LowNoise Tunnel Thrusters

Brunvoll LowNoise Tunnel Thrusters are resiliently mounted, full-length double-tunnel thrusters designed to cut noise in adjacent cabins. Typical cabin noise next to conventional tunnel thrusters is 75-88 dB(A); the LowNoise design reduces this by 11-15 dB(A), and reductions of 20-25 dB(A) have been verified when combined with other measures.

Key features

• Noise reduction of 11-15 dB(A)
• Resiliently mounted, full-length double tunnel
• Delivered complete from factory with no assembly at the yard
• Tunnel length and shape tailored to the hull lines; no additional welding of tunnel extensions
• Inner tunnel delivered with conical inlets; grids pre-installed on request
• Cathodic protection and paint treatment including anti-fouling
• CP propeller with skew blades; one-way rotation for optimal gear loading
• Proven lifetime of more than 25 years, with easy access to vital parts

Technical data

| Model | Propeller diameter (mm) | Power range (kW) |

|---|---|---|

| FU 37 | 1,000 | 100-250 |

| FU 45 | 1,375 | 200-450 |

| FU 63 | 1,750 | 400-900 |

| FU 74 | 2,000 | 800-1,400 |

| FU 80 | 2,250 | 1,000-1,500 |

| FU 93 | 2,500 | 1,500-2,200 |

| FU 100 | 2,750 | 1,800-2,300 |

Other sizes are available on request. Motor starting options: direct on-line (DOL), star-delta, auto-transformer, electronic soft starter or frequency converter (6-pulse, 12/24-pulse or active front end); the motor is started with the propeller in zero pitch.

Engineering services

• Selection of thruster type, size and location
• Structural thruster-hull integration
• Noise assessments

Applications

Cruise ships, megayachts, diving support vessels and other offshore service and research vessels where noise reduction is critical.