5. WOOD AND WIRE LADDERS

When lightweight metal ladders were first put into service a few club members complained that when climbing these after a strenuous wet cave, the aluminium rungs caused cramp in their hands.  This was no doubt due to the high thermal conductivity of the metal, so several lengths of ladder were made using wire rope and wooden rungs.  An experimental ten feet length was first built and when this proved satisfactory, a further fifty feet were made.  These were not replaced when they wore worn out as the original complaints had ceased, probably due to the fact that in St. Cuthbert's Swallet, the scene of much of the club's activities for the last few years, the pitches had been fitted with rigid metal ladders.

The general design can be seen from figure 11.  The main consideration was to make them as simple as possible using only simple hand tools.  The rungs are made of ash, 7" x 1" x 7/8" having all the corners removed, and drilled at six inch centres to take 10cwt wire rope.  They are supported on aluminium sections made by cutting 5/8" x 5/8" diameter plugs in half to form semi-cylindrical pieces, and drilled to make a sliding fit on the cable.  A short length of tinned 18swg wire was passed through the centre of the wire rope, bent parallel to the rope and soft soldered to take the weight.  A similar solder globule above the rung enabled the rung to be slid up the wire for inspection of the rope but at the same time preventing the rung from getting too far out of position. Obviously this type of ladder could only be hung from one end.

Figure 11

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