DISCO DAVE'S TUNNEL GUIDE
Erecting and constructing the shoring
In phase 4 the principal behind shoring has been outlined. The practice of cutting then erecting it in a small tunnel is usually a total nightmare no matter how often you do it. If you can dig 40 to 60 feet of uniform tunnel in all types of soil in weeks and months rather than years. Then to paraphrase Rudyard Kipling
" you'll be a tunneler my son". Well for us mere mortal women and men who find that they've dug out a tunnel with one wall higher than the other and with a slight gradient , I'll say this don't worry it's normal. Before putting in any shoring try to level off the roof as much as possible. Contrary to popular belief it is ideal but not essential to have the board above the cross beam tight up against the soil. Good shoring will hold the weight of a collapse. However the gap between the board and the soil should not be too excessive. Anything over a foot and a half could be asking for trouble and allow the soil during a collapse to gain enough momentum and knock out the shoring. You'll now need another tunneller and possibly a colleague on the surface with a saw and another tape measure. As the shoring will be supporting a board. A section of shoring must thus consist of 4 uprights, 2 cross beams 4 feet and a board above the cross beams. Where each upright is to go measure from the floor to the roof. If your near the surface you can probably go out of the tunnel and cut it yourself. But it is generally better to have a colleague who you can shout the measurements to for him or her to cut. To avoid mistakes when shouting measurements to a colleague get into the habit of asking them to shout the measurement back to you. Or you may end up with an upright that is two feet longer or worse shorter than you need.
Before shouting for the upright to be cut remember that above the upright will be a cross beam and a board below the upright a foot. For example
The tunnel height on the left side is 4 feet The board is half inch thick. The cross beam is three inches thick. The foot is half inch thick.
The upright should thus be 3 feet 8 and half inches tall. It's worth however cutting the upright to a length 3 foot 11 inches. Eight and a half inches may fit but it won't be a snug tight fit as will be explained later.
(C) Measure and cut the remaining 3 uprights with an extra 1 to 2 inches on each.
(D) Measure and cut the crossbeams feet and boards.
(E) Patience,persistence and a sense of humour are essential prerequisites for tunnellers about to install shoring. Level off the floor,then using a spirit level place a foot where an upright is to go.
(F)Lying on his or her back the tunneller should hold the board up tight as possible against the roof
(G)In front or behind this lying tunneller with timber to hand and being careful not to accidentally hit them. The second tunneler should hold a cross beam up against the board which is grabbed by and held in place by the first tunneller(1)
The second tunneller should then position an upright over the foot(2)
then bang it into place until it's vertical (3)
(H)Position the upright on the other side and bang into place. The extra 1 to 2 inches on the upright should mean the shoring is tight against the roof. If not remove and chop out soil from the floor a little at a time.
(I) The person lying down should now be free to get up and assist his or her colleague shoring the other end of the board. Do exactly the same as before and after a few arguments and about 4 or 5 attempts the first bit of shoring is completed.
(J)Make sure the uprights are upright use a spirit level and club hammer to knock them until vertical.
(K)With the roof board up tight against the soil and the shoring vertical use 5 inch nails to nail the upright to the feet and to the cross beams.
*Having more than two people erect shoring is a mistake. In such a confined space you'll get on each others nerves. Whats more it's always better to work with someone you know and get along with.
*This is particularly true in a Tight and nasty tunnel. For a doored and shored tunnel however room should allow for an extra person.
MIB (Men in Black) Shoring
As mentioned earlier shoring does not need to be tight up against the roof of a tunnel providing of course the shoring is of a good standard. The MIB (who are specialists sworn in as bailiffs to evict the tunnels) construct their shoring to meet with health and safety requirements. You can of course copy their ultra safe shoring which would mean though that you would be doing a lot of work for them thus speeding up your own eviction.
The distinct flaw with most protester shoring is that protesters presume that a tunnel collapse will only happen from above and they thus make their shoring to deal with such an eventuality. Collapses however aren't so and could come from the side as well as the top .
(1)The MIB begin by levelling off the ground then place a piece of two by six timber.
(2)They then cut a board to go above the cross beam as well as cutting the cross beam .
(3) The MIB generally construct their shoring so it will allow two men (ie normal bailiffs not MIB's ) to come down the tunnel and pull out a protester if they refuse to come out of the tunnel when the MIB have reached them. Their shoring is thus generally made so it is at least 23 inches wide. During the Arthurs wood eviction at Manchester in 1999. The MIB knew the protester at the end of the tunnel as they had dug him out two times before. They therefore presumed (rightly as it turned out) that he would not resist and gambled by making a tunnel that was just wider than the existing protester tunnel. Though this allowed them to make faster progress the tunnel held out for 22 days before it collapsed. Though fortunately this happened 15 minutes after the protester had left the tunnel. To what ever size the MIB construct their shoring, after they have put in the 2"by 6" piece of timber on the ground they then place a small acro bar on the floor beam and tighten the crossbeam up against the ceiling.
(4) once the cross beam is in place side boards are cut to go behind the uprights which are then knocked vertical. The acro bar is then removed .
They then place what they refer to as a " kicker" in between the two uprights. Two up rights and a cross beam alone will not stop a collapse from the side. The Kicker placed tightly and nailed below the crossbeam will prevent the shoring merely falling to one side. Everything is then nailed into place.
Phase 2 Shoring the down shaft
Phase 5 Constructing and erecting shoring
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