The Seaman's Friend Part 1

The Seaman's Friend.

by Richard Henry Dana.

PART I.

CHAPTER I.

GENERAL RULES AND OBSERVATIONS.

Construction of vessels. Tonnage and carriage of merchant vessels.

Proportions of the spars. Placing the masts. Size of anchors and cables. Lead-lines. Log-line. Ballast and lading.

CONSTRUCTION OF VESSELS.--As merchant vessels of the larger cla.s.s are now built in the United States, the extreme length of deck, from the after part of the stern-post to the fore part of the stem, is from four and a half to four and three fourths that of the beam, at its widest part. The Damascus, of 700 tons' measurement, built at Boston in 1839, and considered a fair specimen of our best freighting vessels, had 150 feet from stem to stern-post, and 32 feet 6 inches extreme breadth. The Rajah, of 530 tons, built at Boston in 1837, had 140 feet length, and 30 feet beam;--being each in length about four and six tenths their beam.

A great contrast to this proportion is exhibited in the most recent statistics (1841) of vessels of the same tonnage in the English navy; as the following table will show.

Tons. Deck. Beam. Proportion.

{Dido 734 120 ft. 37 ft. 6 in. 3.20 English {Pilot 492 105 33 6 3.13 Navy. {Alert 358 95 30 4 3.16

American {Damascus 694 150 32 6 4.60 Merchantmen. {Rajah 531 140 30 0 4.66

These may, perhaps, be considered the extremes of s.h.i.+p-building; and between these there is every grade of difference.

TONNAGE AND CARRIAGE OF MERCHANT VESSELS.--The amount a vessel will carry in proportion to her tonnage, depends upon whether, and to what extent, she is full or sharp built. A sharp-built vessel of 300 tons'

measurement, will carry just about her tonnage of measurement goods. A sharp-built vessel of 200 tons or under would probably carry less than her measurement; if over 400 tons, she would increase gradually to fifty per cent. above her measurement. A sharp-built vessel of 600 tons, is generally rated at 900 tons carriage. A full-built vessel of 300 tons, after the latest model of American freighting vessels, will carry 525 tons, or seventy-five per cent. above her measurement; and one of 500 tons would carry full double her measurement.

The following table may give a pretty fair average.

TONS OF MEASUREMENT GOODS.

Tonnage. Full built. Sharp built.

300 (.75) 525 (.00) 300 400 (.80) 725 (.40) 560 500 (1.00) 1000 (.50) 750 600 (1.33) 1400 (.50) 900

PROPORTIONS OF SPARS.--There is no particular rule for sparring merchant vessels; some being light, and others heavy sparred; and some having long topmasts and short lower masts, and others the reverse. The prevailing custom now is, to spar them lightly; the main yard being a little less than double the beam; and the others proportioned by the main. Most merchant vessels now have the yards at the fore and main of the same size, for convenience in s.h.i.+fting sails; so that the same topsail may be bent on either yard.

The following table, taken from the "Seamen's Manual," will show the average proportions of the spars of merchant vessels of the largest cla.s.s, as formerly built.

Main-mast, two and a half times the s.h.i.+p's beam.

Fore-mast, eight ninths of the main-mast.

Mizzen-mast, five sixths of the main-mast.

Bowsprit, two thirds of the main-mast.

Topmasts, three fifths of the lower masts.

Topgallant masts, one half the length of their topmasts.

Jib-boom, the length of the bowsprit.

Main-yard, twice the beam.

Fore-yard, seven eighths of the main-yard.

Maintopsail-yard, two thirds of the main-yard.

Foretopsail-yard, two thirds of the fore-yard.

Crossjack-yard, the length of the maintopsail-yard.

Topgallant-yards, two thirds of the topsail-yards.

Mizzentopsail-yard, the length of the maintopgallant-yard.

Royal-yards, two thirds of the topgallant-yards.

Spritsail-yard, five sixths of the foretopsail-yard.

Spanker-boom, the length of the maintopsail-yard.

Spanker-gaff, two thirds of the boom.

For the thickness of the spars, the same book allows for the lower masts one inch and a quarter diameter at the partners, for every three feet of length; and nine tenths in the middle and two thirds under the hounds, for every inch at the partners. For the yards, one inch at the slings, and half an inch at the yard-arms, within the squares, for every four feet of the length. For the breadth of the maintop, one half of the beam, and of the foretop, eight ninths of the maintop.

The following are the proportions of the spars of the s.h.i.+p Damascus, before mentioned, built in 1839.

Main-mast 74 ft. Head 11 ft. 6 in. Size 26 in.

Fore-mast 70 ft. Head 11 ft. 6 in. Size 25 in.

Mizzen-mast 68 ft. Head 8 ft. 6 in. Size 18 in.

Main and fore topmasts 41 ft. Head 6 ft. 6 in. Size 14-1/2 in.

Mizzen topmast 32 ft. Head 5 ft. Size 9-1/2 in.

Main topgallant-mast 23 ft. (15 ft. with 2 feet head.) Size 9-1/2 in.

Fore topgallant-mast 21 ft. 14 ft. with 2 feet head.) Size 9-1/2 in.

Mizzen topgallant-mast 17 ft. 11 ft. with 18 in. with 2 feet head.) Main and fore yards 60 ft. yard-arms 2 ft. 6 in.

Main and fore topsail yards 48 ft. yard-arms 3 ft. 6 in.

Main topgallant yard 37 ft. yard-arms 2 ft.

Fore topgallant yard 34 ft. yard-arms 2 ft.

Main royal yard 27 ft. yard-arms 1 ft. 6 in.

Fore royal yard 24 ft. yard-arms 1 ft. 6 in.

Main skysail yard 17 ft.

Fore skysail yard 15 ft.

Cross-jack yard 44 ft. yard-arms 2 ft.

Mizzen topsail yard 35 ft. yard-arms 2 ft. 9 in.

Mizzen topgallant yard 25 ft. yard-arms 1 ft. 6 in.

Mizzen royal yard 16 ft.

Mizzen skysail yard 10 ft.

Bowsprit, out-board 27 ft. Size 26 in.

Jib-boom 42 ft. Head 3 ft. Size 14-1/2 in.

Flying jib-boom 40 ft. Head 3 ft. 6 in.

Main pole 12 ft., 10 above royal-mast, 5 in. in cap.

Fore pole 11 ft., 9 above royal-mast, 4-1/2 in. in cap.

Mizzen pole 9 ft., 7 above royal-mast Spanker-boom 40 ft.

Spanker-gaff 30 ft.

Swinging-booms 40 ft.

Topmast studdingsail-booms 34 ft.

Topgallant studdingsail-booms 27 ft., yards for do. 17 ft.

PLACING THE MASTS.--For a full-built s.h.i.+p, take the s.h.i.+p's extreme length and divide it into sevenths. Place the foremast one seventh of this length from the stem; the mainmast three sevenths from the foremast, and the mizzenmast two sevenths from the mainmast. If a vessel is sharp-built, and her stem and stern-post rake, her foremast should be further aft, and her mizzenmast further forward, than the rule of sevenths would give. A common rule for placing the foremast, is to deduct three fifths of a s.h.i.+p's beam from her length, for the curvature of the keel forward, which is called the _keel-stroke_, and place the mast next abaft the keel-stroke.

SIZE OF ANCHORS AND CABLES.--Various rules have been adopted for the weight of a s.h.i.+p's anchors. A vessel of 100 tons will generally have a best bower of 6 cwt. and a small bower of 5 cwt.; the weight of both being eleven pounds to a ton of the vessel. As a vessel increases in size, the proportion diminishes. A vessel of 700 tons will usually carry a best bower of 27 cwt. and a small bower of 24 cwt.; the weight of both being seven and a half pounds to a ton of the vessel. The _stream_ should be a little more than one third the weight of the best bower. The anchor-stock should be the length of the shank; its diameter should be half that of the ring, and its thickness one inch at the middle and half an inch at each end for every foot in length. Chain cables are usually ninety fathoms in length, for large-sized vessels, and sixty for small vessels, as schooners and sloops. The regulation of the United States Navy for chain cables, is one inch and a half for a sloop of war, and one and a quarter for brigs and schooners. In the merchant service, a s.h.i.+p of 400 tons would probably have a best bower cable of one and five sixths, and a working bower of one and a quarter inches. A s.h.i.+p of 700 tons would have a best bower of one and five eighths, and a working bower of one and a half inches. Chain cables have a shackle at every fifteen fathoms, and one swivel at the first shackle. Some have two swivels; and formerly they were made with a swivel between each shackle.