Tuesday, November 22, 2011

Knot Dilemmas

There are hazards to avoid with some knots.

The Slip Knot Dilemma:
A common practice is to use a slip knot to back-up a new climber.  There are two outcomes to tying a slip knot.  One can capture the climber's leg and make rescue problematic.  The other slip knot can't form a cinch.

In this illustration, the top slip knot is a problem.  The bottom one is OK.  Tie them and place them on your foot and pull.  The top knot will cinch while the bottom knot doesn't.

The Fatal Buntline:
If a carabiner is clipped into each of the buntlines, the one on the right will slide off the end of the rope and fail.  By definition, the one on the right is a buntline, yet its use has a potentially fatal outcome.

There's a similar problem with the scaffold hitch.

How to Electronically Draw a Knot

This provides a set of instructions to made simple knot graphics.

Take a photo using white colors.  Upload to Picasa.
Picas has tools to lighten the photo.

Convert it to a black and whte image.

Move the image to Microsoft Paint and trace the rope with a curving black line.

It's helpful to zoom the image to 200% and listen to TED.com or NPR.org in the background.

Save the image and return to Picasa.  Once the image is viewed in Picasa again, use the edit tool to completely whiten the original photographed image.

Return to Paint if a final color finish is desired.

Sunday, November 20, 2011

Use the Blakes Hitch Instead of the Taut-line

The taut-line is a friction hitch knot traditionally taught in scouts.  A common use is to tie tent guy lines for the purpose of adding tension.  The benefit is that the tent is held tight and secure.  Unfortunately, this knot easily loosens and fails.  I've climbed on this knot; I know.  I've spoken to scouts who took turns through a stormy night re-securing their taut-line hitches.

The Blakes hitch provides the same functionality, yet it incredibly more stable than the taut-line.  The coil construction of the Blakes provides this improvement.  For the simple fact that the Blakes hitch has more coil, that's enough merit  to prefer it.  Coils add friction and friction yields stability.

Even consider the the Prusik to replace the taut-line.  It's the gold standard on holding a position.

Here's the taut-line.  Keeping with our tent application, the loop goes around the ground steak.  The upper line connects to the tent.  Tension is created by advancing the knot up.
Here's the more stable Blakes hitch tied in a manner used to add tension to a guy wire.
This depicts a system where the connection is established with a buntline knot (top of image).  The buntline captures the object to be pulled (like a grommet of tarp or tent).  The loop formed beneath the Blakes hitch would capture an anchor (like a tent stake).
Here's the rock solid Prusik loop. It could readily replace the Blakes hitch.  To form the Prusik loop a double fisherman's knot was tied.  The Prusik attaches to the line, which acts as the guy-wire.  There's a feature here.  The guy-wire beneath the Prusik remains loose.  This loose strand could have a back-up knot added (e.g. slip knot).

In case a climber familiar with the traditional arborist climbing system comes along, there's some explaining warranted on the Blakes hitch.  Below is the ubiquitous Blakes hitch application for climbing a tree on double rope.  The guy line application above requires that the Blakes hitch be tied upside down.  This is a great meditative moment for the arborist to compare the two.

Thursday, November 17, 2011

The One Handed Clove Hitch

The one handed clove hitch demonstrates how the hand can be used reliably like a knot tying machine.  The strategy is to put your natural hand movements into sequence.  From this, two beneficial dynamics emerge: 1) bight on bight tying builds knots faster than reeving the end of the rope 2) consistent hand movements embed knot memory (like a piano player).  Moreover, this builds your preparedness skills.

Here's the video version as a reference:

The opening move is to capture a bight of rope on your small finger.  This simple step leaves the majority of your hand available for more work.
Holding your small finger fixed in space, rotate your hand in the direction that your palm faces.  Think of this move as the thumb sweeping out an arc as it points down.  Once the thumb reaches the down position, your middle three fingers grasp the rope.
Now rotate the thumb back up, while maintaining that three finger grasp.  A loop will form.  Note how your small finger positions underneath the point of intersection.  Open your middle three fingers.  You have just captured the first loop of the clove hitch.  Moreover, this loop represents the start of numerous other knots.
Curl your hand to scoop of the left strand of rope.
When your thumb returns to the up position, you're now holding a bight on the outer part of your fingers.  In total, a loop plus a bight is being held.  This forms the Munter hitch.  To complete the clove hitch, that bight needs to be turned into a loop.  The target is to move the left strand inside the palm of the hand.
Insert your thumb to lift the bight off of your fingers.
Now the work of rotating the bight begins.  Squeeze your middle fingers deep inside the palm of your hand.  This serves to force a twist into the bight - resting on your thumb.
As the squeeze is completed, the rope slips off the thumb.  The thumb nudges the rope back onto the fingers.  This action transfers a loop on your fingers.  You're now holding two identically shaped loops on your hand.  These two loops are the components that make the clove hitch.

By straightening your middle three fingers, the clove hitch is dressed into position.  It's ready to use.

Monday, November 14, 2011

How to Tie the Scaffold Hitch with One Hand

What I like about the video on tying the scaffold hitch one handed is that it clearly demonstrates how the bight, loop and elbow come into play to build a knot.

Video link:

Sunday, November 13, 2011

The Quick Tie Spanish Bowline

The triangle of advanced knot skill applies here: 1) bight-on-bight tying 2) initial hold position is critical 3) use the hand as a template.  The quick tie method for the Spanish bowline utilizes mostly #1 and #2 here.  The hand template is used in the opening move.  This serves to introduce the Van Gorder's pretzel, which is a loop folded on a bight.  Van Gorder has developed more than 26 knots from this pretzel starting point.  It's a game changer for tying the Spanish bowline.

Here's the video version:

After pulling B and C out, turn B counter clockwise, and turn C clockwise.

The Spanish bowline has been mentioned as the basis of an emergency harness made from rope. The two characteristic loops hold the legs.  I've used it as a foot loop for SRT RADS.

Here's the video version:

Wednesday, November 9, 2011

Making The Fisherman's Knot with the Contour of Your Hand

A finished double fisherman's knot or grapevine knot will symmetrically fit together.  It would resemble this illustration where the two knots lock into each other. Here's the video link:

If one of your rope ends is started in the wrong direction, then the two knots never perfectly fit together.  It would look like this below.

The following steps will assist you in tying your double fisherman's knot correctly.  The key is to use the contour of your hand to direct the knot.  Start by pointing your thumb to the rope that will make the fisherman's knot.

The other end is held with the hand and will be tied in a later step.  Next take the other end and wrap it around the thumb twice.

When the thumb pulls out, there will be a clear channel through the two loops.  Insert the end of the rope to make an interim knot.  This happens to be the anchor hitch, and it makes a good transition.

Roll the anchor hitch into a fisherman's knot by setting the loop closest to the end over the other.

Now dress it tightly to form the first fisherman's knot.

Rotate the knot over, moving the fisherman's knot from the left to the right.  

Using the same hand as before, tie the second fisherman's knot.

When you finish, you'll have a double fisherman's knot that nicely fits together.

A common application is to form a loop with the double Fisherman's knot.  Loops are typically added to climbing or rigging ropes with a Prusik friction hitch.  This creates an attachment point to a rope or provides a hold - in the case of a climbing scenario.

Here's an example of a loop.
Rotated around, the opposite side is shown below.

Here's the video link:

Monday, November 7, 2011

More Details on The Blakes Hitch

This illustrates how to tie it in more detail.  Moreover, it points out a grave error if tied incorrectly.  The incorrect way fails to hold.