Tag Archives: H-Frame Trestle

Pioneering Curriculum IX: Using a Diagonal Lashing and Making a Trestle

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

Link to: Larger Image
Trestles are often used to support bridge walkways.

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

Basic Four Steps to Tying a Traditional Diagonal Lashing

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.

  1. Cinch the poles together by tying a timber hitch around them where they cross.
  2. Make three wrapping turns on the opposite diagonal to the timber hitch.
  3. Keep the wraps parallel to one another and pull them tight. Make three more tight wraps across the first three, again keeping them parallel.
  4. 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:

Trestle Formed with Scout Staves
Trestle Formed with Scout Staves

 

  1. Lay out two poles parallel to one another as the trestle legs.
  2. 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.
  3. Turn the legs and ledgers over and place one pole diagonally over two of the legs as one of the X-braces.
  4. Where it intersects, join this pole to the legs with two tight square lashings.
  5. Place the last pole diagonally OVER one leg and UNDER the other leg, as the other X-brace.
  6. Where it intersects, join this pole to the legs with two tight square lashings.
  7. Stand the structure up. There should be a gap between the the two X-braces where they cross in the middle.
  8. Using the 10-foot lashing rope, spring the X-braces together with a tight diagonal lashing.
  9. 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

PIONEERING CURRICULUM: MAIN PAGE

Troop Meeting Challenge: Roman Chariot Race

A Chariot ace during an Introduction to Outdoor Leader Skills Training Session
A Chariot Race during an Introduction to Outdoor Leader Skills (OLS) Training Session

As stated by John Sweet in Scout Pioneering, “The chariot race originated at Gilwell in the early days of Leader Training and for many years was used on every Scout Wood Badge Course as a classic demonstration of B.P.’s method in action:

  • the Patrol as the unit of activity
  • the immediate application of newly acquired skills (Square Lashing, Diagonal Lashing)
  • the construction of a basic unit in mainline pioneering (the trestle)
  • light-hearted competition between Patrols”

The classic chariot race has been run in a variety of ways. This one uses an H-Frame Trestle, which is the basic component of many pioneering projects. For that matter, in pioneering circles when we refer to a trestle, we mean the H-Frame, so there should be no confusion. As stated, there are a variety of ways to run a chariot race. One thing to note: depending on how the chariot is transported, it can be hard on turf, so think twice before dragging it on a nice lawn! That’s the very reason why one way to run it is to have the rider hold on as the trestle is literally picked up and carried by at least four patrol members. Many times, when the chariot is dragged, the “charioteer” simply stands on the ledger and holds onto the transom, as patrol members grab onto any part of the trestle they can reach. But, to imitate an actual chariot to the fullest extent, the rider should grab a hold of a rope serving as the “reins” while two other Scouts act as “wheels” keeping the chariot upright, as patrol members pull the chariot like horses using two hauling lines tied to the transom at each leg.

In mainline Pioneering the classic proportions of the trestle are as shown in the diagram, but for the chariot race, the trestle should be tailored to suit the charioteer.

From: Scout Pioneering – Patrols in Action, by John Sweet

This interpatrol activity can be presented indoors or outdoors. If indoors, and the trestle is dragged, care should be taken to avoid scuffing the floor of the church fellowship hall or damaging the carpet. The following is furnished for each patrol:

Materials (Heavier Version)

  • two 8-foot x 2 to 3-inch diameter spars for the legs
  • four 6-foot x 2 to 3-inch diameter spars for the ledger, transom, and cross braces (The ledgers can be 4 to 6 feet in length.
  • nine 15-foot lashing ropes
  • one 10-foot lashing rope for the reins
  • two 15-foot lashing ropes for the hauling lines

Materials (Light Version)

  • six Scout Staves
  • nine lashing ropes (6 feet will do for the 8 square lashings and a 10-footer for the diagonal lashing)
  • one 10-foot lashing rope for the reins
  • two 15-foot lashing ropes for the hauling lines
See Note 1 and 2. Adjust the angles between the ledger and the legs so they are less than 90º and make sure the width between the legs at the ledger is narrow enough so the charioteer can plant his feet right next to the legs.
See Note 1 and 2. Adjust the angles between the ledger and the legs so they are less than 90º and make sure the width between the legs at the ledger is narrow enough so the charioteer can plant his feet right next to the legs.

Note 1: When using Scout Staves (Light Version), it will be necessary to angle the legs inward from the ledger to the transom. When the angle between the legs and the ledger is less than 90º, the lashings are much less likely to slip down over the smooth surface of the Scout Stave. That will mean, the distance between the legs where the transom is to be lashed will need to be less than the distance between the legs where the ledger is to be lashed.

Note 2: Since the Scout Stave comprising the ledger will bow and possibly break if the feet of the charioteer are not planted as near as possible to the legs, it is necessary to lash the ledger to the legs at a width that will  correspond comfortably with the size of the charioteer.

On signal, each patrol will build a trestle as per the above drawing. As soon as their “chariot” is built and they have selected a “charioteer” (usually their lightest member), two members to hold the trestle upright, and their “horses,” they run a specified course or race to a turn-around-line and back to where they started.

Note: A Mark II Square Lashing can be used to spring the spars together at the X-brace, in lieu of a diagonal lashing.