Installation & Service manual
VSS system
A100K10874
2
2. General Description
The VSS system enable the navigator on a one
man operated bridge to listen to the environmental
sound signals from other ships or fog horns that
are audible outside the ship when standing inside
the enclosed bridge space.
The system is monitoring, according to rules;
Resolution MSC.86(70), frequencies between
70 and 820 Hz.
Four (4) VSS-222 weatherproof microphones are
mounted outside the wheelhouse and connected to
the VSS-111 audio amplifier and loudspeaker
within the bridge.
The VSS system has «remote muting» of the
amplifier circuit when the vessel’s own tyfon is
activated.
The VSS system has squelch function. Adjustable
muting of undesirable sound sources.
Microphone Direction Detector (MDD)
By use of four microphones the MDD will detect
the direction of the incoming signal and activate the
corresponding LEDs at the VSS-111 front panel
The four microphones operate in pair depending of
the direction of the received sound signal.
The microphone first detecting the sound will be
registrated in MDD and it will lock against
influence from the other microphone.
This will repeat each time a signal is strong enough
to trig the detector.
The «bridgewing» pair of microphone will indicate
if the sound is coming from the Sb or Ps direction,
while the other pair tell if the sound signal is coming from «Fore» or «Aft».
The combination of above will indicate the actual sector (see illustration above)
The VSS «Sound Signal Reception System» has been EMC tested according to relevant CENELEC and IEC
standards and type tested in order to qualify for Type Approval by Det Norske Veritas / Bureau Veritas / RINA
Det Norske Veritas (DNV), Certification Notes no. 2.4.; «Environment test specification for Instrumentation
and Automation Equipment» Optional EMC requirements:
Det Norske Veritas (DNV) Supplementary EMC and Environmental Testing.
Technical Report No.2003-3124 Revision No.01
IEC 60945, Fourth edition, 2002-08
EN50081-1 / EN50082-2 (CENELEC, Harmonized standards)
4 x VSS-222
ON
OFF
VOLUME
DIMMER
SQUELCH
