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Oldmechthings

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I'm still chipping away at the model steam shovel. I sure don't do much at a time, but every little thing, no matter how trivial is progress.
Some of the piping and a couple control levers are suspended from the roof, so I have started building a cab framework to hold them. Also some of the boiler fittings need to be coordinated with the roof line, so I'm working on the two together, so everything will fit when completed.



Yesterday My entire efforts in the workshop barely made a teaspoonful. The valve bodies for the try cocks for the boiler.



And they are not much more than half finished. They still need stems and valve handles. Oh well, my hobby is my "pass time" and it sure does!
Birk
 

mklotz

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Birk,

Since you brought up trycocks, perhaps you can answer a question for me.

I've seen model boilers fitted with both a sight glass and trycocks. Unless I'm missing something, that seems redundant. It's my understanding that the trycocks are used to determine the water level in the boiler - perhaps I'm wrong. Why would both be fitted? Do folks not trust the sight glass?
 

kellswaterri

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Hi Birk, there would't happen to be a drawing about showing how those little trycocks are made ? I would like to try and make my own.
All the best for now,
John.
 

Oldmechthings

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Mklotz
I am pretty sure that the old boiler codes specified two separate methods of determining the level of water in boilers. Sight glasses are not always reliable. Occasionally they get a plug in one of the fittings. Also there is a chance that they could get broken, and many had a way of shutting off the water and steam, and that way they could keep the machine and crew in operation until the boiler could be shut down for repairs.



John
The try cocks are of my own design patterned after looking at a picture of some real ones. Basically they are just little needle valves. If you have access to Live Steam magazine March/April 2003, page 58, there is a sketch of one, along with a couple other boiler fittings that were used on the Buffalo-Springfield steam roller. The steam shovel is a smaller scale so I'm just scaling things down, and using whatever thread sizes will fit in the smaller size.

Hopefully that answers the questions for both of you.
Birk
 

kellswaterri

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Hi Birk, had another study of the ''SPOON'' ;) and now think the idea has sunk in...
All the best for now,
John.
 

compound driver 2

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Hi
Tricocks are fitted to sight glass columns to allow the gauge to be shut of should a glass be broken in use. In practice the chances of getting to the cocks with 200lbs of steam venting from the broken glass are slim.
Old boiler code asked for a minimum of two methods of getting water in to the boiler but not two ways of checking water level. Two columns are fitted to allow the engine to continue should a glass not be replaceable out on the road or the track.

All of my traction engines have tri cocks once the first steaming is done and time has been found to make the tri cock gauge. In all the years I have steamed both model and full size I have never had to use the tri cocks nor would I want to i like the skin on my hands. I did how ever know a chap that made tea from the dripping water from a bottom drain cock on a Fowler, He was the only one brave enough to drink the boiler water, we prefered the water from the tender. That also stopped when we found how much pond scum had been lifted into the tender tank! I like tea but not enough to drink pond weed and frog sporn.

Cheers kevin
 

DickDastardly40

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Birk,

Wonderful job there, better a teaspoon of quality parts than a ladle of potential recycling.

On the subject of gauge glasses, the Y136 and Y102 boilers I did my certification and subsequent experience on had 2 gauge glasses piped directly from the steam drum and an IGEMA* remote level indication at plate level. If ever there was a conflict in what the levels said, a gauge glass drill was carried out:

1. Shut Steam, Shut water, Open drain, the glass should empty.
2. Open Water, Get blow of water, Shut water.
3. Open Steam, Get blow of steam, Shut steam, Shut drain.
4. Open water, level should rise to top of glass.
5. Open steam, level should fall to correct level within drum.

* I Give Exact Measurement Always.

Best Always
 

Steam4ian

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G'day Kevin

Where tubular water glasses were fitted to F class tank locos on the SAR South Australia not South Africa the water and steam shut-off cocks had chains attached to the levers. Idea was the crew pulled the chains as they exited the cab. In an enclosed cab they would want to be getting out pretty quickly. The more modern locos (post 1926) had prismatic water level gauges but no chains on the shut-off cocks.

Regards,
Ian
 

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