About Kahlenberg UK

Kahlenberg UK Ltd is the European distributor for Kahlenberg Industries, Inc. providing full European support and local stock for Kahlenberg marine and industrial air horns, sound signals, controllers, air compressors and the company's other products.

Please contact us for further assistance at or on +44 (0)1635 35353

Sound signal legal requirements

IMO COLREGs bookWhile countries across Europe will have local laws that apply to ship and boat navigation, there is a common requirement worldwide for all leisure, commercial and military vessels to conform to the IMO International Regulations for Preventing Collisions at Sea. As Steve Austin, Senior Policy Lead at the UK Maritime & Coastguard Agency (MCA) explains: "The COLREGs apply to all vessels, there is no differentiation between coded and non-coded vessels. Should the whistles prove not to conform then they will need to be modified or changed."

"Whistles should conform to the performance in COLREGs, Appendix III and the appropriate parts of IEC 60945 to EN60945 which deal with the marine operating environment."

All Kahlenberg products meet or exceed these requirements. Many other new and currently installed sound signals are non-compliant and might be breaching maritime law and invalidating insurance cover.

S-330-DVM H marine air horn

Kahlenberg S-330 marine air horn

The Kahlenberg S-330-DVM-H marine air horn provides a fully IMO compliant and ABS certified sound signal for commercial vessels up to 75m (246ft) with a heater for extreme conditions, all in a very compact package with the same benefits of the purpose-designed S-330.

The S-330-DVM-H features a heated operating valve offering dual electric operation with a manual override to provide for redundancy, enhancing crew and vessel safety.

The S-300-DVM-H’s heater is watertight and thermostatically controlled. It operates on 24VDC and 120VAC or 230VAC.

The finish of the horn is TGIC sky white powdercoat and it can safely operate down to -4°C. The S-300-DVM can be mounted to vertical or horizontal surfaces.


The S-330-DVM-H is an extremely attractive proposition for vessels where weight and space saving is a consideration or where a compact IMO compliant back-up whistle to the vessel’s main sound signal is required.

As with all Kahlenberg sound signals the S-330 is built in quality materials - spun brass and cast bronze, with a special alloy diaphragm. Its seamless bell avoids corrosion trap issues.

Because of the choice of design and materials you can expect extremely long and reliable service.

The fundamental frequency of the Kahlenberg S-330-DVM-H marine air horn is 330Hz and its SPL dB(A) is 136dB. Air consumption is 9CFM (4.2 l/s) @ 100psi (7 bar). It works on a wide range of pressures from 50-200psi (3.5-14 bar). It measures 18.7in (475mm) long with a 6.5in (164mm) bell.


Kahlenberg S-330-DVM-H marine air horn brochure

Kahlenberg S-330-DVM-H marine air horn technical drawing


Further information

Call Kahlenberg UK now on +44 (0)1635 35353 or email