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CHAPTER II.

ROPE KNOTTING AND SPLICING.

§ I. ROPE.

The rope commonly used on ship-board is of three kinds: Hemp, tarred and untarred, Manila and Wire. Coir is sometimes used for heavy tow-ropes, for which it is particularly well adapted by buoyancy, but not by strength. Ropes are made also of flax and cotton, but these are not suitable for use at sea.

Full particulars as to ropes of all types used in the United States Navy are given in tables in the Appendix, which tables should be consulted in connection with this Chapter.

Much confusion results from the common practice of designating all ropes made from vegetable fibre, as "hemp." This mistake is almost universally made by other than sea-faring people in referring to manila; which is sometimes called "manila hemp," but oftener simply "hemp."

Hemp rope is made from the fibre of the hemp plant, which is cultivated extensively in many parts of the world, but especially in Italy, Russia and the United States. Russian and American hemp are very generally used for cordage in the United States.

Manila rope is made from the fibre of the stalk of the wild banana and comes principally from the Philippine Archipelago. As has been noted above, it is commonly designated as "Manila hemp."

Coir is made from the fibre of cocoanut husks. As it is very buoyant and does not become water-logged, it has a great advantage over hemp, manila, and wire, for some purposes, but unfortunately it has only about one-fourth the strength of ma

nila.

In the manufacture of rope from the original fibres, these are twisted together into threads or yarns, which in turn are twisted into strands. A number of strands are laid up into a rope, and sometimes several ropes are combined to form a cable. (Plate 14.)

Wire Rope Clips. (Showing Method of Applying.)

WIRE ROPE.

Note.-Type 6, U. S. Navy, used for hawsers, is identical with Type B, except that it has 14 wires in each strand.

Fig. 3. Tests of Clips on 1-inch Wire Rope. (Rope broke at 54.000 lbs)

The twisting which is necessary in these various processes weakens the rope very materially; at least one-third of the original strength of the fibres being lost. On the other hand, the twisting adds considerably to the elasticity of the rope.

To counteract the tendency to unlay, the successive twists are taken in opposite directions; yarns being usually right-handed, strands left-handed, ropes right-handed, and cables left-handed. The above rule may be reversed, producing "left-handed" or "back-handed" rope.

Rope is commonly made with three strands, but four are sometimes used. In this case, the strands are laid up around a "heart" which fills the space that would otherwise be left within the rope. The rope thus produced is called four-stranded or "shroud-laid" rope.

The

Hemp rope as at present used is almost invariably tarred. In this form it is used for such of the standing rigging as is not of wire, and for the heaviest of the running rigging;-such as lifts, tacks and sheets of courses, topsail sheets, etc. tar preserves the rope from deterioration due to the dampness, but reduces its strength and flexibility. Hemp when not tarred is know as "white-rope" and is the strongest rope used except wire.

Manila is used for most of the running gear, for reeving off purchases, and for the greater part of the miscellaneous work of the ship. It is somewhat weaker than untarred hemp, but does not deteriorate so rapidly from moisture.

Both the manila and the hemp rope of commerce vary greatly in quality. At their best, both should show a smooth, even surface when laid up, with few projecting ends of the fibres. When unlaid, the strands should show long and glossy, without admixture of short ends or "tow."

The strength of a rope-yarn varies from 75 to 100 lbs.

For special purposes, rope is sometimes plaited instead of laid. This does away with the tendency to kink.

Rope is designated as to size by its circumference, and runs from about three quarters of an inch to sixteen inches and even more; but the largest sizes are never seen on ship-board, twelve inches in manila and seven inches in wire being about the maximum that even the largest ship would carry. Its length is measured in fathoms.

Small cordage is usually known on ship-board as "smallstuff," and designated either by the number of threads that it contains, as "18-thread stuff," "15-thread stuff," etc.;or as "Ratline stuff," "Seizing stuff," "Marline," "Spunyarn," etc. These are usually of American hemp, tarred, and are measured in some cases by the fathom, in other cases by the pound.

The following are the most common varieties of small-stuff used on shipboard.

Spun-yarn. A rough and comparatively cheap stuff made from long tow and loosely laid up, left-handed, of two, three or four strands. It is more used on shipboard than any other variety of small-stuff, being convenient for seizings, service, etc., where great neatness is not required.

Houseline, Roundline and Marline are used for the same purposes as spun-yarn, but make neater work, being laid up more smoothly and of better material.

Marline is 2-stranded left-handed, houseline 3-stranded lefthanded, and roundline 3-stranded right-handed. All of the above are used for seizings, but where a heavier and stronger material is needed, a higher grade of stuff is used, laid up by rope-making machinery and finished like the larger sizes of rope, although classed as small-stuff. This is called Seizing Stuff. It is usually 3-stranded, right-handed, and may have 2, 3 or 4 threads to the strand, making 6-thread, 9-thread or 12-thread seizing stuff.

Ratline Stuff does not differ from seizing stuff in its general characteristics, but is larger. It is 3-stranded, right-handed, and may have 4, 5, 6, 7 or 8 threads to the strand, making "12thread," "15-thread," "18-thread" Ratline Stuff, and so on.

Rope-yarns are used for many purposes on board ship, and a good supply of them should always be on hand. They are made from condemned hemp cordage, tarred.

1 wo yarns twisted up together by hand, or single yarns twisted up against their natural lay and rubbed smooth, are called. "foxes" and are often used for light seizings, being much neater than spun-yarn.

For further details as to Cordage, see Appendix.

Rope tends to contract when wet, and unless allowed to do so freely may be injuriously strained. It is for this reason and