On the next page's we are going to look at constructing some pioneering projects, starting first with something simple and then getting a little more complicated.
First you must construct an A frame. We use A frames for a number of pioneering constructions and usually you will need two mirroring each other. You must take great care when constructing two as they must be the same in height and width, with the part where they cross over at the top in the same place, and the cross bars at the same height. if in doubt make one and then place the other on top of it, another thing to consider is were the sheer lashing is going at the top to make the crossover, because depending what you are making will determine where you put this, but for now concentrate more on just making a small A frame. once you have made it get some help to hold it up and test your lashings by standing on the cross bar, you can use it as a chariot by standing or sitting on the crossbar and have two or more friends pull it round, as in C and D. Something larger can be used to help you cross a stream or small river, as in the demonstration A and B, by standing on the cross frame with help you can use the frame as a pivot and cross from one side to another, fasten a rope to the top with equal lengths on both sides to assist you, a long pole can be used also on each side to help with the pushing but great care must be taken when lifting, pulling, and lowering the frame on the apposing sides. A chariot race is much more fun, but you need two people to hold it up at the sheer lashing when in use, try a couple of short runs first. Remember think safe, and always use the safe lifting code, bend at the knees, keep your back straight, and keep the weight close to you're body, and never lift more than you are comfortable with.
Now lets try something bigger? a commando bridge using A fames, usually this type of bridge runs between two trees on apposing sides of a river, or ditch, but this is not always convenient.
We start by considering what we will need to make two A frames. Six lengths of rope for the lashings, four longer spars/poles of equal length, and two smaller ones for the cross members. two long lengths of rope, and how long will depend on the length of bridge you want to make, one to stand on, and one to hold on to taking into consideration that the bottom rope will need to hold the weight, and more, of the heaviest person to cross, if in doubt ask your supplier what load the rope is capable of holding before it will snap. You will need a minimum of four metal pegs, but eight would be better, these need to be suitable to hold up the A frames and to take the strain of the two ropes. We use metal spikes/pegs specially made for us by a local blacksmith, these are of different lengths and diameter, I pick ones to match what we are building, and the condition of the ground on site. you will also need a block and tackle to take up the slack on the bottom rope, or you can use a drovers hitch if the distance between the A frames is not to great. you will also need four short lengths of brush handle or similar, but I will explain later, one small double pulley would also be an advantage but not essential, a sledge hammer and four people.
I am using a mix of pictures to show you what to do, so if the A frames change you know why. Above are the materials set out for the construction of a monkey bridge note the metal pegs. I always set out what we need first and inspect each item in turn. next is two A frames of equal size remember what you must do when building two A frames of equal size, and again another picture of some of the metal pegs I use. When you are happy with the A frames set them in place on site where you want them, next
remove the grass where the feet are to sit and place them in the hole, this will stop the frames from moving but keep the sods of grass safe to put back later. Next hammer a large peg in the ground at a suitable distance from the frame, get your friends to lift the frame till it stands up straight, and fasten the red rope to the peg with a round-turn and two half hitches. make sure one of them keeps holding it in place at this point, because it will still fall down. Next do the same at the other end, but this
time apply some tension to the red rope with either a drovers hitch, or a block and tackle, which you use is up to you? refer to diagram. Finally fix the bottom rope across the bottom cross bars of the A frame and attach to a double block and tackle as in the diagram and picture, and apply enough tension to keep it taut. you need to inspect the tension on the bottom rope constantly and adjust as the A frames settle and it becomes slack.
fasten/fix any top ropes to it before lifting, (for this bridge the red rope for holding onto, wrap this round the A frame as in the diagram below, and the blue to keep the frame in place) this will make things easier later on, also
In the pictures above we did not us guy lines to hold the A frames but this was only because they were made during a Patrol Leaders competition and a maximum of six people were going to cross the bridge in total, by wrapping the top rope round the A frame this is sufficient to hold up the frames, but as sated you must constantly monitor the safety of the A frames. If you are going to have the bridge up for some time and a number of people are going to cross it then for safety reasons I would use four guy lines to hold up the A frames one to the top of each spar of the A frame, and held in position with a drovers hitch. Check the tension of these lines and if they become slack adjust them, its better to alternate from one A frame to the other keeping an eye on the angel of the A frames, you do not want them to lean one way or the other precariously.
Activities involving ropes can be dangerous. Therefore If you decide to replicate any of the activities, shown and described on these pages, they must be done under the supervision of a responsible instructor. When using knots the choice of materials; the age, size, and condition of ropes; and the accuracy with which you tie them is crucial. Also using the correct knot for the job, is just as important as maintaining all your pioneering equipment in first class condition. For this reason no responsibility can be accepted for incidents arising from the use of this material.