Rope Safety
Proper selection of the right rope size is the greatest factor in getting full use and long life from your rope. In addition to size, other factors such as the materials used in the construction and covering of ropes, type of lay and special fiber treatment will determine the selection of rope.
In the BDSM world, ropes should always be chosen with extra care to ensure that the rope that you use is suitable for the purpose that you will be using it for. If the wrong rope is used, the rope can abrade or cut skin, decrease or block circulation, or fail under load.
Inspecting rope
New rope should be thoroughly inspected throughout its entire length before it is used to determine that no part of it is damaged or defective.
Rope should be inspected daily if it is used to support people in any way. Inspection should include examination of the entire length of rope for wear, abrasion, broken or cut fibers, displacement of yarns or strands, discoloration or rotting. To inspect the inner fibers, the rope should be untwisted in several places to make sure the inside yarns are bright, clear and unspotted.
If chaffing, excess dirt, cut or worn strands, stiffness, or hardness are found the rope should not be used.
Rope loaded to over 75% of its breaking strength will be permanently injured. Damage from this cause may be detected by examining the inside threads which will be broken to an extent governed by the amount of the overload. Such damage may also be determined by the reduced diameter of the weakened section of the rope.
Slings multiply force on rope
The breaking strength of rope is based on direct pull along a single length of rope. When slings, using two or more legs to carry the load, are properly employed, the rope's safe working load is substantially increased. However, the load factor on each leg of the sling is greatly increased as the sling angle becomes smaller. Therefore, the use of slings requires certain precautions as well as a knowledge of safe working loads permissible. For best results, sling angles should never be more than 90 degrees - rarely less than 45 degrees.
Rope Breaking Strength
Each type and diameter of rope has a different breaking strength. Before you go shopping for rope, you can calculate the approximate minimum size of rope that you will require for a given load. You must always check the applicable breaking strength and safe working load data for the rope that you are going to purchase. Rope breaking strengths are usually clearly marked on pre-packaged ropes; if they are not, always ensure that you are shown the data for the rope before you purchase it.
The basic breaking strength factor for manila rope is found by multiplying the square of the circumference of the line by 900 lbs. Note that rope size is measured by diameter, not circumference.
The basic breaking strength factor for Polypropylene rope is found by multiplying the square of the circumference of the line by 1260 lbs.
The basic breaking strength factor for Nylon rope is found by multiplying the square of the circumference of the line by 2250 lbs.
As an example, if you had a piece of ½" manila line and wanted to find the breaking strength, you would first calculate the circumference. (.5 X 3.14 = 1.57) , so the breaking strength of ½" manila rope is 1.57 x 1.57 X 900 = 2,218 pounds.
The breaking strength of a piece of ½" nylon line would be 1.57 x 1.57 X 900 = 5,546 pounds.
Rope Safe Working Load
Each type and diameter of rope has a different safe working load.
Knowing the maximum safe working load for line can help prevent accidents and tragedies. You should never stress a line anywhere near its breaking strength. As line is spliced, stretched, wears, is subjected to sustained loads, shock loads, loads of many times the recommended working load, subjected to great heat or ultraviolet light for long periods of time it will continually loose some of its strength.
Safe working load is generally thought of as no more than 1/5th of a line’s breaking strength; the breaking strength should be five times he weight of the object the line is going to hold.
When in doubt use a ratio of 15:1. Example: A particular rope's average breaking strength is 1,500 lbs. The recommended working load would be 100 pounds. This rule applies only to rope that is new or in use during normal service life where no shock loads or other damage have occurred.
Cleaning rope
Dragging rope on the ground or over rough, gritty surfaces allows abrasive particles to work into the rope and weaken the fibers.
If rope becomes muddy or dirty, it should be washed and dried thoroughly before storing. Rope may be washed with cold water and moderate hose pressure. Any grit or dirt that remains may be shaken out after the rope has dried.
Storing rope
Rope should always be dry before storing; storing wet rope causes mildew and rot. A cool, dry room with free air circulation makes ideal storage.
If necessary to store on metal or concrete floors, protect the rope with planking to prevent contact with the floor. Get into the habit of coiling your ropes when they are not in use.
Don't leave knots in a stored rope for long periods of time.
Twisted rope should be put into round coils. Right-laid rope, as most twisted rope is, should be wound clockwise, while left-laid rope should be wound counter-clockwise. Preserving the lay of the rope in this way will make for line that coils easily and plays out smoothly.
Braided rope has no preferred direction and often loops into figure eights naturally.
Take three or four feet of line from the back of the coil and make three turns around the coil. Pass a loop of the free end through the top of the coil. Pass the free end through the newly created loop. Take the loop over the top of the coil and pull the free end to fasten. The free end should hang slightly longer than the coil so it can be located quickly.
Another method better suited for storing the line in a rope locker is to double the end of the completed coil to form a long loop. Pass the loop, in a clockwise turn, around the head of the coil, passing the end of the loop under its own midsection. Take another turn around the coil to the left of the first one and tuck the end of the loop under this second turn. Pull tight so that the end of the loop stands free and can be used as a hanger. Again, make sure the free end hangs down a bit so it can be located quickly.