Tokyo Siren SH-180 Marine Fog Horn

Tokyo Siren Fog Horn Siren Type SH-180

The Tokyo Siren Type SH-180 is a hand-operated mechanical marine sound signaling appliance designed specifically for emergency audible signaling, distress communication, and restricted-visibility navigation. Originally engineered by Tokyo Siren Co., Ltd. (Tokyo, Japan), the SH-180 operates independently of shipboard mains, battery banks, or compressed-air lines.

The SH-180 utilizes an internal high-torque step-up geartrain coupled to a multi-port centrifugal air rotor and stator assembly. When actuated via the fold-out manual hand crank, the centrifugal rotor draws ambient air axially and expels it across precision stator ports, producing a concentrated, omnidirectional acoustic output capable of penetrating dense marine fogbanks up to 1.5 nautical miles (approx. 2.8 km) under standard atmospheric conditions.

Model Details

• Manufacturer: Tokyo Siren Co., Ltd. (Tokyo, Japan)
• Equipment Type: Portable Hand-Operated Marine Fog Horn / Rotary Emergency Siren
• Model Designation: Type SH-180
• Manufacturer Part Number (MPN): SH-180-M
• NATO Stock / Marine Stores Guide Equivalent: IMPA 33 04 41 / ISSA 47.004.01 (Sound Signal Appliances / Emergency Fog Horns)

Technical Details

Features

1. Zero-Energy Dependent Operation: Fully mechanical hand-crank drivetrain requires no shipboard AC/DC electrical supply or auxiliary compressed air, ensuring 100% operational readiness during dead-ship conditions, emergency blackouts, or main engine room flooding.
2. Acoustic Sound Projection: Delivers an acoustic sound pressure level exceeding 120 dB(A) at 1 meter, achieving an effective COLREGs auditory navigation range of 1.5 nautical miles across low-to-mid frequency octaves (approx. 350 Hz to 450 Hz).
3. High-Torque Internal Gearbox: Precision bronze and hardened carbon-steel gear mechanism provides optimal gear reduction, enabling full acoustic resonance at an operator input cadence of just 33 to 35 handle revolutions per minute (RPM).
4. Corrosion-Proof Marine Casting: Constructed with marine-grade cast aluminum rotor/stator housings, stainless-steel assembly hardware, and brass horn bell flare treated with anti-corrosive industrial marine coating.
5. Integrated Self-Contained Deployment Chest: Housed in a brass-hinged marine hardwood chest equipped with perimeter gaskets, fold-out stabilizing footings, and quick-release bridge wing stanchion mounting clamps.

Applications

• SOLAS Secondary / Emergency Whistle: Auxiliary signaling appliance for commercial cargo vessels, oil/chemical tankers, bulk carriers, and container ships under IMO SOLAS Chapter V Regulation 35 during power blackouts.
• Tug, Barge & Coastal Towing Signaling: Maneuvering and fog warning sound signals for non-propelled barges, coastal pushed vessels, and inland towing convoys where onboard power generation is restricted or intermittent.
• Workboats, Offshore Supply & Salvage Craft: Primary or standby emergency audio alert signal for offshore support vessels (OSV), crew transfer vessels (CTV), and specialized marine salvage operations.
• Shipyard Drydock & Dead-Ship Towing Operations: Mandatory audible maneuvering signaling during unpowered vessel transfers, dead-ship transit to decommissioning yards, and basin berthing maneuvers.
• Lifeboat, Survival Craft & Rescue Station Equipment: High-output manual signaling gear deployed on tender stations, shore bases, harbor master emergency points, and survival operations.

Compatibility

• Vessel Length Classes:
  • Vessels under 20 meters in length: Serves as a standalone primary manual sound signaling appliance under COLREGs Rule 33(b).
  • Vessels 20 meters to 75 meters: Serves as an auxiliary secondary signaling device when primary pneumatically operated horns fail.
  • Vessels over 75 meters / Unlimited Tonnage: Emergency backup whistle signaling on the bridge wings in accordance with vessel safety equipment cert requirements (Form E / Form SEC).
• Mounting Integration: Compatible with standard 1.5″ to 2.0″ bridge wing stanchions, monkey island guard rails, or flat bulkhead brackets via the unit’s clamp assembly.

Frequently Asked Questions

What is the audible range of the Tokyo Siren SH-180 in bad weather?

The Tokyo Siren SH-180 has an acoustic range of approximately 1.5 nautical miles under calm conditions with wind under 4 knots. In heavy head-winds or stormy precipitation, audible range decreases to roughly 0.5 to 0.75 nautical miles, which still exceeds the minimum emergency auditory distance mandated for auxiliary manual sound signals under international regulations.

Does the Tokyo Siren Type SH-180 require any electrical hookup or air line?

No. The SH-180 is a completely mechanical, self-contained hand-cranked rotary siren. It does not use electrical wiring, terminals, solenoids, batteries, or compressed air connections. It is engineered specifically for dead-ship maneuvers and catastrophic bridge blackout emergencies.

Can the Tokyo Siren SH-180 pass a SOLAS safety equipment audit during annual surveys?

Yes. Maritime safety inspectors (flag state inspectors and classification society surveyors) approve the SH-180 as a compliant secondary emergency sound signaling appliance under COLREGs Annex III and SOLAS Chapter V, provided the gear mechanisms spin freely, the mounting latches operate, and certified acoustic output exceeds regulatory minimums.

How do you regulate sound patterns (blasts) on a manual rotary horn?

COLREGs Rule 35 mandates specific long and short sound blasts (e.g., one prolonged blast every two minutes for power-driven vessels making way through fog). On the SH-180, a prolonged blast (4 to 6 seconds) is generated by maintaining 33 RPM for that exact duration, followed by resting the handle to allow the centrifugal airflow to cease instantly.

Is the unit safe for hazardous environments such as oil and chemical tankers?

Yes. Because it uses no electrical circuits and generates no spark-inducing electrical discharge, the mechanical siren is inherently non-sparking in relation to explosive vapors, making it safe for use on the weather decks and open bridge wings of LPG, LNG, and chemical product carriers.