Maintenance Handbook

SBS-800 Series Operator & Planned Maintenance Handbook
Chapter 2: Health and Safety Warnings
KH-1601-2 Issue 6
Page 7 of 80
WORKING ALOFT
CAUTION: SAFETY ALOFT
When working aloft or near any radar scanners, moving or RF radiating equipment, ALL power sources to the platform and
equipment including Anti-Condensation Heater (ACH) supplies must be fully isolated.
Prior to working aloft, all AC supply breakers to the system must be switched OFF and locked. Ensure someone in authority or
at ground level knows of your intentions and ensure that suitable clear warnings are in place.
Ensure all means of access aloft are secure and beware of wet or slippery ladder rungs and working areas.
All working at height health and safety requirements and procedures, including the inspection and use of personal protective
equipment (PPE) such as approved safety harnesses and gloves, must be adhered to at all times as required by your
employer, site regulations, shipyard and/or vessel.
CAUTION: SAFETY CORDON
When working aloft, a safety cordon must be established and managed below the working area(s).
CAUTION: DROP HAZARDS
When working aloft, all tools, Line Replacement Units (LRUs) and any loose items must be safely stowed or secured so that
they cannot present a drop hazard.
CAUTION: WEATHER CONDITIONS
When weather conditions are poor, a full risk assessment must be carried prior to working aloft as defined by an individual’s
employer or shipbourne safety procedures.
Poor weather conditions can include but are not restricted to high winds, heavy rain, snow, ice or if access is required at sea,
risk of vessel pitch and roll.
MAN ALOFT SWITCH/ANTENNA ISOLATION.
Antenna rotation and transmission can be inhibited via a Man Aloft Switch (MAS) or an ‘Antenna OFF/Free’ keyswitch. These
mechanisms can be used by a person who sees a potential hazard such as a loose halyard and decides to protect the antenna.
When activated, the reason for loss of turning is detected by the system and is reported to the local and remote users.
SAFETY SWITCHES
Antenna
Rotation
keyswitch
The Antenna Rotation keyswitch is located on the door of the internally mounted Radar Distribution
Unit (RDU)
The key for the RDU keyswitch is captive when set to Free (enable rotation) but can be removed when
the keyswitch is to OFF.
When in the OFF position all AC power to the antenna and transceiver is isolated thus stopping
antenna rotation and transmission.
The key should be removed and retained by the person who intends to enter the potentially hazardous
volume of the rotating antenna.
Man aloft switch
(MAS)
The man aloft switch (MAS) is designed to be installed such that it is still viewable for the person who
is carrying out maintenance tasks.
When set to the ‘OFF’ position the transceiver/gearbox is isolated from all AC power thus stopping the
antenna rotation and transmission.
The Man Aloft switch, Motor ON/OFF and Antenna Rotation keyswitch form part of a safety current loop. This safety loop is purely
hardware (no software), when the current loop is opened, AC mains supplies to the transceivers and antenna inverter are switch
OFF by use of contactors.
Kelvin Hughes recommends that the key switches noted above are used in conjunction with the man aloft switch but also
recommend that radar users carry out a safety assessment and risk mitigation procedure in terms of interlocks prior to approving
any work on the equipment.
Full details on isolating the systems from the AC supplies can be found in Section 4.5 of this handbook.