DIY Pitch Platform.

[The Old Ruminator]

Took some photos of our work this week. Thought they might help anyone else with a similiar idea.

First build your frame. The fact that this is rift makes it easier. The cross piece goes in first. To make it secure we sit this on galvanized steel pins in the wall. Sheep hurdle securing pins are ideal for this. Obviously to sit the cross piece on both pins you need to be able to adjust the pole length. We have use an acro prop with the foot cut off, then a scaffold pole inserted with a clamp on as a stop. You can then fit the entire thing tightly over the pins. Failing that you need to use two poles clamped together.

The long side poles can then be clamped to the cross piece and the boards fitted.

Cutting the boards for a snug fit. Note the second cross piece fitted to brace the frame. This can also be pinned if necessary.

Tying down the boards with industrial cable ties.

Nearly there.

Here is one we made earlier with the cross piece split and clamped. Only part of the frame needed boarding out.

Both are in Reservoir Hole where there is a loose traverse between two ladder pitches. In both cases the idea was to move the ladder out and away from the rock face.

Yes. I know. All very silly but great fun.

 

[nickwilliams]

You can then fit the entire thing tightly over the pins. Failing that you need to use two poles clamped together.

It does not need to be tight on the pins when fitted.

We use 15mm re-bar as pins and make the scaffold pole about an inch shorter than the gap it's intended to fit in. You then put the pin for the first end in the wall and put the pin for the other end inside the pole at the opposite end. Then put the first pole end over the first pin, line the second end up with the second hole and work the pin out of the pole and into place in the wall with your fingers in the 1in gap. You can use a pair of long pliers if your fingers aren't too grippy/nimble. You then end up with a pole loose on the pins, but by the time you have got the clips tight between the pinned pole and the other pieces, the frame as a whole will be tight even if individual poles are loose when you fit them.

Nick.

 

[pete h]

Mr Williams
What stops the pin pushed in with your fingers from sliding back out with vibration, might be unlikley but a possibility.

 

[nickwilliams]

Evening your dwarfness...

In theory the answer is 'nothing' but in practice it does not seem to be a problem. The pins are a reasonably close fit in the hole, and the holes can be positioned and drilled so that gravity and/or the loading on the pin keeps it in place. When the clips holding the poles together are tightened the poles tend to tighten onto the pins so that they don't move.

I must have done this several hundred times over the years, and pins coming out has never been a problem.

Nick.

 

[mikem]

I guess the weight of the platform levers the pins downwards causing them to wedge in the holes, much as modern bolts work by having the load point slightly off centre.

Mike

 

[cap n chris]

There's anchors, rope and harness on view in the photos; if there was a traverse line taking cavers away from the loose stuff, wouldn't that make everything else superfluous?

 

[ChrisJC]

Seems a lot of effort when SRT would do?

Chris.

 

[Nigel]

Just what I said! Sadly I was out voted.

 

[Aubrey]

The proper Mendip digging method is to stick the rocks togeather with cement. 

 

[nickwilliams]

Actually, as I understand it, the complete process is to split them apart before then sticking them back together.

Nick.

 

[The Old Ruminator]

Ummm. Nigel you traitor. :chair:

The point is whatever happens the ladder or SRT rope needed to be hung much further out in the rift. The ledge and points below have big loose boulders. Also the pitch is split at this point and the platform makes a perfect lifelining position. As yet we dont know if more gear has to come up here to possible digs beyond. You havn't heard about the roof and patio area yet.

 

[aquamole jim]

All you need now is a shead on it