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

**SUPPORTING VIDEO: How to Tie a Diagonal Lashing**

IX A. The diagonal lashing gets its name because the wraps form a diagonal where they cross the spars. It’s primary use is to spring together two spars that are not touching when the ends are lashed in place on a structure (as in a trestle).

IX B. The trestle is a basic component of many pioneering projects. When we speak of a trestle, we’re referring to what has been dubbed an H-trestle. The way it’s designed yields a very strong supporting structure that is often used as a subassembly for something larger, and frequently serves to support the walkways of a bridge.

OBJECTIVES

- Each Scout will tie a diagonal lashing to effectively spring together the X-brace of a trestle.
- Working individually or in small groups, Scouts will properly construct a trestle.

MATERIALS

- two 6-foot x 2 to 3-inch spars and 15-foot lashing rope for demonstration
- six Scout Staves for every four Scouts (six will be needed for each trestle)
- two 6-foot x 1/4-inch manila lashing ropes for every Scout (eight will be needed for the square lashings on each trestle)
- one 10-foot x 1/4-inch manila lashing rope for every Scout (one will be needed for the diagonal lashing on each trestle)

PROCEDURE A

Using the 6-foot spars and the 15-foot lashing rope, Instructor demonstrates a diagonal lashing, then using a 10-foot lashing rope and two Scout Staves, with the aid of an instructor and following the basic four steps, Scouts will tie a diagonal lashing.

- Cinch the poles together by tying a timber hitch around them where they cross.
- Make three wrapping turns on the opposite diagonal to the timber hitch.
- Keep the wraps parallel to one another and pull them tight. Make three more tight wraps across the first three, again keeping them parallel.
- Take two frapping turns between the poles, tightly around both sets of wraps and complete the lashing with a clove hitch around one of the poles.

PROCEDURE B

With eight 6-foot lashing ropes, one 10-foot lashing rope, and working individually or in a group of up to four individuals, Scouts will follow the following procedure and build a trestle:

- Lay out two poles parallel to one another as the trestle legs.
- Place a pole over the legs at the top and bottom to serve as the ledgers, and then lash them to the legs with four tight Square Lashings using the 6-foot lashing ropes.
- Turn the legs and ledgers over and place one pole diagonally over two of the legs as one of the X-braces.
- Where it intersects, join this pole to the legs with two tight square lashings.
- Place the last pole diagonally OVER one leg and UNDER the other leg, as the other X-brace.
- Where it intersects, join this pole to the legs with two tight square lashings.
- Stand the structure up. There should be a gap between the the two X-braces where they cross in the middle.
- Using the 10-foot lashing rope, spring the X-braces together with a tight diagonal lashing.
- The completed trestle should be sturdy enough to be lifted and shaken without losing its shape or becoming loose. After building their trestles, Scouts are ready to have a Roman Chariot Race.

**INTERPATROL COMPETITON: Roman Chariot Race**

**PIONEERING PROJECT: ****Single Trestle Bridge**

**PIONEERING PROJECT: ****Single Lock Bridge**