Pioneering Program Curriculum V: Shear Lashing

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

SUPPORTING VIDEO: How to Tie a Shear Lashing

V. With the square lashing under their belts, Scouts can start to actually build pioneering projects. Though the basic and oft-used A-frame can be readily completed using three square lashings, the shear lashing is most frequently chosen to start lashing together this common support structure.

OBJECTIVES

A. Scouts will demonstrate they can tie a shear lashing by:

  1. starting off the lashing with a clove hitch around one pole
  2. wrapping the lashing rope eight to ten times around both poles
  3. taking two frapping turns between the poles around the wraps
  4. completing the lashing by applying two half hitches around the opposite pole (clove hitch)

B. Scouts will demonstrate they can construct an A-frame by:

  1. connecting the tips of two poles with a shear lashing
  2. spreading the poles apart to form an inverted ‘V’
  3. lashing a pole to the butt ends of the ‘V’ with square lashings

MATERIALS

  • Three Scout Staves for each Scout
  • One 10-foot x 1/4-inch manila lashing rope for each Scout
  • Two 6-foot x 1/4-inch manila lashing ropes for each Scout

PROCEDURE A

1) The instructor shares the purpose and application of the shear lashing, explaining how we use it when we want to connect two spars and open them out to form the legs of an A-frame.

2) Scouts gather around the instructor who, using two Scout Staves and a 10-foot lashing rope, demonstrates lashing the ends of the staves together with a shear lashing, narrating each step as he does.

Two Scout Staves joined at the end with a Two-Stave Shear Lashing
Two Spread Scout Staves Joined at the Top with a Two-Spar Shear Lashing

3) With the assistance of the instructor(s), using two Scout Staves and a 10-foot lashing rope, each Scout proceeds to to tie a shear lashing applying the following steps:

  • The two staves are placed parallel to one another either on the ground, resting on a log, or leaning against a wall.
  • A clove hitch is tied to one of the staves at around 6 inches from the end. (Depending on the structure being lashed together, the placement of the clove hitch can vary from 6 inches to 18 inches or more, from the end of the spar.)
  • A 4 to 6-inch tail is left in the short running end, which is wrapped around the standing part serving to secure the clove hitch, before proceeding with the wraps.
  • The long running end is wrapped around both staves eight times, evenly and away from the ends. (The directive is 8 to 10 wraps, and sometimes as little as 5. The greater number of wrapping turns, the stiffer the lash will be.)
  • After the wraps, both staves can be held upright and spread a bit to make room for two tight frapping turns taken around the wraps and between the staves.
  • After the fraps, a half hitch is applied to one stave. cinched up close to the fraps and pulled tight. Then another half hitch is applied, cinched up and tightened to form the finishing clove hitch. (Preferably, but not necessarily, the final clove hitch is tied to the opposite pole on the opposite side of the first clove hitch.)
  • The two legs are spread farther apart to form and inverted ‘V’ and the lashing is evaluated to determine if it is well-formed and tight enough to resist sliding.

PROCEDURE B

1) When their shear lashing is adequately completed, each Scout is given a third Scout Stave and two 6-foot lashing ropes.

2) With square lashings, each Scout joins one end of the third stave to one leg of the inverted ‘V’ and then the other end of the third stave to the other leg of the inverted ‘V.’ (Both ends should be lashed in the same position on each leg, and the square lashings should be tied tightly so they don’t slip.)

3) When all three lashings are well-formed and tight enough, each Scout should pick up the resulting A-frame and give it a shake, testing that it is indeed sturdy.

Page 397
Shear Lashing with Plain Turns

INTERPATROL COMPETITIONSimple A-Frame Chariot Race

Related Post with Photographed Lashing Procedure: The Somewhat Ambiguous Shear Lashing

PIONEERING CURRICULUM: MAIN PAGE

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