Can anyone tell me what the plastic water drums are for on the winch stations, they seem to have metal plates in them that look like they had electric cables attached to them. I'm new to mine exploring and can't think what they could be.

Electrical resistance braking. Salt water in the drums (brine baths). Very clever! Google "Liquid Rheostat" :thumbup:

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Some of the larger oldish motors in the mill I worked at used similar for starting load control.

Yes and I've seen them in electric locos and also as a load-cell in small hydro stations, used to soak up surplus juice when synching the runners with the grid. They are slightly frowned upon these days due to OTT H&S meddlers who are scared that folks will get electrocuted or will go and stick their heads in the drum or something.... 😞 ::)

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The local colliery had a massive one in the winder basement, huge tank with a pump to circulate the electrolyte.
Whole unit was well encrusted in salt, seemed a bit strange as the winder and compressor houses were immaculate. (2X Belliss & Morcom compressors)

The liquid resistance they used on the steel rolling mills at Corby -it added rotor resistance to the motor of a motor generator set (Ilgner set) when an ingot went through the mill so energy was supplied by a 40ton flywheel on the motor generator shaft thereby reducing the massive peaks that would otherwise have been drawn from the Grid, used washing soda - sodium carbonate. I believe this was the most common electrolyte.

We still use them at Wylfa Power Station - to control the speed of the secondary AC pony motors driving the reactor gas circulators... (If we lose the main 11kV main motors, the gas turbine emergency gen sets kick in and drive 2 out of the 4 3.3kV pony motors to keep the reactor core cool)

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Thanks everyone, going back soon to get more shots.

Nothing that big in the paper mill I worked at, probably 400 HP max.
Cannot remember all the details but seem to remember a lever on the motors which either shorted the rotor and/or lifted the brushes off the slip rings once up to speed?

Hi All

Salt water NOT used for DC liquid resistances - would generate Chlorine Gas! Usually some other solution involved. AC liquid resistances not as crucial, but still tend to use some other solution. Oakelely's 500V AC motors had purpose built liquid resistances - but the spec did not match the actual required performance, so extra cooling tanks had to be added due to the frequent starts. AT least one had a stream diverted through it!

Here's one:
flink]Oakeley-in-the-1980s-Image-032[linkphoto]Oakeley-in-the-1980s-Image-032[/linkphoto][/link]

And the tank:
🔗Oakeley-in-the-1980s-Image-031[linkphoto]Oakeley-in-the-1980s-Image-031[/linkphoto][/link]

One in action(!):
🔗Oakeley-Slate-Mine-Archive-Album-Image-016[linkphoto]Oakeley-Slate-Mine-Archive-Album-Image-016[/linkphoto][/link]

The same one but dead:
🔗Oakeley-Slate-Mine-Archive-Album-Image-010[linkphoto]Oakeley-Slate-Mine-Archive-Album-Image-010[/linkphoto][/link]

And as resurrected for display only:
🔗Oakeley-Slate-Mine-Archive-Album-Image-002[linkphoto]Oakeley-Slate-Mine-Archive-Album-Image-002[/linkphoto][/link]

Maenofferen equivalent:
🔗Maenofferen-1981-Image-027[linkphoto]Maenofferen-1981-Image-027[/linkphoto][/link]

I have drawings of the BP equipment if anyone's interested.

Grahami

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The Oakley ones look (as far as I recall) as the same as at Penyorsedd for winding the blondins.

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I think the box that you can see in this photo atop the Chamber 34 incline head in Oakeley/Cwmorthin is one.
🔗Cwmorthin-Slate-Mine-User-Album-Image-90531[linkphoto]Cwmorthin-Slate-Mine-User-Album-Image-90531[/linkphoto][/link]
We were having a look at that last night, when I was puzzled that brine would be contained within cast iron without leading to massive corrosion. Some form of anodic protection was suggested - anyone know if this is likely?

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Although the Wiki article mentions salt I'm inclined to agree with grahami and seem to recall some sort of soda solution.

So it seems the ones at maenofferen are very basic compared to others. But they all work on the same principal.

I think the box that you can see in this photo atop the Chamber 34 incline head in Oakeley/Cwmorthin is one.

Dead ringer isn't it? I knew there was some reason that we had to go up there. Well done Blober! :thumbsup:

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I think the box that you can see in this photo atop the Chamber 34 incline head in Oakeley/Cwmorthin is one.

Dead ringer isn't it? I knew there was some reason that we had to go up there. Well done Blober! :thumbsup:

Absolutely!
Trouble is, we need to climb back up to get some photos now. 😞

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Trouble is, we need to climb back up to get some photos now. :-[

Hmmmm....if only we had a way of getting up there, a ladder or something... :lol: :lol: :lol:

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I think the box that you can see in this photo atop the Chamber 34 incline head in Oakeley/Cwmorthin is one.
🔗Cwmorthin-Slate-Mine-User-Album-Image-90531[linkphoto]Cwmorthin-Slate-Mine-User-Album-Image-90531[/linkphoto][/link]
We were having a look at that last night, when I was puzzled that brine would be contained within cast iron without leading to massive corrosion. Some form of anodic protection was suggested - anyone know if this is likely?

This any clearer?
[tweak]links tweaked[/tweak]

Yes, the Oakeley Chamber 34 is the same type and size as at Penyrorsedd. Suitable for up to 75HP or so - those big Oakeley incline motors were 200HP so a different design was needed.

Penyrorsedd ones in working order:
🔗Penyrorsedd-Slate-Mine-Archive-Album-Image-020[linkphoto]Penyrorsedd-Slate-Mine-Archive-Album-Image-020[/linkphoto][/link]

🔗Penyrorsedd-Slate-Mine-Archive-Album-Image-019[linkphoto]Penyrorsedd-Slate-Mine-Archive-Album-Image-019[/linkphoto][/link]

Cheers

Grahami

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In the early 1960s I was taken around Fylingdates BMEWS by my American uncle who was a civil engineer with the USAF, some time before commissioning. (Security was quite another thing in those days). The powerhouse was running under test at the time with about 10 massive diesel generators each in the 3-4Mw class at least. Outside the house they had set up very large tanks as load banks from which a great deal of steam was emerging. There appeared to be a framework made of scaffolding over each tank which I assume was to hold the electrodes. Uncle's advice was "you don't want to go near those - you'll end up as a crisp!". I notice that in some of Maeonofferen pictures you can see a rudimentary barrier around the rheostat, but in others not. I can't imagine that these things being used today unless in a cage. I suppose in an earlier age they were a little more clavier with HV.