Installation and commissioning of VSAT equipment as part of the Gazpromneft Nord-West project.
The customer set the task of installing the VSAT KNS Z12 system on the tanker-bunker vessel type Gazpromneft Nord-West, with tuning and commissioning. The customer selected the VSAT KNS Z12mk2 antenna system itself, as well as the telecom operator, tariff and connection conditions.
installation of vsat system The installation of a small satellite ground station VSAT on a ship is carried out in the following sequence:
coordination with the customer of the installation site;
preparation of the project and its coordination with RMRS on installation;
manufacturing power fasteners;
installation of the antenna system itself;
installation under deck equipment;
setting up and starting the VSAT system directly in operation;
system performance test, conducting mooring and sea trials.
VSAT antenna system from the well-known Korean brand KNS, Z12 MKII has a 120-cm diameter mirror, transmits reception / emission in the Ku-band, and has Linear Cross-pol polarization. In addition to the antenna, an 8 W power transmitter (BUC) was installed. The minimum equivalent isotropically radiated power for the VSAT KNS Z12mk2 system is at least 38 dBW. At the same time, the overall dimensions of the system are quite large, weight 142 kg, and a dome diameter of about 140 cm.
Since KNS Z12 has a rather large mirror diameter, the signal reception quality in the northern and southern latitudes is very good. The system is equipped with gyrostabilization to constantly maintain the direction of the antenna to the satellite, compensating for the movement of the vessel and pitching. A separate spring-type vibration damping system is also provided. KNS Z12 has a wide range of operating temperatures – from – 20 degrees Celsius to + 55, which is important for ships making regular voyages from north to south and vice versa, and for one passage moving through regions with markedly different climatic conditions.
When installing the system, the main parameter becomes its mass-dimensional characteristics. These data determine the installation site of the antenna station, the conditions for its installation and the design of the power fixture, as well as the need to remove any objects from the antenna that could induce radio shadow. The mounting location was chosen on a raised platform, freestanding, with good stiffening ribs and convenient access directly to the receiver-emitter. Experts have proposed as an optimal option the installation of the system at the extension, provided that the additional power support with the platform is dismantled. In this case, the antenna was fixed with a technological hole to the rails of the superstructure to facilitate penetration under the protective cap. The need for access to shipboard cable routes and the absence of other protruding elements were taken into account.
For the installation of the underdeck elements of a small satellite earth station, one of the barriers was defined where there was already a 19-inch rack and convenient access to the control unit and other elements. The recommended climatic conditions for this type of equipment were kept in this room and there was a regulated crew admission regime. As a result, a power supply unit for the system and a cable route for the output of the network infrastructure were installed in this room.
The installation design was developed taking into account the requirements of RMRS for this type of equipment. The project was approved by the branch of RMRS and was accepted for work. No special comments were received from the inspector who coordinated the project. The project reflected both the internal part of the VSAT installation and the external one: their placement, connection, network infrastructure and power supply, as well as the direct location of all modules, the load on the deck, wind load and protection from external influences were taken into account. During the design process, the methodology for conducting all the VSAT system performance tests directly on board the vessel was regulated.
Since when choosing the location of the VSAT, an additional power support was needed, the original site had to be combined with a longer section of the support, thereby combining both elements of the power fastener. Steps were welded on the upper element for access to the technological hatch, and protection for cables in the form of a bent pipe. Welding was carried out ashore in a specialized workshop, painting in the color of the vessel was also carried out there. With the permission of the captain, the power fasteners were welded directly to the deck and deckhouse, thereby creating a direct base for mounting the VSAT KNS Z12 antenna system. The location of the power element of the fastener was consistent with the project agreed with RMRS.
To install an antenna system weighing 140 kg, a crane was required. The extension of the crane jib was enough to cover the distance between the pier and the direct installation site of the antenna. In order not to damage the external VSAT casing, ropes with canvas gaskets were used during installation. Also, after coordination of organizational issues, the system was directly mounted on a support.