Banana Bridge

Equipment

• 20 x 1.8m (6ft) spars
• 5 x 2.4m (8ft) spars
• 8 x 3.0m (10ft) spars
• 4 x 4.0m (12ft) spars
• 4 x 5.0m (16ft) spars
• 68 lashing lengths
• 6 long ropes
• large tent pegs
• 4 stout pickets
• 1 maul

Method

Construct 4 pairs of sheer legs using 8 x 3m (10ft) spars and sheer lashings – two on each side of your stream or ravine.

Lean the sheer legs together in pairs to form two low pyramids

Lash the 5m (16ft) spars across the long sides of each pyramid.

Lash 2.4m (8ft) spars across the short side of each pyramid to provide stability during assembly.

Prepare a ‘trapeze’ to support the centre of the walkway by tying a lashing length to each end of the remaining 2.4m spar with a round turn and two half hitches. Tie the other end of the lashing lengths to the corners of one of the pyramids at A and B.

Tie a long rope to the corners of the pyramid next to the trapeze ropes. These will be used to raise the pyramid into position.

Ease the pyramid forward across the stream, lifting it using the long ropes and manoeuvering the corners on the ground into position. Place large pegs in the ground to prevent the corners sliding. Lift it higher then the finished structure will require and tie off the long ropes to pickets to stabilise it.

Place the other half of the bridge in line with the first, tie two long ropes to the corners and raise it, maneuvering it into position and putting in pegs around the bottom corners.

With a team of Scouts on either side, gently lower the pyramids until they interlock.

Lash the 12ft spars together to form the sides of the walkway. Lash the 1.8m (6ft) spars across these to make a ladder.

Carefully pass the ladder across the stream and through the trapeze so that either end rests on the bank.

Helpful hint

Careful measurement is required to ensure that the pyramids are the correct distance apart – this may only be resolved through trial and error. Too far apart and they will not lock but will fall down – too close and they may fall backwards.

Knock pegs into the banks and lash the ends of the ladder to them to ensure they do not slip. Finally, tie ropes between the pyramids to act as hand rails.

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 handrails or belays and harnesses may be required.

To download the complete plan and design document please Click Here