A signal station is a form of Aids to Navigation that is defined by the IHO simply as "A signal station is a place on shore from which signals are made to ships at sea". [1] While this broad definition would include coastal radio stations and fog signal stations, the term is most often used for shore installation that use visual signals to communicate with ships at sea.
Signal stations were the only practical mean of communicating with passing ships until the development of radio, and played a critical role in both navigation safety and commercial operation of fleets. As they were normally located in high places with extensive fields of view, surviving signal stations are often in scenic locations, and have become local landmarks.
Signal stations used a variety of means to communicate shore-to-ship: Chappe Telegraph or other forms of pole-and-arm optical telegraph, [2] flag semaphore, heliograph, slat semaphore, and port-specific signals (like flag and ball weather warnings). [3] The most widespread method was through different forms of flaghoist. Signals were often private signals, requiring local knowledge or code books.
From the 1880s, Lloyd's operated a network of signal stations around the world, [4] connected to telegraph land-lines, that served to relay orders from owners and obtain reports from ships' masters. Messages for passengers could also be sent using a flag semaphore, and light signals at night. [5]
While radio has superseded the telegraph-relay role of signal stations, a number of signal stations remain in operation in situations where static visual signals provide fast access to specific safety information, such as traffic signalling in ports and narrow passages, or navigational warnings. In Japan, signal stations in the form of lighted letter boards are extensively used to mark traffic conditions, one way flows and predominant currents. [6] Most ports elsewhere in the world will use a form of the International Port Traffic Signals system. [7]
Tide gauges are usually classified as signal stations, as they provide immediate visual information of tide levels.
Telegraphy is the long-distance transmission of messages where the sender uses symbolic codes, known to the recipient, rather than a physical exchange of an object bearing the message. Thus flag semaphore is a method of telegraphy, whereas pigeon post is not. Ancient signalling systems, although sometimes quite extensive and sophisticated as in China, were generally not capable of transmitting arbitrary text messages. Possible messages were fixed and predetermined, so such systems are thus not true telegraphs.
SOS is a Morse code distress signal, used internationally, originally established for maritime use. In formal notation SOS is written with an overscore line, to indicate that the Morse code equivalents for the individual letters of "SOS" are transmitted as an unbroken sequence of three dots / three dashes / three dots, with no spaces between the letters. In International Morse Code three dots form the letter "S" and three dashes make the letter "O", so "S O S" became a common way to remember the order of the dots and dashes. IWB, VZE, 3B, and V7 form equivalent sequences, but traditionally SOS is the easiest to remember.
An optical telegraph is a line of stations, typically towers, for the purpose of conveying textual information by means of visual signals. There are two main types of such systems; the semaphore telegraph which uses pivoted indicator arms and conveys information according to the direction the indicators point, and the shutter telegraph which uses panels that can be rotated to block or pass the light from the sky behind to convey information.
Optical communication, also known as optical telecommunication, is communication at a distance using light to carry information. It can be performed visually or by using electronic devices. The earliest basic forms of optical communication date back several millennia, while the earliest electrical device created to do so was the photophone, invented in 1880.
A distress signal, also known as a distress call, is an internationally recognized means for obtaining help. Distress signals are communicated by transmitting radio signals, displaying a visually observable item or illumination, or making a sound audible from a distance.
Marine VHF radio is a worldwide system of two way radio transceivers on ships and watercraft used for bidirectional voice communication from ship-to-ship, ship-to-shore, and in certain circumstances ship-to-aircraft. It uses FM channels in the very high frequency (VHF) radio band in the frequency range between 156 and 174 MHz, designated by the International Telecommunication Union as the VHF maritime mobile band. In some countries additional channels are used, such as the L and F channels for leisure and fishing vessels in the Nordic countries. Transmitter power is limited to 25 watts, giving them a range of about 100 kilometres.
From early in the 20th century, the radio frequency of 500 kilohertz (500 kHz) was an international calling and distress frequency for Morse code maritime communication. For much of its early history, this frequency was referred to by its equivalent wavelength, 600 meters, or, using the earlier frequency unit name, 500 kilocycles or 500 kc.
The automatic identification system (AIS) is an automatic tracking system that uses transceivers on ships and is used by vessel traffic services (VTS). When satellites are used to receive AIS signatures, the term Satellite-AIS (S-AIS) is used. AIS information supplements marine radar, which continues to be the primary method of collision avoidance for water transport. Although technically and operationally distinct, the ADS-B system is analogous to AIS and performs a similar function for aircraft.
A chief mate (C/M) or chief officer, usually also synonymous with the first mate or first officer, is a licensed mariner and head of the deck department of a merchant ship. The chief mate is customarily a watchstander and is in charge of the ship's cargo and deck crew. The actual title used will vary by ship's employment, by type of ship, by nationality, and by trade: for instance, chief mate is not usually used in the Commonwealth, although chief officer and first mate are; on passenger ships, the first officer may be a separate position from that of the chief officer that is junior to the latter.
A second mate or second officer (2/O) is a licensed member of the deck department of a merchant ship holding a Second Mates Certificate of Competence, by an authorised governing state of the International Maritime Organization (IMO). The second mate is the third in command and a watchkeeping officer, customarily the ship's navigator. Other duties vary, but the second mate is often the medical officer and in charge of maintaining distress signaling equipment. On oil tankers, the second mate usually assists the chief mate with the cargo operations.
Military communications or military signals involve all aspects of communications, or conveyance of information, by armed forces. Examples from Jane's Military Communications include text, audio, facsimile, tactical ground-based communications, naval signalling, terrestrial microwave, tropospheric scatter, satellite communications systems and equipment, surveillance and signal analysis, security, direction finding and jamming. The most urgent purposes are to communicate information to commanders and orders from them.
The International Code of Signals (INTERCO) is an international system of signals and codes for use by vessels to communicate important messages regarding safety of navigation and related matters. Signals can be sent by flaghoist, signal lamp ("blinker"), flag semaphore, radiotelegraphy, and radiotelephony. The International Code is the most recent evolution of a wide variety of maritime flag signalling systems.
Semaphore is a northwestern suburb of Adelaide in the Australian state of South Australia. It is located on the Gulf St Vincent coastline of the Lefevre Peninsula about 14 kilometres (8.7 mi) from the Adelaide city centre.
Flag semaphore is a semaphore system conveying information at a distance by means of visual signals with hand-held flags, rods, disks, paddles, or occasionally bare or gloved hands. Information is encoded by the position of the flags; it is read when the flag is in a fixed position. Semaphores were adopted and widely used in the maritime world in the 19th century. It is still used during underway replenishment at sea and is acceptable for emergency communication in daylight or using lighted wands instead of flags, at night.
Bass Point is a headland on the coast of Cornwall, England. It is at the southern tip of the Lizard peninsula, in the civil parish of Landewednack. The headland was a communications centre during the Victorian era, with the Lloyds Signal Station, opened in 1872 for shore to ship communications, and Marconi's experiments with wireless at the Lizard Wireless Station.
Semaphore is the use of an apparatus to create a visual signal transmitted over distance. A semaphore can be performed with devices including: fire, lights, flags, sunlight, and moving arms. Semaphores can be used for telegraphy when arranged in visually connected networks, or for traffic signalling such as in railway systems, or traffic lights in cities.
The Port of Tianjin falls under the supervisory and regulatory purview of the Tianjin Municipality People’s Government. The 2004 incorporation of the Tianjin Port Authority into TPG formally divested the group of its role as Port Regulator, which passed to the Tianjin Transportation and Port Authority (天津市交通运输和港口管理局), formerly the Tianjin Transport Commission. The TTPA implements state policy on port work; drafts local policies, by-laws and regulations; and licenses, audits, and issues certifications to businesses operating in the port, in particular to ship terminals. The TTPA supervises and manages compliance to all laws and regulations regarding environmental protection, service compliance, pilotage, maintenance of port infrastructure and handling of dangerous goods and disinfection in all terminals and storage areas.
The Directorate General of Coastal Safety has been established by the Turkish Republic Council Of Ministers’ decision on 12 May 1997 as a General Directorate and State owned Organization. The mission of the foundation is to assist and improve the safety of navigation in Turkish Waters. The organization’s core competences are:
Submarine signals had a specific, even proprietary, meaning in the early 20th century. It applied to a navigation aid system developed, patented and produced by the Submarine Signal Company of Boston. The company produced submarine acoustic signals, first bells and receivers then transducers, as aids to navigation. The signals were fixed, associated with lights and other fixed aids, or installed aboard ships enabling warning of fixed hazards or signaling between ships. ATLAS-Werke, at the time Norddeutsche Maschinen und Armaturenfabrik, of Germany also manufactured the equipment under license largely for the European market.