Drilling a 120mm dia hole ...

[ColeyS1]

Anyone else wondering what it's for?

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[Sheffield Tony]

How good an edge do you think a post hole auger can take ?

 

[Trevanion]

Anyone else wondering what it's for?

It’s a Roman cannon for keeping the Celts at bay, of course.

 

[AndyT]

I find this an interesting question. We now have no normally available method to do this, because the economic need to make long holes down tree trunks has disappeared. The Romans certainly did bore out trees to make water pumps. Roger Ulrich in 'Roman Woodwork' illustrates some alder logs from Vindolanda, 750mm long, diameter 250mm, with a 65mm hole bored through. He says they used a series of augers of increasing size to make them. Pipes like this - often in elm - continued to be used until the nineteenth century and a bit longer where they were vertical pipes down a well shaft with a wooden pump fitted at the top. I'm pretty sure the Museum of London has some on display.

There's a really good chapter in Walter Rose's 'The Village Carpenter' (1937) where he describes what was a very old fashioned procedure by then, boring new pipes. He says the men who did it preferred a conical style of auger which ran true in the end grain. Each boring was about a day's work for two men and they worked through a succession of larger and larger sizes, ending up at about 5 inches... or quite near to 120mm.

I've seen a set of these augers at a David Stanley sale, where I think I am right in saying the late lamented Richard Tomes bought them. Sadly we never got to see his own brand of historical re-enactment at this task.

I hope your project comes off, Roger.

 

[RogerS]

Anyone else wondering what it's for?

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I'm trying to find out!

 

[RogerS]

I find this an interesting question. We now have no normally available method to do this, because the economic need to make long holes down tree trunks has disappeared. The Romans certainly did bore out trees to make water pumps. Roger Ulrich in 'Roman Woodwork' illustrates some alder logs from Vindolanda, 750mm long, diameter 250mm, with a 65mm hole bored through. He says they used a series of augers of increasing size to make them. Pipes like this - often in elm - continued to be used until the nineteenth century and a bit longer where they were vertical pipes down a well shaft with a wooden pump fitted at the top. I'm pretty sure the Museum of London has some on display.

There's a really good chapter in Walter Rose's 'The Village Carpenter' (1937) where he describes what was a very old fashioned procedure by then, boring new pipes. He says the men who did it preferred a conical style of auger which ran true in the end grain. Each boring was about a day's work for two men and they worked through a succession of larger and larger sizes, ending up at about 5 inches... or quite near to 120mm.

I've seen a set of these augers at a David Stanley sale, where I think I am right in saying the late lamented Richard Tomes bought them. Sadly we never got to see his own brand of historical re-enactment at this task.

I hope your project comes off, Roger.

That's really fascinating, Andy, thanks especially the reference to Vindolanda ....gives me the prod to get off my backside and go and see some of the Wall.

 

[AndyT]

Indeed! Though I gather it might be a bit brisk up there at the moment.

https://www.vindolanda.com/blog/wonderful-water-pipes

 

[Phil Pascoe]

That makes sense. Once the first hole is through, dependent on the design of the auger you'd be working into the long grain of the side of the existing hole rather than the end grain you'd be working with a large auger from scratch. The wood would probably be green as well, which would be easier to cut. A bit like the reverse of a pencil sharpener? They would justify the manufacture of the necesary tools because they probably did the same job regularly.

 

[AndyT]

Exactly that Phil. Freshly cut green wood and an old set of augers in a special bit of sacking. Have you not got the Walter Rose book? I think you'd like it.

 

[RogerS]

Anyone else wondering what it's for?

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It's for better delineating the site for the uprights of the walls for a Dark Ages fort up at Birdoswald. There are already some metal posts concreted in position but the feeling is something a bit more in keeping to reflect and emphasise that these were timber uprights.

 

[AndyT]

That sounds like an open and shut case for splitting the logs and hollowing out by whichever method you prefer then gluing back together. The hole doesn't even need to be round; two long cuts with a circular saw on a bevel cut should let you make a long square-section hole which would be fine.

 

[RogerS]

That's a much better idea. KISS ! I'm seeing my mate tomorrow and I'll discuss it with him then.

 

[RogerS]

Just thinking this through a bit more. If the larch is still relatively green then how are we going to secure the two halves together? Does epoxy stick on green wood ?

 

[Sgian Dubh]

Does epoxy stick on green wood ?

No, not as far as I know, but polyurethane adhesives will. It's the only common form of wood adhesive that I'm aware of that will stick wet wood, with wet, by definition being wood with a moisture content greater than 20%, and dry therefore being a moisture content of ~19.5%, and lower.

Of course, there may be other adhesives that do work with wet wood, but if that's the case someone else will have to come along and tell us what it is. (Hint. I'd like to know anyway if someone does know, ha, ha.) Slainte.

 

[RogerS]

That sounds like an open and shut case for splitting the logs and hollowing out by whichever method you prefer then gluing back together. The hole doesn't even need to be round; two long cuts with a circular saw on a bevel cut should let you make a long square-section hole which would be fine.

I don't think a circular saw has enough depth to get the size of circle (after a quick sketchup)

 

[AndyT]

Ah... Adze and gutter plane it is then! I'd pop round and help, but it's a bit too far, sorry.

 

[Sheffield Tony]

Superglue works very well on green wood, but you'd need quite a lot of tubes !

 

[Trevanion]

There's a really good chapter in Walter Rose's 'The Village Carpenter' (1937) where he describes what was a very old fashioned procedure by then, boring new pipes. He says the men who did it preferred a conical style of auger which ran true in the end grain. Each boring was about a day's work for two men and they worked through a succession of larger and larger sizes, ending up at about 5 inches... or quite near to 120mm.

That must've been some seriously hard graft, some of these wood pipe water systems were hundreds of metres in length and it would have taken a veeeeeery long time to bore all the pipes out!

They'd probably still be quicker at laying a line than it would take just to get through the planning stages today though! :lol:

 

[toolsntat]

It's been an ambitious quest of mine to add this pipe making process and tools to my displays, sometime.....
After talking about the aforementioned quest, I do have an open invitation to visit a local farmer with a purpose built preservation pool containing some of these original pipes. Summat else I've not gotten around to :roll:
Cheers Andy