Section 6: Navigation and Communications

Melville is equipped with an extensive suite of navigation and communications instruments and devices. This equipment allows precise navigation and control of the ship and worldwide communications in voice, data and facsimile. A number of the more prominent systems and devices are listed below and described. Where commercial services are engaged, the particular user will be responsible for any charges incurred. Please see our communication sheet for current InMarsat numbers.

AMATEUR RADIO (HAM) - It is possible for licensed amateur radio operators to bring equipment aboard. Operation of HAM equipment must not interfere with other ship operations. Individuals wishing to set up HAM equipment must secure approval from the captain and chief scientist prior to departure.

CELLULAR TELEPHONE SYSTEM - Melville is not equipped with a cellular telephone as she normally operates beyond the range of cellular systems. When the vessel operates in coastal U.S. waters a portable unit may be carried. On the high seas voice communications are normally conducted in the ship's radio room using satellite or terrestrial systems. (See appropriate sections below.)

DATA COMMUNICATIONS - One terrestrial and two satellite systems are available for the transmission and receipt of data and text messages. The terrestrial system utilizes high frequency single side band radio (HF/SSB). Data and text messages of short to moderate length will be handled by the ship's radio officer. This method of messaging is preferable as there are no direct charges involved. Again, this method can only be used for official traffic; other means are available for personal communications. Inmarsat and ATS are the satellite systems onboard. These are the preferred means for sending or receiving lengthy text or data files. See Satellite Communications for more information.

DEPTH RECORDING - The navigation outfit includes two fathometers; an International Offshore digital and a Furuno FE-600A recording fathometer. The displays for these units are located on the bridge and are used primarily for inshore navigation, harbor transits, etc. The ship's Doppler speed log (described elsewhere) also provides a depth reading down to about 200 meters. Deep sea soundings are accomplished with the precision depth recorder (PDR) controlled from the main lab and discussed in the scientific section of this handbook.

DIRECTION FINDING EQUIPMENT - Two radio direction finders (RDF) are employed aboard Melville. A Mackay type 4004-A medium frequency RDF installed in the chart room is for navigational purposes only. Of more interest to scientific users is the Simrad Taiyo TD-L1620 VHF direction finder located on the bridge. This RDF operates in the 110-170 MHz range, has a 30 channel memory and can scan up to 10 frequencies continuously. The Simrad is primarily for locating autonomous vehicles at sea. Transmitters for use with this system are provided by the scientific group or arrangements for the appropriate equipment can be made with the Resident Technicians Group.

FACSIMILE EQUIPMENT - Melville carries two facsimile machines. A Furuno FAX- 214 is located in the chart room and is dedicated to the receipt of weather maps and navigational warnings. The machine has a built in HF receiver and can be manually operated or programmed for automatic receipt of scheduled transmissions from shore stations. A Harris/3M 2110 fax machine is located in the radio room and is interfaced with the Inmarsat system. The Harris is configured for automatic reception of faxes from other stations. It can also be used to send faxes from the ship to any other fax machine. There are charges associated with use of the Harris as Inmarsat is a commercial system.

GYRO COMPASS - Melville carries two gyro compasses; a Sperry Mark 23 and a Sperry Mark 37. Under normal operating conditions both units are running with one unit on-line and the other in a standby mode. Output from the on-line compass is routed throughout the ship. In addition to compass repeaters, a number of electronic devices, including navigation systems and the shipboard computer system, have inputs from the gyro compass.

HAND-HELD RADIOS - The ship normally carries two portable Standard Horizon model HX200S marine radios. They are carried for internal communications and small boat operations.

HF/SSB COMMUNICATIONS - Communication is available via single sideband 2 to 30 MHz band width in both voice and teletype. At sea, official outgoing messages must be approved by both the chief scientist and the captain before the radio officer transmits them. The bridge maintains a watch on 2182 kHz--an international calling and distress frequency.

INTERNAL COMMUNICATIONS - Four installed systems facilitate internal communications around the ship. Some spaces are served by several systems while other spaces are served by only one. It is beneficial to note the differences in function, capability and operation of the various systems.

The two most heavily used systems are the sound powered phone and the Navy style intercom. The sound powered phone is very desirable aboard ship as it continues to function under all operating conditions and can be relied on during times of power outage. To use the system one simply selects the station he or she wishes to call and cranks the handle two or three times. In using the handset one must remember to depress the button in the handle both to talk and to listen. Similarly, with the intercom, one selects the desired station and depresses the lever to talk. The difference is in letting go the lever to listen. Once communication is established with another station, the intercom can be placed in a "hands free" mode which allows two way communications without pressing the lever to talk. This mode is not always effective as ambient noise levels in a space may prevent switching of the mics.

A number of spaces are equipped with ordinary telephones which can be used to call other spaces within the ship or to call out from the ship. See the section on satellite communications for more details on calling out.

A public address system operated from the bridge serves the weather decks fore and aft.

NAVIGATION EQUIPMENT - On the open ocean and during scientific operations Melville navigates primarily by Global Positioning System (GPS). A Trimble 10X receiver located in the chart room is used by the mate on watch for normal underway navigation and station operations. A Trimble 4000-AX 10 channel receiver is located in the computer room and is operated by the ship's computer technician. Both receivers are linked to the computer system which has terminals in key locations throughout the ship. GPS data is also fed to the dynamic positioning system (DPS) for precise station keeping and track line operations. Actual control of the ship for maneuvering can be accomplished with manual controls, by auto pilot or by the Kongsberg K-POS DP-11 DPS which allows joystick and "hands off" operation. A range of other navigation aids and tools provides for backup capability and alternative means of position fixing (as may be necessary in particular situations). Other forms of radio navigation include a transit satellite receiver, LORAN-C receivers radio direction finders, radars and a navtex receiver. Other electronic devices for navigation include a Doppler speed log and two fathometers. The complement of more traditional navigation tools includes anemometers, magnetic compass, sextants, chronometers, azimuth circles, telescopic alidade, binoculars, a range of navigational publications and charts and search lights. Some specific items are described in greater detail elsewhere in this section.

RADAR - Two Furuno marine radars are carried; an S band (10 cm) and an X band (3 cm). Radar consoles on the bridge have large viewing area, daylight displays and International Maritime Satellite, or Inmarsat, is the primary satellite communications system on board. Coverage is nearly worldwide. The system, as installed on Melville, can be used for voice, data and facsimile communications and the quality is generally excellent. It is important to note that Inmarsat is a commercial system; in most cases individual users are responsible for charges incurred through use of the system.

Through a linkage with the shipboard computer network, it is possible to send and receive Email via Inmarsat. Messages are exchanged once or twice daily with Scripps's campus computer in La Jolla; generally during off-peak hours when rates are lower. This is the preferred method for sending lengthy data or text files. Upon supplying billing information, the ship's computer technician will provide individuals with a personal account on the ship's computer system. Users will be recharged at a later date in proportion to the volume of data they transferred via Inmarsat. Users must realize that they will be charged for incoming traffic addressed to them as well as for outgoing traffic they generate onboard.

The ship's telephone system is also linked to the Inmarsat system. From any telephone on the ship one can direct dial any other telephone in the world. This can get expensive and is only possible with a personal access number. Users who anticipate lengthy and/or numerous calls can make arrangements for an access number with the captain or radio officer; billing information will be required. For short or infrequent calls it is better to pay cash to the radio officer upon completion of the call. For credit card holders there is a public telephone located in the scientific chart room on the 02 deck.

A standard office fax machine is linked to the Inmarsat system as well; access to and use of the machine is similar to that which governs the use of the telephones.

Inmarsat charges range from 6-10 dollars per minute depending on the time of day the system is used. There is a three minute minimum on voice communications. Faxes go over a voice grade circuit. Data transfers are the most economical as there are no time minimums and large amounts of data can be sent in a short period of time.

SEARCH LIGHTS - Three installed search lights facilitate certain operations at night. Two standard marine search lights are manually operated from the bridge; one on each wing. The third is a 2.5 kW xenon search light operated by remote joystick on the bridge. The light has a very powerful, high intensity, focusing beam and is ideal for locating autonomous instruments and other objects on dark nights.

SPEED LOG - Melville is equipped with an EDO Doppler sonar speed log. The main display and controls are located on the bridge. A remote display showing fore and aft and lateral velocities is located in the main lab. Outputs from the speed log are fed to various navigation devices as well as the shipboard computer system.

VHF COMMUNICATIONS - Two marine VHF (Very High Frequency) radios are installed in the log table on the bridge. These radios have all the frequencies/ channels authorized for such radios and have memory and scan functions. VHF is used for line-of-sight communications, however, under certain atmospheric conditions ranges can be considerably extended beyond the horizon. These radios are primarily used for ship to ship communications and to monitor distress and calling frequencies. Contact with shore stations is also possible when in range and personal calls can be made through a marine operator.