This MARCO PW3 pneumatic brass signal horn, model PW3-BC, is a compressed-air-operated maritime sound signal for vessels of 20-75 m. The horn features a chrome-plated surface, a 24 V electric solenoid valve, and a sound pressure level of 132 dB measured at 1 m as 1/3 octave.
The sound is produced using compressed air, while the 24 V DC electrical supply activates the solenoid valve. The horn operates at 6-12 bar and can be connected to the vessel's existing compressed air system or a separate suitable compressor. The specified air hose is 8/6 mm with an 8 mm outer and 6 mm inner diameter.
The horn is made of brass with a chrome-plated finish and has a horn bell of Ø300 mm. The product dimensions are H 260 × L 449 × W 300 mm. The delivery includes an electric solenoid valve, operating switch, and mounting accessories.
For installation, the horn must be positioned with an approximately 5° downward tilt so that water does not collect in the horn funnel. The horn housing is secured with M5 brackets through Ø5.5 mm mounting holes, while the solenoid valve is mounted on a flat surface with M4 screws. The installation also requires an Ø8 mm lead-through for the air hose and an Ø8 mm lead-through for the solenoid valve wiring.
For the electrical installation, a cable cross-section of 1.5 mm² is recommended for battery connections up to 20 m and 2.5 mm² for connections up to 40 m. The maximum power consumption is 2.5 A, and the horn's nominal frequency is 315 Hz.
The PW3-BC complies with COLREG 1972 and IMO Class III and holds approvals from RINA, Lloyd’s Register MCA, Bureau Veritas, BSH, and NMMA. The compatible MARCO M3 compressor in the 24 V version can be used as a separate compressed air supply and can be found under item no. 21.441.09 and manufacturer item no. 13510013.
Documented spare parts include 24 V solenoid valve R5200005, mounting accessories for the solenoid valve R5200024, diaphragm kit R5000040, and protective cap R5200006. If impurities or metal shavings block the diaphragm, the horn can be disassembled, the diaphragm cleaned, and the unit reassembled.
Key featuresPneumatic signal horn for vessels of 20-75 m
24 V DC electric solenoid valve
Sound pressure: 132 dB at 1 m
Frequency: 315 Hz
Working pressure: 6-12 bar
Chrome-plated brass construction
Horn bell: Ø300 mm
Product dimensions: H 260 × L 449 × W 300 mm
COLREG 1972 and IMO Class III
Solenoid valve, operating switch, and mounting accessories included
