Sea Tel 6012-12w Installation Manual Download

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Site Survey

6012-12W Installation Manual

the girder columns provides ample support to the antenna pedestal and locates the antenna
weight where it will influence the natural frequency of the mast the least.

2.5.4.

Truss Mast

Truss masts are a variant on the girder mast concept. Rather than a pair of columns supporting a
girder beam, the construction is a framework of

tubular members supporting a platform on which
the antennae and other equipment are mounted. A
typical truss mast is shown in this photograph.

Like a girder mast, truss masts are especially stiff in
the athwart ship direction. Unlike a girder mast, the
truss can be made to be nearly as stiff in the
longitudinal direction. Truss masts are particularly
difficult to estimate the natural frequency – since a
correct modeling includes both the truss structure
of the supports and the plate/diaphragm structure
of the platform. In general, the following guidelines
apply when determining the adequate support for
mounting an antenna on a truss mast:

Antenna ADE pedestal gussets should align with platform stiffeners which are at least 200
millimeters in depth and 10 millimeters in thickness.

When possible, the antenna ADE pedestal column should align with a vertical truss support.

For every 100 kilograms of ADE weight over 250 kilograms, the depth of the platform
stiffeners should be increased by 50 millimeters and thickness by 2 millimeters.

Sea Tel does not have a recommended arrangement for a truss mast – the variability of truss mast
designs means that each installation needs to be evaluated separately.

2.6.

Safe Access to the ADE

Safe access to the ADE should be provided. Provisions of the ship’s Safety Management System with regard
to men aloft should be reviewed and agreed with all personnel prior to the installation. Installations greater
than 3 meters above the deck (or where the access starts at a deck less than 1 meter in width) without cages
around the access ladder shall be provided with means to latch a safety harness to a fixed horizontal bar or
ring.

The access hatch for the ADE shall be oriented aft, or inboard, when practical. In any case, the orientation of
the ADE access hatch shall comply with the SMS guidelines onboard the ship. Nets and other safety rigging
under the ADE during servicing should be rigged to catch falling tools, components or fasteners.

2.7.

Below Decks Equipment Location

The Antenna Control Unit, Terminal Mounting Strip and Base Modem Panel are all standard 19” rack
mount, therefore, preferred installation of these items is in such a rack. The ACU mounts from the front of
the rack. The Terminal Mounting Strip and Base Modem Panel mount on the rear of the rack.

The Satellite Modem, router, VIOP adapter(s), telephone equipment, fax machine, computers and any
other associated equipment should be properly mounted for shipboard use.

Plans to allow access to the rear of the ACU should be considered.

2.8.

Cables

During the site survey, walk the path where the cables will be installed. Pay particular attention to how cables
will be installed; such as what obstacles they will be routed around, difficulties that will be encountered and
the overall length of the cables. The ADE should be installed using good electrical practice. Sea Tel
recommends referring to IEC 60092-352 for specific guidance in choosing cables and installing cables onboard
a ship. Within these guidelines, Sea Tel will provide some very general information regarding the electrical
installation.

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EAR Controlled - ECCN EAR99