Sequential Programming: Monkey Bridge


Troop 86 from Sumter, SC wanted to do a pioneering project and they selected the Double A-Frame Monkey Bridge. Great place to start, and a great way to illustrate sequential programming. What skills enter into the picture? A whole bunch! And with each step along the way, there’s an activity wherein each campcraft skill can be put into action, in a fun way, as reinforcement.

B.-P. wrote: “I am inclined to suggest to Scouters that in addition to the technical details of knotting, lashing, and anchorages, there is an educative value in Pioneering since it gives elementary training in stresses, mensuration, etc.” In addition to the “mensuration” skills that come into play when setting out the area for the bridge’s A-frames and anchors, a good deal of measuring takes place to assure the A-frames are as close to identical as possible, the pairs are joined together in similar fashion, an the spanner ropes are spread evenly. (Hand in hand with the building, Scouts do a lot of planning.)

 tape-measure-2  tape-measure-1

—> What is Sequential Programming?

SEQUENTIALLY-PRESENTED SKILLS AND RELATED ACTIVITIES

Open-Ended Clove Hitch – How else would you want to secure the hand ropes to the A-frames? — How-to Video / Activity Video

Using Half Hitches to tie a Clove Hitch – A simple process always makes it easy to tie a clove hitch and finish many types of lashings. Several are used to attach the spanner ropes. — How-to Video / Activity Video —

Round Lashing – Three or four can be used to join together the bottoms of the A-frames on each side. Round lashings can also be used to attach a flag pole(s) to an A-frame(s). — How-to Video / Activity Video

Square Lashing – This project can use fourteen of them for both building the A-frames and then joining them together. — How-to Video / Activity Video

3-2-1 Anchor – The skill is to carefully drive in the stakes at the proper angle and applying the tourniquets to join the groupings. — Explanatory Video

Roundturn with Two Half Hitches – You can use this pioneering knot to attach the hand ropes to the anchors. — How-to Video / Activity Video —

Butterfly Knot and Rope Tackle – This configuration can be used to adjust the tension on the foot rope. — How-to Video 1, How-to Video 2 / Activity Video

—> BUILD THE BRIDGE

Anchoring Pioneering Projects II

VIEW VIDEO

Any pioneering project that cannot safely stand by itself needs to be attached to something that will securely hold it in place. It has to be anchored. Sometimes nature will provide a tree or rock in just the right location or you might be able to shift the project’s placement to take advantage of a natural anchor. On all other occasions, anchors need to be built that will assure the structure’s stability.

Stakes – When nature does not provide a solution, anchors can be built using strong pioneering stakes. The common size of stakes for most Scout Pioneering projects is 2-1/2-inches in diameter and about 24 to 30 inches long. After cutting the stake to this size, cut a point on one end. It’s good to bevel the top edge to minimize mushrooming or splitting when the stake is driven into the ground. Long-lasting pioneering stakes are made of hardwood, such as oak or hickory.

Drive the stakes into the ground at about a 20° angle. Soil conditions can vary and will dictate how large and long a stake you need. The main thing is to make sure all stakes are deep enough so they don’t wobble or budge at all.

Under no conditions should tent pegs be used for pioneering stakes. They’re neither long or strong enough to make a safe anchor.

Page52 AnchorsMallet – When driving stakes into the ground, it’s best to use a wooden mallet. Using a metal sledge hammer can more easily damage the stake. To make a wooden mallet, cut a 4-inch diameter piece of hardwood, such as hickory, elm, or sycamore, to about 11 inches length. It should weigh about four pounds. Drill a 1-1/8 inch diameter hole to mount the handle. The handle can be made from a 24 inch length of hardwood (similar to making a stake). Use a knife or ax to round the end of the handle to fit the hole in the mallet head. Secure the handle in place with a wedge placed crosswise to the length of the head.

Guylines – When attaching a guyline, make sure its contact with the stake is as low to the ground as possible. If the guyline is placed or slips higher on the stake, there will probably be enough leverage to pull the stake loose. Guylines should be secured to the structure about 3/4 of the way up. To determine how long a guyline should be, measure the height at the point where its attached and double that distance. That’s how far away the anchor should be from the pole. For example, if the guyline is attached 10 feet up the pole, the anchor should be a minimum of 20 feet from the base.

Page53 Anchors13-2-1 Anchor – As the name implies, the 3-2-1 anchor is made by driving stakes in a series: three stakes, then two stakes, and then one stake to form the anchor. First drive in the set of three stakes. Next drive in the set of two stakes about 24 Page53 Anchors2inches away from the first set. Finally, drive a single stake in the ground about 12 inches from the two-stake set.

Connect the stakes by tying a rope from the top of the three-stake set to the bottom of the two stake set, and from the top of the two stake set to the bottom of the single stake. Use at least two loops of 1/4 inch manila rope, or six to eight loops of binder twine. Then twist the rope tight using a small stick as a tourniquet. After the rope is twisted tight, push the end of the stick in the ground to keep it from unwinding.

Depending on the strain the anchors need to withstand, you can use other configurations, such as 2-1-1, or 1-1-1, or even 1-1 for a light strain.

Log-and-Stake Anchor – This type of anchor is easy to make and can hold a considerable amount of pull. You can tie the line directly to the log, or you can use a ring with a rope grommet as shown in the photo below. To make the log-and-stake anchor, place a log 4 to 6 inches in diameter perpendicular to the pull of the line. Then drive in four large stakes in front of the log. Next, slip the rope grommet through the ring and then slip the ends of the grommet around the log. Drive a second row of stakes 24 inches behind the front stakes. Then anchor the front stakes to the rear stakes with a tourniquet made of binder twine or rope.

Page54 Anchors2

When building anchors, always be sure they are in direct alignment with the strain being applied.

Strops – When attaching lines to a natural anchor such as a tree or large rock, a strop can be used very effectively. Splice a thimble with a large ring to a 10-15-foot length of 1/2-inch diameter manila or polypropylene rope. A piece of canvas or burlap should be used to protect the rope from sharp edges of a rock or to protect the bark of the tree from rope burns.

Ring Shackle

Page45 ShortRope GrommetsRope grommets are useful when attaching a long line to an anchor of stakes. A large grommet can be made by splicing together the ends of a 10-foot length of 1/2-inch polypropylene or manila rope. If you don’t have a spliced grommet in your pioneering kit, tie the ends of the rope with a carrick bend. Be sure to secure the ends. The grommet you use must be made of a larger-diameter rope than the lines they’re connecting, to avoid creating a weak link in the chain between the structure and the anchor.

SinglePullRope grommets can be applied in a variety of configurations. In the above photo, a large ring connects the three ropes from a monkey bridge (left) to a rope that is reeved back and forth between that large ring and the ring of a rope grommet (right), which in turn is attached to the anchor.

Single-Pull, 2-Ring, Monkey Bridge Anchor Configuration

Pioneering Program Curriculum VIII: Building a 3-2-1 Anchor

3-2-1 Anchor
3-2-1 Anchor

This is the eighth post in a series that will eventually comprise an activity-based, unit pioneering program curriculum.

VIII. For a wide range of pioneering structures, proper anchoring is crucial for both stability and safety. When nature doesn’t furnish natural anchors as in trees or boulders in just the right location, it becomes necessary to build your own. Of the two most prevalent approaches to building a very strong anchor, the 3-2-1 Anchor is the most simple. Also, depending on the amount of strain the lines must withstand, this form of anchoring can be constructed in a variety of configurations.

OBJECTIVE
  • By following the proper procedure, Scouts will work together and demonstrate they can correctly build a 3-2-1 Anchor.

MATERIALS

  • six pioneering stakes 30-inch x 2 to 2-1/2 inches
  • two wooden tent stakes
  • two 1/4-inch manila lashing ropes for the tourniquets (an 8 to 10-foot and a 12-1/2 to 15-foot will do)
  • 30 to 50-foot x 3/8-inch manila rope
  • one heavy wooden mallet

PROCEDURE A

With the supervision of the instructor:

  1. Strong Anchor for Pioneering Projects
    Strong Anchor for Pioneering Projects

    Scouts take turns driving three pioneering stakes 18 inches into the ground in a row at a 20° angle using a large wooden mallet.

  2. Scouts take turns driving two pioneering stakes also 18 inches into the ground, at a 20° angle next to each other, spaced 2 feet away from the three-stake set.
  3. In the same way, Scouts take turns driving one more pioneering stake into the ground spaced a foot away from the two-stake set.
  4. As an attentive group, Scouts join the ends of the longer 1/4-inch manila rope with a sheet bend and form a double loop around the three-stake set and two-stake set. Using a tent stake, they twist the loop tight in a tourniquet. The loop is positioned at the top of the three-stake set to the bottom of the two-stake set. Once it is tight they push or tap the tent stake into the ground to keep it from unwinding.
  5. With the shorter 1/4-inch manila rope, Scouts repeat the tourniquet process between the two-stake set and the single stake.

PROCEDURE B

  1. As an attentive group, Scouts tie a butterfly knot about 15 feet from one end of the 30 to 50-foot rope.
  2. Scouts pass the end of the rope that’s 15 feet away from the butterfly knot around the bottom of the three-stake set. (No rope grommet will be necessary for this activity.)
  3. Scouts proceed to form a rope tackle by passing the same end through the fixed loop of the butterfly knot.

PROCEDURE C

  1. One Scout grabs a hold of the hauling end of the rope tackle, and two Scouts grab hold of the other end. On signal, to test the effectiveness of the rope tackle (and indeed the 3-2-1 Anchor!), a short tug of war ensues between the one Scout against the two Scouts.
  2. Scouts take turns at either end of the long rope.

PIONEERING PROJECT: DOUBLE A-FRAME MONKEY BRIDGE!

PIONEERING CURRICULUM: MAIN PAGE

Anchoring Pioneering Projects

The following text is by Adolph E. Peschke as presented in the 1998 printing of the 1993 edition of the Pioneering Merit Badge Pamphlet:

Building pioneering projects often requires some type of strong point for attaching a guyline for a tower or derrick. An anchor point might also be needed to anchor one or both ends of a monkey bridge.

Sometimes nature will provide a tree or rock in just the right location or you might be able to shift the location of the project to take advantage of a natural anchor.

STAKES

Pioneering Stakes

When nature does not provide a solution, anchors can be constructed using stout pioneering stakes.

Note: Under no conditions should tent pegs be used for pioneering stakes. They’re not long enough or strong enough to make a safe anchor.

Pioneering stakes should be made of hardwood, such as oak or hickory. The most common size of stake (for the projects shown in this pamphlet) is 2-1/2 inches in diameter and about 24 to 30 inches long (see figure 84). After cutting the stake to this size, cut a point on one end. Then bevel the top edge to prevent it from mushrooming or splitting when the stake is driven into the ground.

MALLET

Wooden Mallots
Wooden Mallets

When driving stakes into the ground, it’s best to use a wooden mallet. Using a metal sledge hammer or an ax head will damage the stake.

To make a wooden mallet, cut a 4-inch diameter piece of hardwood, such as hickory, elm, or sycamore, about 11 inches long (see figure 85). It should weigh about four pounds. Drill a 1-1/8-inch diameter hole to mount the handle. The handle can be made from a 24-inch length of hardwood (similar to making a stake). Use a knife or ax to round the end of the handle to fit the hole in the mallet head. Secure the handle in place with a wedge placed crosswise to the length of the head.

Buried Spar & Guyline Placement
Buried Spar & Guyline Placement

SOIL CONDITIONS

When driving the stake into the ground, drive it at about a 20° angle. Soil conditions can vary and will dictate how large and long a stake you need. If there will be a heavy strain on the anchor, you might need additional stakes as in the 3-2-1 configuration (shown in figure 89). After the stake is driven into the ground, keep your eye on it as strain is applied to see how it’s holding.

If ground conditions are unsuitable for even the largest stake you have, use a 4-inch diameter spar that’s buried 35 inches in the ground at a 30° angle and anchored in place with a stake (see figure 86).

GUYLINE

Always attach the guyline around the stake as close to the ground as you can get it. If the guyline is placed or slips higher on the stake, there will probably be enough leverage to pull the stake loose (See figure 87).

ANGLES FOR GUYLINES

Both the 3-2-1 anchor and the log-and-stake anchor should be positioned so that the guyline is at a 15° angle, or a maximum of 25°. To determine this, measure the height at the point where the guyline is attached. Double this distance to determine the minimum distance required between the base and the anchor. For example, if the guyline is attached 10′ up the pole, the anchor should be a minimum of 20′ from the base (see figure 88). If your line is long enough, it won’t hurt to place the anchor a few feet further out.

Angles for Guylines
Angles for Guylines and Guyline Length

3-2-1 ANCHOR

Strong Anchor for Pioneering Projects
Strong Anchor for Pioneering Projects

As the name implies, the 3-2-1 anchor is made by driving stakes in a series: three stakes, then two stakes, and then one stake to form the anchor (see figure 89). All six stakes are 30 inches long and are driven 18 inches into the ground at a 20° angle.

First drive in the set of three stakes. Next drive in the set of two stakes about 24 inches away from the first set. Then tie a rope from the top of the three-stake set to the bottom of the two stake set using at least two loops of 1/4-inch manila rope, or six to eight loops of binder twine. Then use a small stick to twist the rope tight in a tourniquet. After the rope is twisted tight, push the end of the stick in the ground to keep it from unwinding.

Finally, drive a single stake in the ground about 12 inches from the two-stake set. Once again, use a twisted rope or binder twine as a tourniquet to hold the two-stake set tightly in place.

Depending on the strain, you can use other configurations, such as 2-1-1, or even 1-1-1 for a light strain. When using any stake anchor, be sure that it is in direct alignment with the strain being applied.

LOG-AND-STAKE ANCHOR

Log-and-Stake Anchor
Log-and-Stake Anchor

The log-and-stake anchor is easy to make and can hold a considerable amount of pull. You can tie the line directly to the log, or you can use a ring-and-rope grommet as shown in figure 90.

To make the log-and-stake anchor, place a log 4 to 6 inches in diameter perpendicular to the pull of the line. Then drive in four large stakes in front of the log. Next, slip the rope grommet through the ring and then slip the ends of the grommet around the log (see figure 90).

Drive a second row of stakes 24 inches behind the front stakes. Then anchor the front stakes to the rear stakes with a tourniquet made of binder twine or rope.

STROPS

It is good practice to use a device called a strop to avoid damage to your long lines. It also makes it easier to tie off your long lines and to make adjustments.

A strop can be made by using a 10-foot length of 1/2-inch diameter manila or polypropylene rope. To make a strop, splice a thimble and ring into one end of the rope (see figure 91), or use a screw pin shackle with a thimble.

The strop can then be wrapped around a rock or tree to attach the line (see figure 92). It can also be used around a spar that is anchored between two trees (see figure 93).

Strops
Strops

Note: Be sure to use a piece of canvas or burlap to protect your rope from sharp edges of a rock or to protect the bark of the tree from rope burns.

GROMMETS

A grommet is often used in conjunction with an anchor. A large grommet can be made by splicing together the ends of a 10-foot length of 1/2-inch manila or polypropylene rope. If you don’t have a spliced grommet in your pioneering kit, tie the ends of the rope with a square knot or a carrick bend. Be sure to secure the ends of the rope.

The completed grommet is useful when attaching a long line to an anchor of stakes. It provides a strong and more convenient way to attach a guyline or other long line.

The grommet you use must be made of a larger-diameter rope than the guyline to avoid creating a weak link in the chain between the structure and the anchor.

Rope Grommet
Rope Grommet

Single Pull Rope Tackle Monkey Bridge Configuration

PDF FILE for: Anchoring Pioneering Projects