G Evaluation

a MLC - You will be tested later in the course by written and performance evaluations on this period of instruction.

g ACC - You will be tested later in the course by written and performance evaluations on this period of instruction.

Q SMO - You will be evaluated by an oral and performance evaluation later on.

TRANSITION: Are there any questions on the learning objectives, how I will be presenting this period of instruction, or how and when you will be evaluated. Let's now discuss the two types of anchors.

BODY

1. (5 Min) TYPES OF ANCHORS. There are two types of anchors that we use. These two types are:

g| Natural b Artificial

TRANSITION: We will now take a look at considerations for anchors.

2 (5 Min) GENERAL CONSIDERATIONS FOR ANCHORS. Anytime you employ natural or artificial anchors; there are special considerations that you must apply. These considerations apply both to the anchor itself and to the material being used to build the anchor. Some examples of these considerations are:

Whether using natural or artificial anchors, the installing unit must insure that the anchor is suitable for the load.

b The anchor position must be relative to the direction of pull on the anchor.

9 The angle between the anchor points should not exceed 90 degrees. This is to ensure that no added stress is put upon the anchors, as well as the equipment being used to construct the anchor.

^^To decrease the angle between anchor points, materials (i.e. sling ropes, web runners, prusik cord, etc.) could be used to extend the anchor which will decrease the angle between anchor points.

TRANSITION: We have just talk about considerations for anchors. Are there any questions? Now we will talk about Natural Anchors.

(15 Min) NATURAL ANCHORS. A natural feature is the preferred type of anchor point.

Some examples and considerations are as followed:

a. Types of natural anchors.

MB Select a tree that has not been chopped, burned or is rotten.

b^E The tree should be at least 6" in diameter and strong enough to support the intended load.

MS Trees growing on rocky terrain should be treated with suspicion, since the roots normally are shallow and spread out along a relatively flat surface.

RUNNER USED AROUND A TREE

IShrubs and Bushes.

RUNNER USED AROUND A TREE

Select a shrub or bush that is alive and is not brittle, charred or loose.

To avoid leverage, locate the central root and construct the anchor as near to the base as possible.

Boulders Rocks

H 0 Good Bad

PROPER AND IMPROPER PLACEMENT ON NATURAL ANCHORS Rocks and Boulders.

H 0 Good Bad

PROPER AND IMPROPER PLACEMENT ON NATURAL ANCHORS Rocks and Boulders.

Stability is of prime importance when considering a rock or boulder for an anchor. It must be strong enough and secure enough for the intended load.

All surfaces of the rock or boulder should be inspected for any rough or sharp points. These areas must be padded to protect the rope from being abraded or cut.

PROPER AND IMPROPER PLACEMENT OF A RUNNER OVER A BOULDER

¡Spikes and Flakes.

MBTq check stability of a spike or flake, thump it with the heel of your hand. Anything that sounds hallow is suspicious.

b )They should be checked for cracks or other signs of weathering that may impair their firmness.

¡Sharp edges must be padded to protect the rope against cuts and abrasion.

RUNNER OVER A FLAKE

¡Threads and Chockstones.

0A thread is when the rock weathers or cracks to form a hole in the main wall. A chockstone is a rock wedged in a crack.

b_)Check a thread by thumping it with the heel of your hand. Make a visual inspection for cracks and weather. Common sense will prevail for choosing this type of anchor.

)When choosing a chockstone, ensure that it has substantial contact with the crack and that the stone's symmetry corresponds with the intended direction of pull.

Chockstone
RUNNER IN A GIRTH HITCH OVER A CHOCKSTONE

9 Types of Natural High Tension Anchors. The following are types of Natural High Tension Anchor Systems used to construct installations. These can be tied on any suitable natural anchor point:

^®Tree Wrap Anchor. The tree wrap is an anchor used to relieve tension on the actual knot itself. This system requires more rope when tied around a large anchor point.

MB Tie a Figure 8 Loop on the standing end of the rope and wrap the 4-6 times around an anchor point.

Attach a locking carabiner through the knot's loop and clip it onto the running end of the rope.

Rope Anchor Carabiner Knot

NOTE: If the anchor point to be wrapped is larger then 18' around, then three wraps will suffice.

^Swammi Wrap Anchor. When tying the Swammi Wrap, ensure that the joining knot is kept on the side of the anchor point. The Swammi Wrap can be loosened under load if need be. This system can be substituted for a tree wrap when the installation's rope length is an issue.

«^Select a suitable anchor point and tie a Swammi Wrap around it.

b^BClip a locking carabiner into as many wraps as possible. This will serve as the attachment point for the anchor system.

igure of 8 Anchor. The Figure of 8 Anchor is a quick and efficient system. This system cannot be loosened under load. It is tied in the following manner:

M) Tie a Figure of 8 Loop on the standing end of the rope and wrap the knot around a suitable anchor point. Attach a locking carabiner through the knot's loop and clip it onto the running end of the rope.

(b) Before tensioning the anchor system, adjust the tree wrap so that the running end of the rope runs smoothly through the carabiner towards the direction of pull. This will prevent any lateral tension.

Hf two ropes are used, the upper rope's carabiner has its gate upwards, and the lower rope's carabiner has it's gate downward.

c. Primary and Secondary Natural Anchor Point System. The two anchor points should be in line with the direction of pull. The primary anchor is the point nearest the running end while the secondary anchor point is directly behind the primary. It is constructed in the following manner:

The primary anchor knot should be an around the object clove hitch. This is chosen for ease of untying the system after tension has been placed on the rope.

9E The secondary knot is tied around a suitable anchor point ensuring that the rope is taunt between the two anchor points.

9E Only one anchor point is required when:

MfllJsing a tree with a diameter of 12" or more, and it can handle the intended load safely.

IWhen constructing a retrievable system.

NOTE: If constructing an anchor system in which only one natural anchor of less then 12" diameter exists, it must be backed up by two pieces of artificial protection.

TRANSITION: Now that we have discussed natural anchors, are there any questions? Let's move on to artificial anchors.

4| (10 Min) ARTIFICIAL ANCHOR SYSTEMS. Any time we use anything other then a natural feature, we are using an artificial anchor point. Artificial anchors can be constructed in the ground, or on the rock itself. The following are artificial anchor systems:

3! Single Timber Deadman. This system is constructed in the ground and it requires considerable time and effort. The steps of it's construction are as follows:

Dig a trench 6 feet long and 3 feet deep and wide enough to work in at a 90 degree angle to the direction of the pull.

Timber Deadmen
SINGLE TIMBER DEADMAN

Dig another trench about 12 inches wide. This trench is dug so that it intersects the main trench at a right angle in the middle. The bottom of this trench should be parallel to the direction of pull and should join the bottom of the main trench.

^E Take an anchoring device (i.e. log, engineer stakes, bundled up branches etc.) that is strong enough to support the intended load. The anchor is placed into the main trench and covered with dirt with the exception of that part of the anchor that joins the second trench. Stakes approximately 3 feet long should be driven approximately 1-1/2 feet into the ground between the dead-man and the slanted side of the trench to assist in holding the dead-man in place if the soil is soft.

¡9 Picket Hold Fast. The picket hold fast is an easier anchor to construct than the deadman, and can be used almost anywhere. The strength of the picket system depends on the pickets and the soil or snow conditions. The picket system can be used for both high and non-tension systems. Construction is as follows:

PICKET HOLD FAST

PICKET HOLD FAST

with a sling rope, tie a round turn and two half hitches at the base of that picket. With the running end of that sling rope tie a round turn and two half hitches at the top of the middle picket. Using a second sling rope tie a round turn and two half hitches to the base of the middle picket. Then with the running end of that sling rope tie a round turn and two half hitches to the top of the picket closest to the cliff edge.

Q Equalized Anchor. This system is built with a minimum of three pieces of protection. It can be tied with the standing end of a rope or by utilizing a practice coil.

Construction with the Standing End of the Rope:

¡¡Tie a Figure of 8 Loop in the standing end of the rope.

¡Place a carabiner in each artificial anchor point and attach the knot in either of the outside carabiners.

¡Clip the rope into the remaining carabiners.

)A bight of rope is then pulled down after each carabiner into the anticipated direction of pull. With all three bights, tie an overhand knot around itself to include the running end of the rope.

¡With the running end of the rope coming from the overhand knot, tie a Figure of 8 Loop and attach it to the overhand knot's loop with a locking carabiner.

Ensure that there is sufficient slack in the dead rope to prevent a possible shock loading of the system.

^Construction with the Cordalette Method:

¡Create an endless loop with a practice coil and clip it into each of the artificial anchor points.

A bight of rope is then pulled down between each carabiner into the intended direction of pull.

With all three bights, tie an overhand knot on itself.

^JPlace a locking carabiner into the overhand knot's loop. This will serve as the attachment point for the anchor system.

NOTE: If constructing a two-rope high-tension installation, a minimum of three artificial anchors per rope will be used.

TRANSITION: During this period of instruction we have discussed natural and artificial anchors, are there any questions? If you have none for me then I have some for you.

Was this article helpful?

+1 0

Responses

  • barbara
    What to use for 90 degree pull on anchor?
    8 years ago

Post a comment