This also died out a while back - this is the second form of Cooke & Hunter's Tunneller. This is from the 1866 patent - the patent includes the double-bore trepanning head and the previous single trepanning head - so presumably you either had a couple of these things, one with each, or like some monstrous Iron DIY kit you could change the cutting bit at the front as required. (BIG overhead cranes needed) I've never seen a tunnel which could be ascribed to the drum type tunnelling head - it would have quite a distinctive floor as it cut its own drainage channel as it went along.

🔗Personal-Album-54-Image-016[linkphoto]Personal-Album-54-Image-016[/linkphoto][/link]

Wonder if this version was ever built - the patent drawing is quite detailed!

Graham

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[tweak]GrahamI, I've moved your post on the Cooke & Hunter Tunneller out of the other thread. Felt it was a bit lost there amongst the off topic chat about pre-historic sea scorpions and massive spiders.[/tweak]

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Fine - bit of a dinosaur myself I suspect...


Graham

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I'm being thick, but how does it actually work?!

Presumably you need a fairly decent power source behind it, which must come in through the shaft at the back. Putting aside the fact that the drive shaft doesn't look thick enough, it then seems to split the power to a shaft either side though a magical-looking system and then drives what I presume is the twin cutting head.

I'd guess that the double cutting head rotates around the long axis of the device, which gives you a round bore. Admittedly that introduces a bit of an issue in terms to the amount of rock/cutter contact, but that's probably resolvable somehow.

But... the chassis doesn't look as if it does allow rotation and in the plan view, it looks like it's got three drums which cut - a large centre one and two smaller outer ones. That's going to result in a very odd-shaped tunnel which isn't actually of much use unless you go back and re-do the edges.

So... where have I gone wrong?

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How big was this machine? Is there a scale or measurements that accompanies the image, please?
Any idea of what the teeth/cutters would have been made from?

The first form (1864) is shown here:
🔗Maenofferen-Slate-Mine-Archive-Album-Image-031[linkphoto]Maenofferen-Slate-Mine-Archive-Album-Image-031[/linkphoto][/link]

And cut a tunnel of this size:

🔗Maenofferen-Slate-Mine-Archive-Album-Image-024[linkphoto]Maenofferen-Slate-Mine-Archive-Album-Image-024[/linkphoto][/link]

I'll have to check over the whole original drawing for any indication of scale for this monster - but I would imagine anything from the same size as the earlier one up to twice the size! (I'll re-read the patent to check if it was meant to work within a tunnel cut by two full size trepanning discs.)

As for explanations, the whole thing relates to Hunter's infamous saw and it's tools. I'll transcribe the later patent and add some related details later on today .... when I get a minute.

Graham

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Thanks for that. I see! Presumably the cutting head/s of the two models were to rotate at some speed rather than a slow speed, grinding action? Water lubricated or dry?
Is it known what total length of tunnel one model of the first form ever achieved?

Good drawing 🙂 Presumably getting rubble away from the front of it would be an interesting task, but probably wouldn't need to have the whole thing backed up whence it came.

I'm still utterly confused by the 1866 version though. I'm trying to resist the temptation to pop to my parents' house, dig out my old Lego and try and build a model of it to see if I can work it out...

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Briefly (!) the principle of the Hunter tooth and it's derivative machines was slow speed and heavy feed - and yes they did grind the rock away. "The cutters are steel bolts with conical heads forged to shape; the heads are turned to a sharp edge all round and are then hardened." A typical Hunter saw had a pair of blades each 3-4ft in diam with a number of sockets for the cutters round the edge (I'll post some drawings later). These had a peripheral speed of 45ft/min combined with a feed of 3-6in per minute when dealing with blocks up to 18in thick.

There's one of the few pictures of such a saw at http://www.penmorfa.com/Slate/Archive2.HTM 

The second patent mentions fitting some sort of ploughs to remove the rubble from the formed trench beneath the machine.

Graham

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The 1866, 2nd. version is three, vertical, grinding wheels giving rise to a tunnel rather cross shaped in profile. Am I correct?
The first model worked rather like an apple corer and it would have been by far the easier to withdraw the machine and use the same winding gear to enable the use of a waste wagon at the core face and allow room to work the waste.

That's pretty much the same conclusion I came to!

The problem with the thing is the amount of cutting it's going to be doing at any given time (basically half the circumference of the drum) which is going to mean it needs a lot of power.

I've also got a bit of a problem with the main support for the front axle, marked 'A' in plan form - I can't see how that bit won't foul the wheels that make up the drums...

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More diagrams to come - but for your delectation, here is the text of the patent. I've edited it slightly just to omit the formal presentiments at start and finish etc.
http://www.aditnow.co.uk/documents/personal-album-54/Tunnelerpatent2.pdf 

Graham

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Many thanks GrahamI- fascinating stuff!

the patent quotes the preferable power source is a small turbine (water), surely this is a bit of an understatement as the machine and power train must be immensely heavy, not to mention actually cutting through the slate... 😮

Curiously there was a turbine at MaenOfferen just behind the "old Mill" which abutted the northern hillside....

The whole business is most curious, especially when you consider the location of "cooke's level" which was driven by a twin (at least) headed machine. In 1866 there was no level, and the short north-south tunnel which one used to go through (Marked on an 1866 map as "Old Lord's Tunnel") simply ended in mid air at the quarry face. Getting the machine there at all must have been ost interesting... there's a bit more room in the upper quarry but not much.

Anyway, for those who can't get enough, here are the rest of the drawings, as well as a couple of the original 1864 machine and "the" tool.

Trepanning tunneler 1864 - Full size of tool and scale of cutting segment
🔗Personal-Album-54-Image-017[linkphoto]Personal-Album-54-Image-017[/linkphoto][/link]

Trepanning Tunneler 1864 - Side view
🔗Personal-Album-54-Image-018[linkphoto]Personal-Album-54-Image-018[/linkphoto][/link]

Trepanning tunneler 1864 - End view
🔗Personal-Album-54-Image-019[linkphoto]Personal-Album-54-Image-019[/linkphoto][/link]

Trepanning Tunneler 1864 - End view on cutters
🔗Personal-Album-54-Image-020[linkphoto]Personal-Album-54-Image-020[/linkphoto][/link]

1866 Tunneler - rest of drawings (you've got 1 & 2)
Figs 3 & 4
🔗Personal-Album-54-Image-028[linkphoto]Personal-Album-54-Image-028[/linkphoto][/link]
Fig 5
🔗Personal-Album-54-Image-022[linkphoto]Personal-Album-54-Image-022[/linkphoto][/link]
Fig 6
🔗Personal-Album-54-Image-021[linkphoto]Personal-Album-54-Image-021[/linkphoto][/link]
Fig 8
🔗Personal-Album-54-Image-025[linkphoto]Personal-Album-54-Image-025[/linkphoto][/link]
Figs 9 & 10
🔗Personal-Album-54-Image-024[linkphoto]Personal-Album-54-Image-024[/linkphoto][/link]
Fig. 11
🔗Personal-Album-54-Image-023[linkphoto]Personal-Album-54-Image-023[/linkphoto][/link]

Don't ask where fig 7 is -I can't find my original copy at the moment!
Graham

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Curiously there was a turbine at MaenOfferen just behind the "old Mill" which abutted the northern hillside....

The whole business is most curious, especially when you consider the location of "cooke's level" which was driven by a twin (at least) headed machine. In 1866 there was no level, and the short north-south tunnel which one used to go through (Marked on an 1866 map as "Old Lord's Tunnel") simply ended in mid air at the quarry face. Getting the machine there at all must have been ost interesting... there's a bit more room in the upper quarry but not much.

Graham

Fascinating drawings Graham! I had the same trouble as Vanoord trying to work out the shape of the tunnel that would result from the second machine!

What period was the turbine behind the Old Mills? Would it be possible to scan the section of the 1866 map please? Is it an OS map?

For a start here is the 1866 plan of Bowydd. I added the colour and the shape of the upper Tips from a slightly later plan - I doubt I have introduced any errors in that, as they were long abandoned even then.

🔗Personal-Album-54-Image-029[linkphoto]Personal-Album-54-Image-029[/linkphoto][/link]

Graham

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And here is part of Brunton's plan of 1877, which extended from the "Lower Works" (the old Votty & Bowydd Mill which had been leased) to the "Upper Works." This is in haste as I've not finished playinbg with it at all yet, but you'll get the idea.

🔗Personal-Album-54-Image-030[linkphoto]Personal-Album-54-Image-030[/linkphoto][/link]

That's all for now.

Graham

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Thanks Graham

Two fascinating maps! Interesting as well to see what was eventaully buried by the huge MO tip. I wonder if any of it will reappear as time goes on, now they are starting to crush that tip?

Thank you very much for all of that. How very interesting! I've seen that picture of a Hunter saw before and did wonder what the "tails" on the teeth were about. It's going to take some time for me to assimilate all this info! Was water used as a lubricant/cooler/dust reducer?

Given the data on the Hunter saw, am I correct in my calculation that the blade ran at approx. 4rpm? With approx. 30 - 32 teeth on the blade and feeding at 4"/minute this must have been "something else again"! I now appreciate why there is a length of chain around the block to be cut!
Is there an extant Hunter saw blade or at least a tooth?
What alloy steels were available in 1866? Was tungsten in use by then? The secret to all of this, seems to me, to be the teeth, without which each machine is a waste of time.