Patent GB-190907904-A (GB)
Title: Improvements in or relating to Apparatus for Towing Ships.
Inventor: FROGER LOUIS VICTOR WILLIAM
IPC: B63B21/56
Filed: 1909-04-02
Granted: 1909-09-09
Abstract: 7904. Froger, L. V. W. April 2. [Addition to 10,926/08.] Towing. - Relates to various improvements in ships' towing - apparatus of the kind described in the parent Specification, wherein is employed an endless tow-line passing around two pulleys rotatably mounted on bitts, one on the tug and one on the ship to be towed. In the construction of bitt shown in Figs. 7 and 8, a bedplate 4 and counter-plate 2 are secured to the deck 1, and the bitt proper 5 is provided with a squared part 10 passing therethrough, a securing-nut 6 engaging its lower end. A grooved pulley-sheave 7, around which the pendant 3 of the endless towline passes, is arranged between the plate 4 and a flange on the upper end of the bitt 5, ball bearings being provided at 8, 9. The bed-plate 4 and the upper flange of the bitt 5 are each provided with two lateral lugs 11, which form stops for projections 12 secured to the pendants 3 for the purpose of limiting their movement on the bittpulleys. The bitt-pulley 7 may be mounted at the base of the mast 13, Fig. 9, and held in place by a flanged collar 16 secured to a hub portion 14 of the bed-plate 4. An improved construction of shackle for connecting the two pendants 3 to the intermediate portions of the tow-line is shown in Fig. 3. A stirrup 22 carries a bolt 23 provided with a finger 24, which is adapted to engage a bent ring 21, its free end entering a laterally-slotted socket 25, which is secured to a rod 26 rotatably mounted in a crossbar 28. In order to release the finger 24 from the socket 25, the rod 26 is rotated by means of a nut 29 and a spanner, and the bolt 23 can then be rotated by means of a nut 30 and a spanner 32, thus allowing the disengagement of the bent ring 21 from the finger 24. In the arrangement shown in Fig. 13, the endless tow-line is passed around four lateral bitt-pulleys, two on each ship, so that it does not sweep the decks. A stop-lug 11 is provided on one side only of the pulleys. The spanners for effecting the disengagement of the fingers 24, Fig. 3, of the shackles may be operated by means of a cord 35, Fig. 13, a cable 37 passing through eyes 38, and a pulley tackle 40 adapted to put tension on the cord 35. Alternatively the shackles may be operated by means of endless chains passing around toothed pulleys. The endless tow-line may be passed around three pulleys, one on one ship and two on the other. In the arrangement shown in Fig. 20, particularly designed for towing off stranded vessels, four endless tow-lines are employed. One of these passes around two lateral pulleys 52 on each ship, each of which pulleys is suspended by shackles and chain links from a lug 45 secured to the side of the ship. Another towline passes around a pulley 54 on each ship, this pulley being suspended by shackles and chain links from a two-part collar 58 surrounding the base of the mast 55. When it is desired to use a ship either as a tug or a vessel to be towed, a central pulley or two lateral pulleys may be arranged in a vertical plane passing through the centre of gravity of the ship, and the pendant of the tow-line is directed from them towards the stern or bow as required, the stop-lugs 11 being duplicated. Bitts of the usual kind, whether single or double, may be adapted for use with an endless tow-line by surrounding them with metal casings.