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.

KB-30A electronic horn/hailer system

Kahlenberg marine electronic horn/hailer systemThe Kahlenberg KB-30A provides a useful option where a fully electronic solution to sound signalling and hailing is preferred. The sound pressure level of this 100W hailer is 131dB (1/3 octave band) and it is suitable for use on vessels up to 75m (246ft) in length.

The horn is waterproof to IP67 and constructed of durable materials, with aluminium alloy for the horn and driver and powder coated steel for the bracket. A heater is included to eliminate moisture and to provide additional protection from freezing. Operating temperature range is +200°C to -50°C.

Kahlenberg's attractive console mount M511D control unit has a remote console mount microphone jack included; auxiliary audio inputs are also possible.

The fundamental frequency of the Kahlenberg KB-30 electronic horn/hailer system when used in sound signal mode is 695Hz; the control unit sounds the appropriate signal for the following restricted visibility requirements under Rule 35 of the COLREGs:

  • Vessel underway (Rule 35a)
  • Vessel underway but stopped (Rule 35b)
  • Vessel restricted in ability to manoeuvre (Rule 35c)
  • Vessel being towed (Rule 35d)
  • Vessel at anchor (Rule 35f)

The Kahlenberg M-511D control unit also handles the following

  • Manoeuvring codes: altering course to starboard, port, astern, danger
  • Start/stop automatic function
  • General alarm function in line with IMO/SOLAS requirements with accidental touch protection
  • Integrated 'at-will' switch

The whole system runs on 24V DC.

Listen to the Kahlenberg KB-30 electronic horn/hailer system

Kahlenberg KB-30 electronic horn/hailer system downloads

Kahlenberg KB-30 electronic horn/hailer system brochure
Kahlenberg KB-30 electronic horn/hailer system technical drawings


Further information

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