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October 28, 2016

Suspended Tensegrity Cube by 1st Halfway House Scouts

Photo courtesy Shane Anderson
1st Halfway House, a Scout troop in Midrand, South Africa, recently built this tensegrity cube suspended between A-frames. The cube is supsended at 4 points- two underneath, and two at the top of the structure.
Photos courtesy Shane Anderson

Shane Anderson, ATS at 1st Halfway House, says:

The planned outcome of the project was to build and suspend a 10Ft Tensegrity cube between 2 x 15Ft A-Frames, (Bottom Support) and stabilised on the top by 2 x 20Ft A-Frames.

The project got of to a good start with the initial idea of building and stabilizing the cube with gadget sticks (staves) before adding the tensioning ropes, however that soon fell apart as the cube was being tensioned as the gadget sticks broke under the strain. Liam and his team then reverted to plan B, which was to stabilize with 6Ft pioneering poles.

The A-Frames where constructed by the Junior Scouts and when all was in place the cube was lifted using the 15Ft A-Frames and 2 x block and tackles while being kept upright by guy ropes.

If you look in the cosntruction photo above, you'll see the 'jig' of light lathes that was used to hold the cub in place while it was built. As Shane says, it's a good idea, but you'll need to use heavier poles to handle the strain.

Photo courtesy Shane Anderson
Here's the model used to plan for this project. Models are really useful tools for pioneering, because they help you plan the project, picking up some problems before building at 1:1 scale.

Congratulations to Liam and his team for building this structure!
Photo courtesy Shane Anderson
Congratulations to Liam and his team for building this structure!

October 7, 2016

56m suspension bridge at Manjedal Activity Centre, Western Australia

Greg from West Australian Scout Pioneering wrote in with photos and a description of the awesome bridge, supported by A frames on each end and a raft in the centre. Here's Gregs description:

Photo courtesy Greg Barbera

Project : Build a Rope bridge for the West Australian Cub Scout event – Enduro 
Location: Manjedal Activities Centre (M.A.C) – Lake Jones 
Depth: Varies from 4 meters to 15 meters Span: 56 m (40m over water) 
Water Temp: Very cold 
Weather: everything except snow 
Duration: 16 hrs to build
Photos courtesy Greg Barbera

To help celebrate the 100th Anniversary of Cubs, the Organizing team decided to go with a “Back to the Future” theme. They also want to surprise the cubs by having an activity based around the traditional methods of pioneering that have been with the movement for over 100yrs. The West Australian Scout Pioneering Crew (WASP) were asked to build a bridge across Lake Jones that would be sturdy enough to withstand a very large number of Cubs and Leaders using it.
Over the two days of Enduro approximately 800 Cubs and a small number of leaders made the crossing. To ensure the build met the requirements of pioneering in Australia, the walk rope was set at a height of 1.8m from the ground so that helmet & harness would not be required (anything over 2m). This meant that we had to install some form of support in the middle of the arc to keep the ropes & cubs out of the water. Several suggestions where made of a tower, but owing to the erratic shape of the bottom of the lake there would be no guarantee that a level section could be found. It was decided that a pontoon would work providing it could be securely moored and be able to support the bridge as it pass over it. It was decided that a 4m x 4 m pontoon made out 100mm dia. pine logs with 4 x 200ltr blue plastic drums and 6 x 140ltr white drums would both support it and stabilize the middle section. In addition 2 vertical poles where fitted so the bridge ropes could be attached to the pontoon using Carabiners, this would still allow the ropes to be tensioned without moving the pontoon from its moored position. 
We also fitted an arrival and departure deck which only covered the area under the bridge, a walkway was also fitted for a leader to use to assist those passing through the middle section. On the trial build of the pontoon we fitted guy ropes to the vertical posts but found that caused problems and a trip hazard for the leader, so this time we used 3 spars on each vertical and lashed them in place, to reduce the amount of rope required we made the first lashing a figure 8 and pulled the side poles out to create the angle brace. Then fitted one on the outside and lashed a horizontal spar in place so the walk rope could also be clipped onto the pontoon. For this span we fitted each line with 2:2 rope block combination and used the pontoon as a means to keep the lines tensioned as the combined weight totalled approx 350 kg. The main ropes where 20mm dia. sisal and to assist the hand rails to support the walk rope we fitted short lengths of rope which we refer to as stringers. Normally when we fit pulleys on to the main ropes to take up the tension, we used the prussic loop to attach the block, for this one we used the “Dog & Tail hitch”. This hitch does the job well and is easier to move when it is not under load. 
On the shore we used “A” frame assemblies that are self supported by guy ropes and thus allowed the main ropes to be tensioned freely. Carabiners were also tied to the frames to support the hand lines. To stop the main line travelling along the horizontal bar, we used a short length or rope and tied a clove hitch on both sides. Normally we would use a log & picket anchorage for our rope bridges, but in this case the ground on both sides was too soft to get a good footing. On one side the soil was too moist and on the other side there was a very large ant hill, which meant we had to contend with hollow ground owing to the nest. We therefore bound the trees with hessian to reduce any damage to them. 
To reduce the risk of the Cubs endangering themselves if they fell off, each person making the crossing was required to wear a life jacket and we had a rescue craft on standby (canoe). Out of the 800 cubs only 2 ended up in the water and 7 were rescued by the safety vessel as they held onto the hand rails.

September 23, 2016

Two-tent raft in Malta

 Sean from Mosta Scout Group in Malta shared these photographs with me- of a raft sitting in this stunning location against the cliffs in the Mediterranean.

Sean says:

"With 100 lashings, 40 staves, 30 barrels and 10 Marine Ply, a massive Double Floating Raft Camp served as our home for the past weekend. This is just a glimpse, from what Scouting is all about 😉"

(previously- pioneering from Mosta Venture Crew)

September 16, 2016

Ropes and Pole badges - selected design

 Thanks to everyone who voted in my earlier poll to help me choose a badge design for the blog. As you can see below, the Hy-par pavilion was by far the most popular design. I have sent the badge off for quotes and will have news soon about where and how you can purchase the badge. Thanks for participating!

September 9, 2016

Bamboo arches in Ghana- Haduwa Arts + Culture Institute

Photograph copyright Baerbel Mueller

This bamboo stage pavilion was built for The Haduwa Arts and Culture Institute in Ghana by [applied] Foreign Affairs, an architecture lab at the University of Applied Arts in Vienna. A group of students built the project as part of their architecture classes, after researching the project in Austria and on site in Ghana.

Normally, when we build pioneered structures for Scouting, we use the bamboo the way we would any other pole- as a rigid, straight pole. This structure makes great use of the flexibility of bamboo to curve the arches, and also uses the idea of 'bundling' smaller poles together to make larger arches. While this structure might be much bigger than the normal Scout projects, there is an opportunity to learn from the way the students worked with bamboo in this project.
Construction details. All photographs copyright Baerbel Mueller

Project credits:
Client: Haduwa Arts and Culture Institute architecture and concept [Applied] Foreign Affairs, Department of Architecture, University of Applied Arts Vienna
Project Leader: Baerbel Mueller
Project Team: Christian Car, Joseph Hofmarcher, Ilias Klis, Joana Lazarova, Ewa Lenart, Ioana Petkova, Philipp Reinberg, with Antonella Amesberger, Clelia Baumgartner, Stephan Guhs, Frida Robles, Andrea axis
Guest lecturers - bamboo construction: Jörg Stamm, Construction: Franz Sam, Structural: Klaus Bollinger, roof: Manora Auersperg, Christoph Kaltenbrunner, Performance Arts: Daniel Aschwanden

More information:
Designboom article
Architektur journal (Deutsch with English translation)

September 2, 2016

Vote for a Ropes and Poles badge design

I've been contemplating having badges made, which would be available for sale here on the blog. Some designs are shown above, featuring various projects from the blog archives, and I'd like your help choosing the first one to have embroidered. Please scroll down and vote below, or click on this link to go to the poll. Thanks!


August 26, 2016

Suspension Bridge from Feb 1937 Scouter magazine

I found this suspension bridge article written by L.C. Sands in the February 1937 Scouter magazine:

No special credit is claimed for having succeeded in building the bridge described here, as it involves a principle in common use, but as the writer has not seen anything similar described in any of the books on pioneering, he considers that other Scouters might possibly like to try it out, and doubtless improve upon it. Its chief advantages are that it needs only simple materials, is easy to construct, and is one which could be crossed with ease by many people who might hesitate to venture on a monkey bridge. Any measurements stated here may be altered to suit local conditions.

Two Towers were constructed of four spars about 9 ft. long, with 1 1/2–2 in. butts, and seven Scout staves 5 ft-long. First the side trestles were made by lashing two spars together as near the top as possible with a sheer lashing, and then the ledger was put on with square lashings about oft-from the bottom of the spars. These two trestles were then connected together to form the tower by lashing a strong pole across the top in the V’s made by each pair of spars, and by lashing poles adjacent to or slightly above the ledgers of the original treetles. The base of the finished tower was about 4 ft. square. About 2 ft. from the ground further poles were lashed to both back and front of the tower: the one (A in the diagram) nearest the bridge proper bore the two hawsers of the roadway, while both bore the planking.

The Roadway was made with two 2 in. ropes to which were attached twelve Scout staves at intervals of about 1 yd., by means of lever hitches a few inches from the ends of the staves. This method is probably not the best for strength, but it is quick, although about 1 ft. of the rope is used up in making each lever hitch. When this is swung into position, the ropes at one end should pass over the front pole (A) on the tower, under the back one (B), and be made fast to pickets or some convenient tree if available. The other ends should be similarly secured, but if possible block and tackle should be used to tighten them at one end, as was used in this case.

Suspension lines were made from 1 in. cord throughout, twelve in all three for each side of each half of the bridge. These lines were attached to the pole forming the road-bearers of the bridge, and to passed over the top pole of their respective towers to pickets or suitable trees. In the case of the lines attached to the two centre poles (E and F.)loops should be made in the cords about 2 feet from the ends fastened to the roadbearers. The two loops in these two lines from E and F (see diagram) were then drawn towards one another by another cord until the angles between the roadway and the portions of the cords below the loops were almost right angles, and then made fast. This other cord was then continued in either direction, taking a turn round each of the suspension lines in passing to the towers, to form a handrail. The reason for so dealing with the middle suspension cords was to increase the angle between the suspension lines and the roadway, so as to get a better suspension of the centre part of the bridge This proved the most satisfactory of several methods tried.

The other cords from C. D. G. and H go straight from these points over the top poles of the towers to their respective pickets. These suspension cords should all be fastened on to the roadbearers at D, E, F, G and H before the suspension part of the bridge is swung into position across the gap to be bridged. All that then remains to be done is to pass the cords over the top bars of the towers and fasten to the pickets. Before use the suspension cords should be adjusted so that the centre of the bridge is slightly higher the the ends. This method of suspension was found to be the most satisfactory and easiest to make as any particular cord can be readily tightened up. Of course extra strength would be gained by adding similar cords to some - the other road-bearers, e.g., those between C-10, and G. H.

To complete the bridge some form of planking should be laid across the road-bearers and lashed to them. In this case, some fifteen inches (in width) of planking put on for the whole length, and this in itself was a considerable weight. The length of the actual bridge between the towers was 38 ft.

This bridge proved very satisfactory in practice. After it had been used a number of times the drop in the centre, while an average-sized adult was standing on it in the middle, was only 9 in, and it may be added that the writer rode his bicycle across it.