Tarring (rope)
Encyclopedia
Some types of rope
Rope
A rope is a length of fibres, twisted or braided together to improve strength for pulling and connecting. It has tensile strength but is too flexible to provide compressive strength...

 must be protected from rot by tarring, coating the rope with tar
Tar
Tar is modified pitch produced primarily from the wood and roots of pine by destructive distillation under pyrolysis. Production and trade in tar was a major contributor in the economies of Northern Europe and Colonial America. Its main use was in preserving wooden vessels against rot. The largest...

. Hemp
Hemp
Hemp is mostly used as a name for low tetrahydrocannabinol strains of the plant Cannabis sativa, of fiber and/or oilseed varieties. In modern times, hemp has been used for industrial purposes including paper, textiles, biodegradable plastics, construction, health food and fuel with modest...

 rope requires tarring, but Manila
Manila hemp
Manila hemp, also known as manilla, is a type of fiber obtained from the leaves of the abacá , a relative of the banana. It is mostly used for pulping for a range of uses, including speciality papers. It was once used mainly to make manila rope, but this is now of minor importance...

, cotton, and synthetics do not. Regular tarring at sea was required when sailing ships used hemp rope.

Tarring down


Tarred rigging manufacture in 1913

"The use of tarred
Pine tar
Pine tar is a sticky material produced by the high temperature carbonization of pine wood in anoxic conditions . The wood is rapidly decomposed by applying heat and pressure in a closed container; the primary resulting products are charcoal and pine tar.Pine tar consists primarily of aromatic...

 rigging
Rigging
Rigging is the apparatus through which the force of the wind is used to propel sailboats and sailing ships forward. This includes masts, yards, sails, and cordage.-Terms and classifications:...

 is now of less interest to the seafaring man than formerly because of the rapid and extensive development of steam power. However, tarred rigging is used to-day on craft of various types to such an extent that the production of tarred goods is an important branch of the cordage industry. The tar best suited for cordage comes from various members of the pine tree family, and is obtained by the distillation
Distillation
Distillation is a method of separating mixtures based on differences in volatilities of components in a boiling liquid mixture. Distillation is a unit operation, or a physical separation process, and not a chemical reaction....

 process, either by using the old kiln
Kiln
A kiln is a thermally insulated chamber, or oven, in which a controlled temperature regime is produced. Uses include the hardening, burning or drying of materials...

 or by modern retorts
Retort
In a chemistry laboratory, a retort is a glassware device used for distillation or dry distillation of substances. It consists of a spherical vessel with a long downward-pointing neck. The liquid to be distilled is placed in the vessel and heated...

. It is conceded that the kiln-made article is superior for tarred rigging, and therefore it is used principally in making first quality tarred rope. The tar, as it comes from the kiln, is poured into barrels which are shipped to the cordage works. The way this tar is handled and how it is made to penetrate and adhere to the yarn, as is done by the Plymouth Cordage Company
Plymouth Cordage Company
The Plymouth Cordage Company was a rope making company located in Plymouth, Massachusetts. The company, founded in 1824, had a large factory located on the Plymouth waterfront. By the late 19th century, the Plymouth Cordage Company had become the largest manufacturer of rope and twine in the world...

, North Plymouth, Mass., may be described as follows:

"The tar is heated to 200 degrees or more in tanks from which the liquid feeds into long copper-lined troughs, where the tarring takes place. Through these "coppers," so called, run steam pipes to further regulate the temperature. Excessive heating would cause the loss of the tar's good qualities, and to prevent this the supply in the "coppers" must be freshened frequently. As the yarns, heavily saturated with tar, come from the "copper" they are compressed between two rollers, adjusted to leave in the yarn as much or as little tar as needed for the particular goods being made and to turn back the surplus. The pull which carries the yarn through the tar and between the rollers comes from two large drums, around which the yarns travel preparatory to reeling on to the friction-driven receiving bobbin
Bobbin
A bobbin is a spindle or cylinder, with or without flanges, on which wire, yarn, thread or film is wound. Bobbins are typically found in sewing machines, cameras, and within electronic equipment....

s. Goods of nine-thread size and under are usually tarred in the completed rope form, but the process is essentially the same as with the yarns. The rich golden brown color of the tarred goods—an outward sign of right materials and methods—has become recognized as the Plymouth mark of the weather-resisting qualities contained in the goods."
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