Naut. Forms: α. 7 kelsine, kilson, 7– kelson, (9 kelston). β. 7 keeleson, 7– keelson, (8 keelstone, 9 keelsale). [= Du. kolzwijn, kolsem, LG. kielswîn, G. kielschwein, Da. kølsvin, Sw. kölsvin. The first element is app. KEEL sb.1, but of the second the original form and meaning are obscure.
In all the equivalents cited, except Du. kolsem, the second element is identical with the word corresponding to E. swine, and it appears that in 18th c. LG. swîn was used by itself in the sense of ‘keelson’ (see Grimm). The English forms may therefore represent a ME. *kelswīn: cf. the reduction of boatswain to boteson, boson, bos’n. The reason for calling the timber by this name does not appear, but this is also the case with many similar applications of the names of animals, as cat, dog, hog, horse, etc. The original may have been an unrecorded ON. *kjǫlsvín or *kjalsvín, independently adopted in Eng. and LG. The corruptions keelstone, kelston, kelsom, keelsale, originate mainly in the lack of stress on the second element. Eng. stemson and sternson are app. recent formations on the analogy of keelson. It has been suggested that the original form may be preserved in Norw. dial. kjølsvill = ‘keel-sill,’ but this may also be an alteration, by popular etymology, of the usual kjølsvin.
The most usual spelling from the first has been kelson: recently, however, there has been a tendency to spell keelson, though the pron. (ke·lsən) still prevails.]
1. A line of timber placed inside a ship along the floor-timbers and parallel with the keel, to which it is bolted, so as to fasten the floor-timbers and the keel together; a similar bar or combination of iron plates in iron vessels.
α. c. 1611. Chapman, Iliad, I. 426. The top-mast to the kelsine then with halyards down they drew.
a. 1618. Raleigh, Royal Navy, 4. Even from the Batts end to the very Kilson of a Ship.
1637. Heywood, Royall Ship, 44. That one peece of Timber which made the Kel-son.
1711. W. Sutherland, Ship-build. Assist., 26. Bolt the Kelson through every other Floor-timber.
1867. J. Macgregor, Voy. Alone (1868), 6. She has an iron keel and kelson to resist a bump on rocks.
β. 1627. Capt. Smith, Seaman’s Gram., ii. 3. Lay your keeleson ouer your floore timbers, which is another long tree like the keele.
1706. [E. Ward], Wooden World Dissected (1708), 3. Some compare her to a Common-wealth, and carry the Allegory from the Vane down to the Keelson.
1805. Naval Chron., XIV. 172. Placing it on the keelsale.
1840. R. H. Dana, Bef. Mast, xv. 39. Everything has been moved in the hold, from stem to stern, and from the water-ways to the keelson.
1866. Morn. Star, 19 March, 2/1. The ship is built up from a keelson, formed of a huge bar of iron.
fig. 1751. Smollett, Per. Pic., IV. lxxxvii. Something shoots from your arm, through my stowage, to the very keel-stone.
1855. Walt Whitman, Song of Myself, 5. I know … that a kelson of the creation is love.
b. With qualifying terms: assistant kelson or keelson = side-kelson; bilge-k., an additional strengthening beam placed fore-and-aft in the bilge of a vessel, parallel to the kelson; boiler-k., a bilge- or cross-kelson supporting the boilers of a steamer (Hamersly, Naval Encycl., 1881); box-k., a kelson whose section is box-shaped; cross-k., a beam placed across the kelson to support the boilers or engines of a steamer (Webster, 1864); engine-k., a side- or cross-kelson supporting the engines in a steamer (Hamersly, 1881); false k., an additional beam placed longitudinally above the kelson in order to strengthen it (Young, Naut. Dict., 1846); hog k. ? = false kelson; main k., the kelson proper, as distinguished from the side-kelsons, etc.; rider-k., a false kelson, kelson-rider (Knight, Dict. Mech., 1875); side- or sister k., a second kelson parallel with the main one.
1825. Clark, etc. Shipwrights’ Scale Prices, 16. Main, Hog, or Assistant Keelsons. Ibid. All Hog Keelsons under 6 inches thick to be paid plank price.
1859. J. S. Mansfield, in Merc. Marine Mag. (1860), VII. 15. She was strengthened by the addition of two bilge keelsons, having been originally constructed with a keelson and two sister keelsons.
1867. Smyth, Sailor’s Word-bk., s.v. Keelson, The main keelson, in order to fit with more security upon the floor-timbers, is notched opposite to each of them. Ibid., Side-keelsons … First used in mortar-vessels to support the bomb-beds; later they have crept in to support the engines in steamers.
1869. Sir E. J. Reed, Shipbuild., i. 7. A large central box-keelson completed these lower strengthenings.
2. Used as = KEEL sb.1 1. rare.
1831. Capt. Trelawny, Adv. Younger Son, II. 261. I could almost see the kelston as she rolled heavily.
1837. Marryat, Dog-fiend, x. Lowering him down over the bows, and with ropes retaining him exactly in his position under the kelsom, while he is drawn aft by a hauling line until he makes his appearance at the rudder-chains.
3. Comb., as kelson-bolt, -plate; kelson-rider = false kelson (Young, Naut. Dict., 1846).
1825. Clark, etc. Shipwrights’ Scale Prices, 4. Main Keel, exclusive of Shores, Blocks, and Keelson Bolts.
1875. Knight, Dict. Mech., 1223/2. Pigs of iron … laid over the keelson-plates.
