Introduction This is a fairly straight forward tower which is strong because it consists of lots of triangles. The height depends of the length of spars available.
- 3 x spars 4.6m (15ft) minimum
- 6 x spars 2.5m (8ft)
- 6 x spars 1.8m (6ft)
- 4 x spars 1.2m (4ft)
- 32 lashings
- 3 x 10m ropes for guys
- 10 x small spars or large pegs
- 2.x 6.0m ropes
- 3 x spars 4.0m (13ft)
- 1 lashing
- 1 x 20m rope and matching pulley
- 2 x spars 2.5m (8ft)
- 1 lashing
Lash the 3 x 4.6m spars together, using a figure of eight lashing approx. two thirds of the way up from the butts.
Stand the tripod up then lash 3 of the 2.5m spars between them, using square lashings, approx. 0.5m up from the butts.
Lay the structure back on its side supported at the figure of eight by a pair of sheer legs. (Diagram A)
The remaining 2.5m spars are used as the platform supports and are held in place with square lashings. These should be approx. 0.7m below the top of the main spars. (B)
3 x 1.8m spars are used as hand rail support and are lashed to the end of a platform support and the corresponding main spar. (C)
The last 3 x 1.8m spars are then used as the handrail and lashed between the handrail supports. (D)
The 1.2m spars are used to form the actual platform.
The 3 x 10m ropes are attached to the structure just above the platform to act as guys.
Construct the rope ladder and attach it to a platform support spar.
Stand the tower up. As the structure is quite heavy, the best way to raise it is using a tripod and pulley as we did for the hour glass tower.
Peg out the guys, drive in more pegs near the feet of the tower and lash them securely.
The rope ladder is made using the marlinspike hitch.
The trick is to work from the top of the ladders and tie both ropes to the centre of each rung. The rungs need to be approx./ 0.4m (16″) apart. Once the ladder is complete the ropes are moved out to the end of the rungs. The knot part of the marlinspike hitch needs to be below the rungs. (a) If the bottom of the ladder is tied to a lower spar it can be climbed like a normal ladder.
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Note: Since the design of the project the principles of Health and Safety have changed dramatically.
Caution should be exercised to assess the risks associated with this build and especially regarding possible falls from height, so additional handrails or belays and harnesses may be required, depending on the height of the platform.