How do I build a 12' rope bridge?

Hi,

Here’s a short guide:

Where To Build The best place to build the bridge is on flat ground between 2 anchors (trees) about 20 metres (60 feet) apart.

Step 1 - Build the 2 trestles Lay out 2 sets of spars and lash the spars together with a square lashing where they cross. (Note: Ensure the lashing at the crossing point of the longest spars is done well.)

Step 2 - Lay out the long ropes

* Attach the footrope and the 2 handrail ropes to one of the anchors with "round turn two half hitches". (note: If your handrail rope is a single length then loop the rope around the anchor twice to prevent slipping)
* String the ropes out on the ground to the next anchor. 
* Attach the block and tackle to the second anchor and stretch it out towards the first anchor. 
* At the point that the end of the block and tackle meets the footrope, tie a loop in the footrope using a bowline (if the end is handy) or a figure 8 1/2. DO NOT use an over hand knot to create a loop. You will have a great deal of trouble releasing the knot afterwards.
* Attach the block and tackle to the footrope

Step 3 - Attach the first trestles

* Lay 1 trestle under the long ropes so that the top of the trestle is about 3m (10ft) from the 1st anchor and the bottom of the trestle is pointing at the anchor. 
* Attach the handrails to the tops of the long spars with clove hitches. 
* Lift the top of the trestle and position the bottom such that the trestle is leaning away from the anchor at about 45 degrees. 
* If the two handrails are not taking up equal tension adjust the length by slipping the clove hitch.

Step 4 - Attaching the second trestle

* Slip the second trestle under the 3 long ropes so that the top of the trestle is about 10m from the 1st trestle, and the base is pointing at the 1st trestle. (Note: The top of the second trestle should not be within 1.5m (5ft) of the point the block and tackle and the footrope are attached. Shorten the distance between the two trestles if necessary)
* Tie the handrails to the top of the 2nd trestle with clove hitches.
* Lift the top of the trestle and swing the bottom in until the trestle leans against the handrails at a 45-degree angle. 
* The two handrails should be parallel with the same amount of sag. If not then adjust them by slipping the clove hitch at the second trestle.

*  Tilt the 2nd trestle so that it is leaning away from the anchor and towards the other trestle.
* Adjust the tension in the handrails so that they are reachable from the ground the entire length between the trestles but clear the ground by about 1.5m (5ft) half way between.

*  Tension the footrope with the block and tackle so that it runs parallel to the handrails
* Equally space the stringer ropes (~1 metre - 3ft apart) the entire length between the trestles and attach them by tying a "round turn two half hitches" to the handrail and a "clove hitch" to the footrope. (Note: Ensure that the "round turn two half hitches" are tied at the very end of the rope and that the "clove hitch" is tied at the centre.)

Then, make sure to tension the footrope and test it for safety!