How wire replaced fiber rope for riggingJan 1, 2003
|From Ocean Navigator #84 |
When the tables were compiled, the USS Pennsylvania, a 120-gun, three-deck Ship of the Line, was the largest vessel in commission. Rigging her required 70,685 feet of hemp rope (13.4 miles). In addition, she was expected to go to sea with 81,120 feet of manila clothes lines, 6,400 feet of hammock girt-lines, and 864 feet of hammock tricing lines. A small amount of leather was thrown into the mix for topsail ties, truss pendants, and reef pendants.
The rigging also contained a good quantity of iron in the form of chain, bar, or plate. The bobstay, bowsprit shrouds, gammoning, martingale stays, martingale guys, bumkin braces, shank painter, cat-stoppers, fore and main yard slings, cross-jack yard slings, topsail slings, and a more than a dozen other fittings were all formed of that metal. However, not a single inch of wire rope appears in the Kedge-Anchor's tables, nor is there a reference to it anywhere in the 400 pages of text. In 1847, as far as the Navy was concerned, wire rope did not exist. That judgment was not quite accurate.
The Navy in 1847, as well as the marine industry in general, was not quite certain about the use of iron in any form. Not even the ground tackle of a three-decker was completely reliant on iron chain. Roughly half the anchor cables were hemp despite the fact that the weight-to-strength advantage of iron was well known and appeared in tabular form in The Kedge-Anchor.
In 1851 A New Rig for Ships and other Vessels Combining Economy, Safety, and Convenience was published in Boston. Its author, R.B. Forbes, had no reservations about the use of iron rigging.
"I will not undertake to advocate any particular kind of rope where most of the rope in use is good enough; but I have a word to say on the manner of using it," Forbes wrote.
"The Massachusetts, Samoset, Reindeer, and others have iron plates and bands, to which the lower rigging is attached at the mast-heads. They have had the experience of several years; and I have not only heard no complaint of this mode of fitting lower rigging, but I find it is much approved of. The ship Great Britain's rigging is also fitted to bands, but so clumsily done that I should condemn it if the rigging would answer to fit in the usual way.
"The advantages of this mode, as applied by me, are, first, there is much less chance for slack rigging, less liability to rot the mast-heads and the rigging itself, less wear and tear and chafing; the rigging can be sent down easily at sea or in port, two shrouds at a time, for repairs; the parts bear more equally than in the ordinary mode; and lastly, the rigging looks snugger. The objection generally made to the plan is, 'I don't like to trust iron aloft:' which objection is met by the simple question,Why is not iron as strong up there as at the lower end, where you trust to the dead eye strap, and chain plate of iron? It is true, that, if you carry away any, you necessarily derange two shrouds, instead of one; but the liability to carry any away is so much less, that this objection amounts to little. We put iron now in many places subject to violent and sudden strains with entire confidence, as bobstays, gammoning, trusses, pareils, &c.; why not the standing rigging?"
Forbes' primary interest was rigging and particularly in the use of iron, which he saw as a significant advance.
The employment of iron as a structural element occurred in bridge building decades before thought was given to any marine application other than anchor chain. Ironically, it was anchor chain that permitted the construction of the first substantial suspension bridges.
Some uncelebrated genius in the north of England used anchor chain to construct a suspension bridge in 1741. Its physical span was a mere 39 feet. Its conceptual impact was immeasurable.
In the United States alone, some 40 chain suspension bridges were constructed between 1800 and 1820. By 1810 the manufacture of chain intended for use in bridge building was well established in England under the proprietorship of Capt. Samuel Brown of the Royal Navy. Chain, however, had its shortcomings, and iron eyebars soon began to replace chain in new bridge construction. In 1820 Brown built a suspension bridge across the River Tweed near Berwick, England, using circular eyebar suspension chain. The bridge, and its original components, is still in use.
But iron, whether chain or eyebar, presented problems to the builders of suspension bridges who were looking for maximum flexibility and minimum weight without loss of strength. The answer was wire cable.
The first use of wire cable in bridge construction was at Fribourg, Switzerland, in 1834. The composition of early 19th century wire cable varied. One formulation called for 278 wires to be twisted into a single strand; 19 strands to be twisted around a core of soft iron wire to form a single cable. The number of cables required to support the weight of a bridge also varied greatly. In the construction of the Brooklyn Bridge (which employed steel, not iron) the main cables were composed of 25 cables twisted into a specific pattern. Chain and eyebars did not immediately give way to cable, but that change was not long in coming.
Even before the first edition of The Kedge-Anchor went into circulation, at least two wire rope manufacturing facilities had been established in the United States. In Pittsburgh, John A. Roebling, designer of the Brooklyn Bridge, had been turning out commercial quantities of wire rope for several years. In 1845 he employed wire rope in the construction of a suspension aqueduct over the Allegheny River. In Mauch Chunk, Pa., the Hazard Wire Rope Works opened its doors in 1846. Both facilities considered bridge building their primary market.
When was wire rope first used in the rigging of ships? The date is unclear. According to Forbes it was no later than 1851. And using The Kedge Anchor as an indicator, it was probably no earlier than 1847. The corporate records of the Hazard Wire Rope Works (later to do business as the Hazard Wire Rope Division of the American Chain and Cable Company) pointtoward1847asthestartingdate.
Whatever the year, by the 1880s wire rigging was sufficiently well established to be carried regularly by major marine suppliers. In its 1888 catalog, Merwin, Hulbert & Co. (New York City) offered six sizes of wire rope, tinned or galvanized, ranging from inch to inch. It was steel wire, however, not iron, an advance made possible by the use of steel wire in the construction of the Brooklyn Bridge five years earlier. By 1898, L.W. Ferdinand & Co. (Boston) not only listed 23 sizes of wire rope in its catalog but included clamps, stay cleats, and thimbles as well as a wire rope splicing service"Wire Ropes spliced and made endless." The Ferdinand catalog, incidentally, referred to wire rope as "charcoal rope." Within a decade, the Topping Brothers' (New York City) catalog had added eye blocks, cheek blocks, clips, sheaves, and sockets to the list of products specifically intended for use with wire rope.
Working with wire rope presented a challenge for riggers long accustomed to handling hemp and manila. In 1893, the seventh edition of The Rigger's Guide & Seaman's Assistant addressed the problem in a section that covered "Directions to Measure for Lower Rigging," "Cutting Out Wire Rigging," and "Fitting Wire Rigging." A few years later, in 1898, The Boat Sailor's Manual took two pages (out of 265) to explain wire rope splicing to the amateur.
By the turn of the century there was no question that hemp standing rigging was on its way out.
In 1902 the 5,081-gross ton Preussen (Prussian), arguably the most powerful sailing vessel ever built, was launched. She was 407.8 feet overall, had a 53.6-foot beam, drew 27 feet and was fast enough to outdistance all but the swiftest liners. A full-rigged ship, her five towering steel masts carried 60,000 square feet of canvas.
Her rigging requirements were almost double those of USS Pennsylvania: wire standing rigging, 35,424 feet; wiring running rigging, 43,394 feet; chain, 2,296 feet. The only hemp on board was used as running rigging, 56,613 feet of it.
After only a few years of service the Preussen was rammed in the Strait of Dover by a Channel steamer that holed her steel hull and sent her to the bottom.
Industrial hemp suffered a corresponding fate in the 1930s when the Uniform Narcotic Act and the Marijuana Tax Act torpedoed further cultivation in this country. There is now a movement to legalize it again. Even though its use as rope aboard ship is undoubtedly a thing of the past, hemp may go to sea once more as fabric (particularly canvas) and oakum, which is used for caulking wooden hulls. Hemp hats, shirts, shoes, socks, wallets, field bags, duffels, and attachÃ© cases are already available via mail order. A store in New York City sells hemp pillowcases, napkins, tablecloths, and curtains. Hemp also can be used in paints, paper, cordage and oils, both edible and inedible. None of these products would come as news to our forefathers. The Declaration of Independence was drafted on hemp paper and Betsy Ross's flag was made of hemp fabric.
But what about its psychoactive component? Although both are members in good standing of the family Cannabis sativa, marijuana and hemp are actually distant cousins, marijuana being at least 10 times more potent. Something to contemplate the next time you're high in the rigging.
Michael Neyer, who writes often on marine historical topics, is a freelance writer and sailor living in Roslyn N.Y.