Gulfstar MII Noise Level

[kpinnn]

One of our reasons for a shift from an express cruiser to a trawler is comfort level. I mean comfort while making headway. Reciently I looked at a MkII and started the two 62 HO diesels to check noise level. I foud it to be quite high 95 decibals while in neutral at 2000 RPM's and sitting in a slip. I am wondering if this is expected. Some of the conditions that might make a difference is 1st the boat was in a covered slip, second there was not a load on the engines. I also know that probably the cruise is about 1800 RPM's The 95 is actually higher than our express cruiser at 3000 rpn's and on plane. Or I should say close to the same level. Any comments? Is that an expected level? Do you think the conditions I mentioned can make a difference. I did not see any insulation on the undersides of the hatches to the engine room.

Ken

 

[LaBomba]

Ken, I have about 2" of insulation on the underside of my hatches, have only one engine but I am nowhere near 95 db, I would guess 80 to 85 tops and at 1800RPM. The covered slip, I would think, could have some effect.

 

[Brooksie]

Check your sound insulation in the engine compartment not just the hatch covers. Go to Soundown and read the information. There is no reason, with the materials available, that you should not be able to carry on a conversation at normal voice level with either 1 or 2 engines. On the other hand, it doesn't take much to screw up a good soundproofing job; meaning that a small un-noticed opening or lask of a gasket, can negate a lot of properly installed soundproofing material.
On Island Seeker, about the same size w/ single diesel, all you can hear when underway on the bridge is the bow wave. In the cockpit, the water splashing out the exhaust from the waterlift. Inside, a quiet conversation can be held anywhere.

 

[Hardscrabble]

I have a free app that has a decibel meter - SkyPaw - pretty cool. Pretty close to as good as a calibrated "real" one I use. Close enough to help you track down the areas where the sound is escaping.

If you establish a baseline and chart it different points on the boat at different rpms, as you make improvements you can see what gives you the best bang for the buck. Insulation quality as well as placement is key.

Good luck

 

[BruceK]

kpinnn, was that with the ER access hatch open or closed? I hope the former.
It would be unusual not to have the ER roof and hatch insulated. On one boat I had, I renewed the insulation,filling all gaps, and it helped a lot.
A lot of insulation panels are self adhesive (at first anyway) and easy to fit, so if there is none now, it can be done fairly easily, won`t cost much (in boat terms) and will be rewarding.

 

[FF]

Time to spend some bucks,,,





Barrier Acoustic Insulation, Carpet Underlay - Soundown - Barrier ...

www.[B]soundown[/B].com/AI.htm‎
Soundown Barrier Composite Insulation is the most commonly used material due to its wide range of applications and excellent acoustic properties.

Soundown - peace and quiet for architectural, marine, & industrial ...

www.[B]soundown[/B].com/‎
FOR PEACE AND QUIET. Worldwide Leader in Noise and. Vibration Control Engineering. ARCHITECTURAL · MARINE · INDUSTRIAL. Contact: Soundown ...Google+ page · Be the first to review
16 Broadway Salem, MA 01970
(978) 745-7000

 

[Northern Spy]

Reading comprehension here folks. He doesn't own the boat he is looking and asks if loud is normal. No. It is not. As discussed most pilothouse boats require and have lots of sound insulation.

 

[Codger2]

.
On one boat I had, I renewed the insulation,filling all gaps, and it helped a lot.

I added a hatch for an easier access to my oil fill and coolant fill. At first blush, I didn't replace the sound insulation but after hearing the result, I added two sound deadening boxes to the underside of the hatch.