Image above, Boiler Room Orders Telegraph - These telegraphs, installed in every stokehold, allowed the Engineer at the Starting Platform to communicate changes in speed to the Junior Engineering Officer on watch in every stokehold. This would be done in advance of the Bridge actually ringing down the change in revolutions, in order that the stokehold crew would know in advance whether they would need to increase or decrease the rate at which steam was being produced. The Shipbuilder / Author’s collection

   Engine and steering telegraphs - Located on the Navigating Bridge, the Docking Bridge and in the Reciprocating Engine Room were a series of telegraphs. These devices were made by J. W. Ray & Co., Liverpool, and were each fitted with double 24"-diameter dials. Each telegraph had two handles, one on each side of the dial drum. These handles worked independently of each other, and were not connected. On the Navigating Bridge were five telegraphs, three on the port side and two on the starboard side. Three of the telegraphs - the outermost one on each side, plus the one immediately to port of the wheel - were called “engine order telegraphs,” and were linked to indicator telegraphs in the Engine Room, instruments which were used to receive and acknowledge these orders. Each engine order telegraph was fitted so that its starboard handle sent orders for the starboard reciprocating engine, and the port handle, for the port engine . . . (continued)

   Navigation and position plotting - the landsman with a limited knowledge of navigation often assumes that a ship’s position at sea is determined by “shooting the sun” with a sextant. While this method was used during daylight hours, the position of the sun by itself would not yield a position of any great accuracy. A single observation of any heavenly body (including the sun) yielded only a position line on which the ship was ostensibly located. Because of the need to triangulate a position based on a multiple number of heavenly bodies, the ship’s position was not precisely known during the daylight hours. The only relatively accurate positions were obtained in the morning and evening by observing three or more stars and/or planets in quick succession. This was done when it was dark enough to see the stars but light enough to see the horizon. A position line was obtained from each celestial body and corrections applied to allow for the ship’s movement between sights. The ship’s position was at the intersection of the three best lines or, if the lines did not all intersect at the same point on the chart, within the small triangle formed by their near intersection . . . (continued)

   Whistles - The types of whistles in use in 1912 were the organ, dome, and siren. An organ whistle such as was mounted on the Lusitania gave a strong, loud note, but the range of audibility was not as great as that of the dome type fitted to Titanic. For a dome whistle, the note produced depended on the length of the vibrating column - i.e., the length of whistle - and the pressure of steam. Adjustment of the dome variety was accomplished by screwing the bell up or down on a central spindle. To obtain a greater volume of sound, three whistles of different notes (different dome sizes) were arranged on the same branch piece, with a common control valve . . . (continued)

   House flag - Titanic was rigged with two sets of halyards at each mast, each of which ran through sheaves in the truck of the teak pole at the top of the mast. The WSL house flag was always flown at the main (mainmast), as was customary with merchant ships. A house flag, along with the funnel colors, identified a ship as belonging to a particular shipping line. The practice of flying a unique owner’s flag dates to the late 1700s, but the practice originated as a means of signaling the ship’s arrival to its owners rather than to identify the shipping line to others. By the mid-1800s, though, there were very few shipping lines that could not be readily identified by their own unique flags, and in 1882 the first edition of Lloyd’s Book of House Flags was published . . . (continued)

   Pyrotechnic and rocket signals - Most routine signaling at night would be accomplished by means of electric Morse lamps, but Titanic carried a full range of pyrotechnic and rocket signals in the number and pattern approved by the Board of Trade - e.g., 12 ordinary rockets, 36 socket signals in lieu of guns, 2 Manwell-Holmes deck flares, 12 blue lights (Roman Candles), and 6 lifebuoy lights. Any mention of night signals must include a discussion of the rockets: they were specific in their characteristics, were used on the morning of April 15 by Titanic, and their display was tragically misunderstood . . . (continued)