MARCO PW3 pneumatic brass ship's horn for vessels 20–75 m is a white-painted, compressed air-driven signal horn with an electric solenoid valve. This 24 V variant delivers a sound pressure of 132 dB at a distance of 1 meter and is intended for vessels from 20 m to under 75 m.
The horn generates the sound signal using compressed air and can be connected to the vessel's existing compressed air system or a separate compressor. It requires a supply pressure of 6–12 bar. The electrical installation operates the solenoid valve and has a maximum power consumption of 2.5 A. The horn's current frequency is 315 Hz.
The white-painted brass horn has a bell diameter of Ø300 mm and total dimensions of 465 × 300 × 245 mm. An electric solenoid valve, operating switch, mounting accessories, and two threaded pipes of different lengths are included. The threaded pipes can be shortened if mounting conditions require a shorter attachment.
The compressed air connection is designed for an 8/6 mm Rilsan or nylon hose, corresponding to an 8 mm outer and 6 mm inner diameter. The horn is mounted with an approximately 5° downward inclination so that water can drain out of the horn bell. The solenoid valve is mounted on a flat surface with M4 screws. For 24 V installations, a 1.5 mm² cable is recommended for connection lengths up to 20 m, and 2.5 mm² for lengths up to 40 m.
The PW3 is type-approved according to COLREG 1972 and IMO Class III. Approvals include RINA, Lloyd’s Register MCA, Bureau Veritas, BSH, and NMMA as well as NMMA/ABYC A-23. RINA certificate ELE333323CS covers the PW3 for vessels in the 20–75 m class, a documented audibility of 1 nautical mile, and a compressed air supply of 0.60–1.20 MPa. The certificate is valid until October 29, 2028.
The operating temperature is from -25 to +60 °C, and the maximum relative humidity is 90 %. If impurities or metal shavings block the membranes, they can be disassembled, cleaned, and reassembled in the prescribed order.
Related accessories and spare parts
A dedicated 24 V M3 compressor with item no. 21.441.09 can be used as a compressed air supply. Documented spare parts include 24 V solenoid valve R5200005, horn without accessories R5200001, membrane R5000007, operating button R5000004, protective cap R5200006, mounting kit R5000022, and valve accessories R5200024.
Key featuresPneumatic ship's horn for vessels 20–75 m
24 V electric solenoid valve
Sound pressure: 132 dB at 1 m
Frequency: 315 Hz
Compressed air pressure: 6–12 bar
White-painted brass construction
Horn bell: Ø300 mm
Type-approved according to COLREG 1972 and IMO Class III
Electric valve, switch, and mounting accessories included
