Construction Lashings and Structures

Lashings are used to firmly hold together two or more spars (poles, masts, scaffolding, legs, trestles, etc.)  There are numerous survival construction projects that require lashings for construction.

Here is an example of lashings used to hold two posts together (details on how to create lashings below).

Example of lashings holding two posts together

 

Before continuing, it will be helpful to review the various knots and Hitches that lashings require.  The diagram below illustrates some of the lashing terminology used.

Lashing terminology including frapping, turns, and hitch

 

 

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Three basic types of Lashings

There are three basic types of lashings.  The choice of which type of lashing to use are dependent upon the job the spars need to perform.

  1. Square Lashing: used where the spars under load have a tendency to slide over each other at the corners.
  2. Diagonal Lashing: used where the spars may spring away from each other when under a load.
  3. Sheer Lasing: used where spars have to share a load or for joining two spars end-to-end.

 

Square Lashing (used when spars tend to slide over each other)

Step 1: Place the spars in position.

Step 2: Secure one end of the lashing to the vertical spar using a Clove Hitch knot.  Tie the hitch below the horizontal spar.

Square Lashing - secure rope to post

Step 3: Wrap turns under and behind the horizontal spar, over the top part of the vertical spar (above the horizontal spar), and behind the other side of the horizontal spar.  Make three or four turns and work tight each turn made.

Square Lashing - Wrap horizontal turns

Step 4: Wrap three or four more turns but this time wrap them over and above the horizontal spar, behind and over the top of the vertical spar, and over and down the other size of the horizontal spar.  Tighten each turn.

Square Lashing - wrap vertical turns

Step 5: Finish with a Clove Hitch knot on the horizontal spar.

 

Diagonal Lashing (use when spars tend to spring away from each other)

Step 1: Tie a tight Timber Hitch diagonally (vertically) over the crossing.

Diagonal Lashing - begin with Timber Hitch

Step 2: Continue with three or four tight turns in the same vertical direction as the Timber Hitch.  Then wrap three or four tight turns horizontally over the crossing.

Diagonal Lashing - wrap vertical and horizontal turns

Step 3: Finish with a Clove Hitch on one of the spars.

Diagonal Lashing - finish with Clove Hitch

Shear Lashing (use when spars have to share a load)

Step 1: Start with the legs parallel to each other.

Step 2: Tie a Clove Hitch around one of the spars.

Step 3: Wrap about 10 turns around the spars pulling tightly after each turn is made.

Shear Lashing - start with Clove Hitch then wrap 10 horizontal turns

Step 4: Splay out the legs to the required angle.  The tension on the lashings should remain tight.

Step 5: Then wrap 3 or 4 turns vertically where the spars cross.

Step 6: Finish with a Clove Hitch on one of the spars.

Shear Lashing - finish with Clove Hitch

When lashing two poles end to end, complete steps 1, 2, and 3 but do not splay the legs apart and use about 20 turns instead of 10.  Finish with a Clove Hitch around both poles.  You can drive a piece of wood in between the poles to tighten the lashing.

Shear Lashing - how to lash parallel poles

 

 

Other types of lashings

Below are a collection of various types of lashings.

Japanese Square Lashing

Japanese Square Lashing

Japanese Square Lashing

 

 

Figure of 8 Lashing

Figure of 8 Lashing

 

 

Filipino Diagonal Lashing

This lashing required only one knot at the end.  Pull all lashing tight to complete.

Step 1: Start with a bight and put this around both spars as shown.

Filipino Diagonal Lashing - begin with loop

Step 2: Take the two ends back and pull tight.

Filipino Diagonal Lashing - take two ends back

Step 3: Lash with both ropes as shown.

Filipino Diagonal Lashing - lash with ropes

Step 4: Turn and lash in the opposite direction.

Filipino Diagonal Lashing - lash back vertically

Step 5: Divide the ropes between the spars, adding frapping turns as needed.

Filipino Diagonal Lashing - Divide ropes

Step 6: Pull tight and finish with a Reed knot.

Filipino Diagonal Lashing - pull tight and knot

 

 

Gin Tripod Lashing

A quick, strong lashing for lightweight tripods.

Step 1: Make a loop over one of the poles with the ends leading between
the other two.

Gin Tripod Lashing - make loop over pole

Step 2: Lead the long end of the rope above the loop and wrap it around all three poles about five or six times. Put the loop over the wraps and over top of same pole.

Gin Tripod Lashing - lead long end above loop

Step 3: Pull the loop tight with the short end of the rope. Lead the short end over the wraps in the between two poles opposite the loop.

Gin Tripod Lashing - pull loop tight

Step 4: Tie the ends of the rope together with a square knot between the ends of the poles.

Gin Tripod Lashing - tie ends of rope

 

West Country Shear Lashing

This lashing is a series of overhand knots made on alternating sides and finished with a Square Knot. Two lashings make a strong shear joint between two poles.

Steps to construct a West Country Shear Lashing

 

 

Structures

Below are various survival construction projects that use some of the lashings discussed above.

Simple Tower

Simple Tower lashings

Anchors

Here are various ways to anchor construction objects.

Grommet anchor

Log and Stake anchor

3-2-1 anchor

 

Trestle

The trestle demonstrates pioneering construction techniques. Begin by lashing the ledgers to the legs and add the braces. The center diagonal lashing should be tied last. Bracing diagonally give the structure adding great strength and rigidity. This technique is called triangulation. Note that one end of the brace is opposite the other four ends to add locking tension to the brace.

Trestle lashing

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