Defence Q&A Why surface ships do not have own noise detection system?

[zio]

What is the reason behind surface ship does not have own noise detection system but subs have?

 

[Tonyukuk]

What is the reason behind surface ship does not have own noise detection system but subs have?

Some surface vessels do have sonar.

 

[Anmdt]

• They don't have a limited space for own-noise suppression systems (see Prairie Masker) where they can be installed with noise suppression or masker systems.
• Surface ships prioritize performance over acoustic signature since a long time, own-noise is more of a concern for sonar efficiency in recent years.
• Surface ships can measure self noise on the go, where a team is disembarked with measurement devices on a RHIB, place hydrophones, collect data and process abnormalities, could even take place while the ship is moving.
• Surface ships also goes noise measurement tests when docked, after maintenance or MROs, also on the sea trials following the maintenance.
• Surface ships always runs on a diesel engine or gas turbine, even in DE mode, unlike submarines that may run on batteries and electric motors, only. Thus, minor changes on equipment noise is little to none in contribution to the whole noise.
• A submarine's whole concept relies on remaining undetected, acoustic signature is the most prominent and directly measured signature (EM, Magnetic, indirect IR, Wake detection is secondary and rather weak and hard to track-identify, whereas an Acoustic signature is literally a "signature"). However, for a surface ship acoustic signature is rather a concern of being detected-tracked by submarines while IR and visual signature is more prominent. Here, performance lies ahead being silent, unless it is an ASW ship or a Survey ship which operates Sonars etc.
• Surface ships has an acoustic database which in relavant conditions, reflects the ship's noise level. Little deviation occurs by the time, however since the engines are the dominant factors, these deviations are negiligible. Abnormalities are detected by internal and external acoustic inspections.

Prairie / Masker

INFORMATION SHEET

 

[Loban]

Surface ships don’t usually have their own noise detection systems because their engines and propulsion dominate the noise, so small variations from equipment aren’t significant. Submarines rely on stealth, so detecting and minimizing acoustic signatures is critical for them. Surface ships can still monitor noise using teams with hydrophones or during maintenance and sea trials, but for most ships, performance and speed take priority over acoustic stealth.