Designing The Antenna Mast - Furuno FELCOM 50 Installation Manual

1.2

Designing the Antenna Mast

General
To facilitate servicing, construct a mast of 1000 mm in height. (See page 5.) The paragraphs
which follow provide guidelines for selection and construction of the mast.
Guardrail, platform
Fit the mast with a guardrail and platform (or steps), for serviceman's safety. (In most
installations the serviceman stands on the platform while checking the radome. Thus this
distance should be secured for ease of servicing.) The guardrail should be as high as
possible for sufficient safety.
Mast strength
The mast material must be sufficiently strong to meet the
demands of the marine environment. It should satisfy the
following requirements.
• It must be able to support radome mass plus at least 2.5
cm of ice and snow. Special consideration should be given
if the unit is operated in areas of heavy snow or freezing
temperature.
• Mast bending moment must be able to withstand expected
maximum pitching, rolling and wind pressure.
• To prevent resonance at low frequencies (about 5 Hz),
four stays can be fixed between the mast and the
mounting base.
Antenna unit mass
Platform, guardrail mass
Expected ice and snow
Maximum wind pressure (at wind speed 75 m/s)
Item
4
Wind
Pressure
Mass
Mast
15 kg ± 10%
3777.5 N
Bending
Moment
Mass