running at a model engineering show, so M3 screws were easy to come by - 30 minutes later, Rocket was back in business. The most difficult part is not to try and start on the job before it is cool enough not to burn your fingers!)

One of the last things to fall off, as you might have seen in the first video, was Rocket's right hand nameplate, so we had to glue that back on as well.

First off, we start with covering everything in the neighborhood with paper, just so we don't make any oil or water stains.

The grates had already been removed and cleaned at the end of the run, so now we open the smokebox door - hmm, it's black in there!

As far as we can reach them, we brush out the flues.

Some of the flues are completely unreachable, without disassembly of the entire smokebox - but that will be something for the bi-annual maintenance I think. I would also like to see whether gas-firing will succeed in cleaning the flues back up a bit.

Other flues, on the other hand, are right in front of the firebox door, so you get this ...

This is the end result:

Then follows a cursory vacuuming session to get all the loose ash, dust and bits of coal off. Further cleaning with a screwdriver wrapped in paper to get into all those difficult-to-reach corners.

Rocket is put onto its nose (and you see, Dave S, the chimney crown comes off, so if I ever buy a chimney fan, it will just fit on there) and further cleaning of the wheelthreads, axles and bearings, spring mechanisms and valve gear ensues.

This is the icky side - lubricator oil goes everywhere. The O.S. Rocket has a provision for negligent owners, where steam oil condenses into the chimney, then runs down into the smokebox and drips out, right onto the eccentrics for the valve gear. It is hard to figure out whether this was by design, but as a result everything gets filthy down there. Rear wheels and suspension are nice and clean already.

I tried to photograph the front wheel suspension which I adapted, but it turns out to be impossible to get a picture of without major disassembly. I have no idea how I mananged to assemble it in the first place, it did involve allen keys and fingers through the front wheel spokes.

Then the tender needs the same kind of attention, although it remains a lot cleaner - only one drop of oil on each bearing box for every run, but there is of course the rust from the rails to contend with.

Finally, we make a note which fasteners still need to be replaced - if anyone knows of a source of black M3 allen bolts, it would be much appreciated. I have used brass bolts for now, but the jury is out on whether they will turn out to be strong enough.

We still have to glue back the name plate on the right hand side as well! I bought glue which advertises to be "resistant to anything" ...time will tell!

We used quite a bit of paper for our cleanup - I wonder whether a paper-fired Rocket would be doable... ?

Finally, I thought that I might also show you the last bit of preparation for the new season, that I can just as well do right now - preparing for the spring hydraulic test. This is a little more involved with Rocket. For this there are two reasons - the boiler inspection kit does not come with an M11 screw fitting, which is Rocket's thread for the safety valve - this means we will need an adapter, and secondly, due to the antiquated design for the throttle, it has a tendency to leak. No problem in normal operation, but it is a problem if you have to hold 10 atm of hydraulic pressure for 20 minutes.

So, here's what to do:

First, you take off the fake steam dome:

Then, the real steam dome:

Rocket did not have a steam dome originally, and was quite prone to priming. One was provided later, and also on the replica there is one. Here, we have a proper steam dome, with the dry pipe sticking up all the way near the top.

This pipe, you have to take out - I glue it in with some plumbers' compound that is supposed to be good for heating pipework. It comes apart easily (in fact, it is difficult to establish whether it survived repeated steamings at all), and leaves a hole. To prevent the regulator from leaking, we have to plug this hole.
For a hydraulic test, it would be prudent to fill the dry pipe completely with water. If you plug it from this side, it is subject to the entire test pressure, whereas it normally is equalised with the boiler pressure. This makes it somewhat liable to collapse on the occasion of a hydraulic test.

Plugging, we do with a rubber stopper:

Then we unscrew the safety valve:

And put in the M11- 1/4in adapter for the test manifold.

Boiler appendages get stored safely in the tender.

The M11- 1/4in adapter provides for a convenient hole in the boiler (also the blower and blowdown valves are kept open), which allows it to dry out further, without undue stress on Rocket's appearance for display.

And to top it all off (literally) we also refill the lighter - it has caused no small amount of trouble these last few days!


All ready for winter display!

And finally, the portrait of a clean and prepped Rocket, complete with STWWW on the computer.

Signing off now on the STWWW 2012, once again thanks for all the comments, and have fun - I certainly did!

Last edited by stenella on November 4th, 2012, 4:29 pm, edited 1 time in total.

Joined: July 19th, 2006, 3:12 pm

November 4th, 2012, 2:46 pm #40

Excellent video.

Loved every minute.

What surprised me was the speed the Rocket could attain.