Навигационные предупреждения, передаваемые по радио. Системы navarea, navtex, safety net. Учёт Предупреждений и их использование.

NAVTEX is an international automated  direct-printing service, broadcasting on the single frequency of 518 KHz.

World-wide Navigational Warning Service (WWNWS) The service comprises sixteen geographical sea areas, termed NAVAREAS and identified by Roman numerals. The authority charged with collating and issuing long range radio navigational warnings to cover the whole of an Area is known as an Area Coordinator. The information about transmitting stations coverage is shown in ALRS vol. 3(2). NAVAREA Warnings normally refer only to the area concerned. Within each area they are consecutively numbered throughout the calendar year. They are transmitted at specified times, repeated in the broadcast immediately following the original transmission and thereafter as considered necessary. At least two daily transmission times are considered necessary to provide adequate promulgation. The schedules are designed to avoid coinciding with those of adjacent areas wherever possible. NAVAREA Warnings are transmitted in English and in one or more of the other official languages of the UN as considered necessary. Various modes of emission may be used e.g. radiotelephony, radiotelex, facsimile. Neither the navigational warning signal (2200 Hz tone) nor the safety signal (TTT/Securite) are used to announce NAVAREA Warnings. The transmission facilities include as much of the adjacent areas as can be covered in 24 hours’ sailing by a fast ship (about 700 n miles). Arrangements may be made for warnings to be available at port offices, and, if they remain in force after the last broadcast, the information they contain is  printed and made available worldwide.

NAVAREA Warnings are concerned with information which ocean-going mariners require for safe navigation, including, in particular, failures of important aids to navigation, as well as information which may affect changes to planned navigational routes. The following list, which is not exhaustive, gives types of messages which may be appropriate for transmission as warnings:

(i) Casualties to lights, fog signals and buoys affecting main shipping lanes;

(ii) The presence of dangerous wrecks in or near main shipping lanes and, if relevant, their marking;

(iii) Establishment of major new aids to navigation or significant changes to existing ones when such establishment or change might be misleading to shipping;

(iv) The presence of large unwieldy tows in congested waters;

(v) Drifting mines;

(vi) Areas where search and rescue (SAR) and anti-pollution operations are being carried out (for avoidance of such areas);

(vii) At the request of the controlling MRCC, notification of ships and aircraft on or over the open sea reported in distress, seriously overdue or missing;

(viii) The presence of newly discovered rocks, shoals, reefs and wrecks likely to constitute a danger to shipping, and if relevant, their marking;

(ix) Unexpected alteration or suspension of established routes;

(x) Cable or pipe-laying activities, the towing of large submerged objects for research or geophysical exploration, the employment of manned or unmanned submersibles, or other underwater operations constituting potential dangers in or near shipping lanes;

(xi) Establishment of offshore structures in or near shipping lanes;

(xii) Significant malfunctioning of radio-navigation services;

(xiii) Information concerning special operations which might affect the safety of shipping, sometimes over wide areas, e.g. naval exercises, missile firings, space missions, nuclear tests, etc. It is important what where the degree of hazard is known, this information is included in the relevant warning. Whenever possible, such warnings should be originated not less than five days in advance of the scheduled event. The warning would remain in force until the event is completed.

Within each NAVAREA, Coastal Warnings and Local Warnings may also be transmitted. Coastal Warnings, promulgated by a National Co-ordinator, cover a  region or a portion of the Area and are transmitted through the network of the national coast radio stations. They cover a distance of 100-200 n miles from the coast and are concerned with information which is sufficient  for mariners to know on entering a given Sub-area or Region. Coastal Warnings are broadcast at scheduled times and also on receipt when the urgency demands. They are transmitted in English and in the national language and are broadcast for as long as the information is valid or until it is made available by other means.

Local Warnings cover the area within the limits of jurisdiction of a harbour or port authority and may be issued by  those authorities. They may be issued in the national language only and supplement the Coastal Warnings by giving information not normally required by ocean-going shipping.

NAVTEX and SafetyNET. The GMDSS supports two independent systems for broadcasting MSI (Marine Safety Information): the International NAVTEX and SafetyNET systems. Navigational and meteorological warnings, meteorological forecasts, and other urgent safety-related messages for a given area are generally broadcast over either NAVTEX or SafetyNET. Ships equipped with both a NAVTEX and SafetyNET receiver should select the appropriate receiver to receive MSI for the particular relevant area. Some long range information is also broadcast by HF radiotelex. NAVTEX is generally used for coastal warnings but where a coastal area is not covered by the International NAVTEX service MSI for that area will be broadcast on SafetyNET.

NAVTEX. NAVTEX is an international automated direct-printing service, broadcasting on the single frequency of 518 KHz, for the promulgation of navigational and meteorological warnings and urgent information to ships. It has been developed to provide a low-cost, simple and automated means of receiving maritime safety information on board ships at sea and in coastal waters. The information transmitted is relevant to all sizes and types of vessel and the selective message-rejection feature ensures that every mariner can receive a safety information broadcast which is tailored to his particular needs.

NAVTEX fulfills an integral role in the Global Maritime Distress and Safety System (GMDSS) and is also a component of the World-Wide Navigational Warning Service (WWNWS).

The service uses a single frequency, with transmissions from nominated stations within each NAVAREA being arranged on a time-sharing basis to eliminate mutual interference. All necessary information is contained in each transmission. The power of each transmitter is regulated so as to avoid the possibility of the interference between transmitters.

SafetyNET. The Inmarsat SafetyNET system is used for broadcasts of MSI (Maritime Safety Information) to areas not covered by the NAVTEX system. Operation of the SafetyNET service involves a sequence of events:

1. A registered Information Provider, such as a National Hydrographic Office, Rescue Coordination Centre (RCC), or Meteorological Office, receives information from its specialized sources.

2. Each Information Provider prepares an MSI message in a standardized format, and submits it to the appropriate coordinator (Navigational Warning Coordinator, SAR Coordinator, or Meteorological Issuing Service)

3. The coordinator checks the message with any other information received, and edits it accordingly, then submits the finalized text to a selected Inmarsat-C CES (Coast Earth Station).

4. The Information Provider may also choose the scheduled time(s) at which the message is to be broadcast, and, if a CES operates in more than one Ocean Region, the satellite to be used.

5. The CES receives the message with its instructions, and queues it with any other messages received, according to priority and scheduled time of transmission.

6. At the required time of transmission, the CES forwards the message over the Interstation Signalling Link (ISL) to the NCS (Network Coordination Station) for the Ocean Region.

7. The NCS automatically broadcasts the message on the NCS Common Signalling Channel over the entire Ocean Region.

8. All EGC (Enhanced Group Call) receivers will receive the MSI message, and print it out, unless the operator has chosen to reject messages of that type, or it has recently been printed out by that terminal.

MSI broadcast over the SafetyNET service:

Coastal Warnings (to areas where NAVTEX MSI is not provided)

· Navigational warnings;

· Meteorological Warnings;

· Ice reports;

· Search and rescue information;

· Meteorological forecasts;

· Pilot service messages;

· LORAN system messages;

· SATNAV system messages;

· Other electronic navaid messages;

· Additional navigational warnings.

Meteorological and Navarea warnings and meteorological forecasts to ships with specified NAVAREAs/METAREAs.

Search and rescue coordination to fixed areas.

Search and rescue coordination to ships within specified circular areas.

Urgency messages, meteorological and navigational warnings to ships within specified areas.

Shore-to-ship distress alerts  to ships within specified areas.

Urgency messages and navigational warnings to ships within specified rectangular areas.

Chart correction service (being developed).

Требования ИМО к форме и содержанию судовой информации о маневренных свойствах судна. Лоцманская карточка.

Маневренные характеристики определяются после постройки, модернизации или в процессе эксплуатации судна. Работу эту выполняют  испытательная партия завода, специалисты, направленные на судно или судоводительский состав.

Для определения маневренных элементов используют натурные, натурно-расчётные и расчётные методы, точность которых, определяемая по внутренней сходимости (для натурных методов) или путём сравнения с натурными данными (для расчётных методов), не хуже ±10% от средней величины определяемого параметра (СКП).

Для однотипных судов можно использовать осреднённые значения маневренных элементов, полученные в результате испытаний отдельных судов этой серии, при условии, что контрольные определения не отличаются от средних боле чем на 10% (СКП).

Маневренные элементы судна определяются на мерной линии, радиолокационном или специальном полигоне, а также в любом районе, где возможны определения места судна достаточной точности. Стандартными условиями испытаний являются: глубина моря − не менне шести средних осадок судна, скорость ветра до  8 м/с, состояние поверхности моря до 3 баллов, отсутствие заметных течений.

Информация о маневренных характеристиках должна представляться в виде:

♠ лоцманской карточки;

♠ таблицы маневренных характеристик (для рулевой рубки);

♠ формуляра маневренных характеристик.

В информацию о маневренных характеристиках должны вноситься изменения после модернизации или переоборудования судна, в результате которых могут измениться мневренные характеристики или наибольшие размерения судна.

Лоцманская карточка заполняется капитаном и предназначается для того, чтобы обеспечить информацией лоцмана, принимающего судно под проводку. В лоцманской карточке приводится следующая информация: дата, название судна, позывной, дедвейт, год постройки, осадки кормой и носом, водоизмещение, LOA и BOA, наличие бульбовой наделки, длина якорных цепей, схематическое изображение судна с указанием основных размерений, тип и мощность двигателя, таблица скоростей и частот  вращения, наличие подруливающего устройства (мощность), характерисики рулевого устройства (тип, время перекладки с борта на борт, макс. угол перекладки), чеклист готовности судовых механизмов и навигационных приборов. Для заполненеия лоцманской карточки провдение специальных испытаний не требуется.

Таблица маневренных характеристик должна содержать особенности и подробную информацию о маневренных характеристиках судна и должна быть таких размеров, чтобы ей было удобно пользоваться. Маневренные характеристики судна могут отличаться от табличных из-за влияния внешних условий, состояния корпуса и загрузки судна.

Формуляр маневренных характеристик должен содержать достаточно подробное описание маневренных характеристик судна и другие соответствующие данные, в т.ч. содержащиеся в таблице маневренных характеристик. Большая часть приводимых в формуляре данных может быть рассчитана, однако некоторая часть должна быть получена  на испытаниях. Информация в формуляре может пополняться в течение срока эксплуатции судна.

На судах с незначительным изменением осадки (пассажирских, гидрографических и пр.) информация о маневренных харатеристиках представляется для одного среднего водоизмещения судна.