Tunnels

[Dan Wilson]

(several topics merged - GG)

I hate being asked to dowse tunnels which are only rumoured to be there. I'm in the middle of an exchange with a gentleman the previous owner of whose house said his mother remembered a flight of steps going down to a subterranean door in the garden. The church is next door. This declivity had been filled in for safety before he'd bought the house.

Archeo dowsing isn't my forte other than dating things. I had my fingers burnt when on a disused slate mine investigation in Snowdonia I boldly said that one more chamber than the 1926 plan showed was down there. If I'd thought about it I might have been more cautious as the mine closed when its longish access tunnel collapsed in 1928, and a chamber may take 20 years to be opened out fully. An exploration gang got in through a blocked adit (level tunnel) and my chamber wasn't there, though a 60-foot access tunnel to it which would have been the start, not shown on the plan, was. I'd picked up the intention only. The team leader said it just showed, dowsing was bunk.

Later I was invited to "lurk", in forum terms, on a Channel 4 Time Team dig of a "fogou" (say "foogoo"), a prehistoric underground temple or hidey-hole in Cornwall. Hamish Miller was there and declared a local legend of a tunnel to it to be based on fact. I demurred and was sidelined as a killjoy. The host's lawn was comprehensively dug up to a depth which would have revealed such a tunnel, to reveal nothing so exciting. These experiences have left me inclined to rubbish all tunnel stories, on principle.

The present job, to my displeasure, has indicated a real but badly-built 18th-century tunnel which fell in within 25 years. All the "yesses" are weak ones. I hate it ! I sketched in the route on a tracing of the OS map of the town, along with the buried steps and the original terminal structures which I said were like slab-topped graves at both ends, entered by ladder. I felt the tunnel had been built for smuggling stuff into the church crypt, which had been sealed up in 1900 or thereabouts.

Feedback from client: he is certain my steps are in the right place (how can he be when he never saw them ?), both his garden and the churchyard are chockablock with anonymous slab-topped graves, the town was a hotbed of smuggling at the time I nominated (1780) and the vicar knows of no crypt but then the church was comprehensively rebuilt starting in 1897.

I have the feeling I am unwittingly a tool in the client's rabid wish to find a tunnel. Let us hope his willpower is strong enough to generate a real one. Mine is not.

[griff]

I have recently been asked to locate tunnels on a property adjacent to a slate quarry pit which has been filled-in for landfill, most of my work is prospecting for potable water borehole sources and I am unsure about dowsing for dry cavities. I understand that in the 19th century French dowsers were successful in mapping tunnels and cavities beneath Paris.

Can anyone suggest appropriate procedures in dowsing for such a project?.

Happy and prosperous New Year to all.

Regards. Griff.

[Geoff Stuttaford]

I have recently been asked to locate tunnels on a property adjacent to a slate quarry pit which has been filled-in for landfill, most of my work is prospecting for potable water borehole sources and I am unsure about dowsing for dry cavities. I understand that in the 19th century French dowsers were successful in mapping tunnels and cavities beneath Paris.

Can anyone suggest appropriate procedures in dowsing for such a project?. Griff.

Hi Griff,

You may like to try the following :

Off Site :

1. Get hold of a map or an aerial photo of the site to be investigated on the largest scale you can find.

2. Draw a grid of one inch squares on the map or the photo.

3. Dowse each horizontal or vertical line of squares to determine in which squares the tunnels lie. (use a pendulum) Tick the relevant aquares.

4. In the squares where there are tunnels, draw another grid of squares and repeat 3 above. This will give you a fairly accurate picture of where to start your site dowsing.

On Site :

1. Using an L-rod, ask that one side of any underground tunnel or cavern be revealed to you. Start walking where the L-rod leads you.

2. Leave markers every few yards and particularly when you diverge from a straight line.

3. Follow the line indicated by the rods back to your starting point. You should then have the plan of the tunnel or cavern defined on the surface of the ground.

4. You can then measure the dimensions of the ground plan and transfer them to your map or photo, using trigonometry if necesary

5. You can ask your rods to indicate any blocks in the tunnel by getting them to turn at right angles to your line of walk, but dont forget to search beyond any block as the tunnel may continue beyond the blocked point.

Having plotted the plan of the tunnel, you can now return to off site work and, if required, plot the cross section of the tunnel at any point by using a scaled grid, using a pendulum. The depth of the tunnels, the date of construction and the location of any flooding can also be determined by dowsing.

A similar method can, of course, be used for archaeological dowsing.

Hope this helps.

Geoff

[griff]

Hi Geoff

Thanks for the advice, I will visit the site again with 'L' rods when the wind is not blowing quite as hard as on my previous visit, when I was forced to use the old hazel twig.

Will keep you posted on results.

Regards, Griff.

[SussexJim]

For those [beginner dowsers] who discover finding a 'tunnel' problematic .... have you tried dowsing over sewer man-hole covers where there are accessible hollows? [ on pavements...we dont want car-flattened dowsers]

Alternatively, if you have a good solid, victorian brick built arched bridge, the arch also reacts as a 'tunnel' or cavity, so that you may accurately measure your sensitivity to the leading edge of the hollow space.

Both methods allow for ease of checking - providing you have a man-hole cover key, of course!!!

Depthing may also be readily checked.
...however, dowse first, then measure... otherwise you may prejudice results.

[Old Bob]

Re the mistakes, I am sure certain some people who have the mind ability subconsciusly interfere with dowsers and one needs to work alone for best results. I try to only have people with me who I know don't tune in (for lack of a better way of explaining) Tunnels have been easy for me, but not little things like lost ear rings.