DISCO DAVES TUNNEL GUIDE
Lock ons
Like the hand grenade the inventor of the lock on is unknown. They are easy to make and can be put almost anywhere. A good one can be a real pain in the arse for Mr jolly bailiff
How to make a lock on
A) Find a piece of plastic drainpipe that your arm will fit into snugly with a thick jumper on. The pipe should be long enough to cover from just above the elbows to around 4 inches further from where the hand is at the other end. Estimate where the hand is inside the pipe then mark the pipe on the outside. Everyone's arm length is different. A lock on designed for a long armed man will be impossible for a smaller person. So try to make a standard length with one size fitting all. (If no drainpipe is available two litre cider bottles with the tops and bottoms cut off then fixed together work almost as well).
(B) You'll need a steel bar or similar that's around 2 feet long. Start a fire then heat the end of the bar until its red hot. Put a thick glove on then drive the bar though the pipe where the mark is. Then put the pipe under a cold tap. There is generally little point in making a fire and using up valuable wood ,to heat up one lock on bar. When with a bit of fore thought a lock on production line can be put into operation making five to ten at a go.
Try to put the bar through the end of the pipe which is rough edged after it's cut to size, leaving the smooth end for the persons arm for comfort. The overlong bar will hold the lock on more firmly in place once the concrete has been poured.
(C) To actually lock your hand on to the metal bar, You'll require a lock on clip.(either a climbers clip or a gun clip) Cut a piece of small chain just under a foot long and wear like a bracelet around your wrist.
(D) Use a nut and bolt to join the chain
(E) To provide comfort feed the chain through part of an old bicycle inner tube.
(F) Attach either a gun clip or a climbing clip to the chain to join the ends
(G) Put the bracelet on and grip the clip with the thumb and first finger. Then insert the hand into the drainpipe and clip on, then off the bar.
Once made and ready for positioning and covering in concrete one of the most important parts of lock on building yet probably the most ignored should be considered:comfort. It's all well and good making a lock on out of reinforced steel surrounded by tonnes of concrete but a nightmare for the person who will have to occupy it when it's positioned vertically in the floor of the tunnel forcing the person who wants to use it to lie down and remain with an arm rapidly turning blue down a tube, unable to unlock themselves. This scenario for the locked on person in the Shovel and Bucket tunnel in Birmingham very nearly caused them to loose their hand- an extreme example of what not to build. If the lock on is a well made one and the person occupying is an obstinate beast it will take hours, even days for the Bailiffs to cut them out. That will only happen though if the angle of the lock on tube is shallow enough (ie 40 degrees) to allow blood to pump back up the arm. If the angle is any steeper then really you're wasting your time and valuable concrete mix. Of course there's no harm making "quickie" lock ons with outrageous arm numbing angles if there's little concrete and time used on them. These will be easy for the bailiff to evict, even if they aren't evicted immediately the occupier won't feel guilty about giving up a defence that's only taken a couple of hours to throw together, rather than a few days. For both the "quickie" and "long haul " lock on tubes put a lot of tape around the end of the tube to prevent an arm getting too sore.
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