Bow thruster installation

[Vronsky]

Was visiting BOOT in Dusseldorf this weekend, and noticed how bow thrusters in mass production motor boats are installed these days, here's an example >>

Bow thruster on the stern of a motor boat - ship mooring thrusters - Koop deze stockfoto en ontdek vergelijkbare foto's op Adobe Stock https://stock.adobe.com/nl/images/bow-thruster-on-the-stern-of-a-motor-boat-ship-mooring-thrusters/257173748

Please note those 'seams' below the opening, as if the pipe has been sort of 'cut' into the hull...
The construction doesn't seem to be the usual pipe that's inserted into the hull.

Does anyone know more about this construction ??

THANKS,
V.

 

[Ad Hoc]

No images in the link?

 

[BlueBell]

I saw images both times I opened the link.

 

[Ad Hoc]

This is all I see:

 

[bajansailor]

I can see the photos here - but everything is written in Dutch, whereas Ad Hoc's appears to be in English?

<mod note: removed now that Ad Hoc has seen them; appreciate the desire to help, but attaching Stock photos themselves to a forum post here would seem to violate Adobe's copyright on the stock photos.>

 

[Ad Hoc]

Ahh....thanks Bajansailor

The recess, or cut into the hull as you cite, is down to the shape of the hull and not wanting to disturb the flow of water past the orifice. Since at speed an orifice like this will or could or can create turbulence/eddies. It can be noisy as well as loss of speed and erosion issues.
So it is recessed slightly and the shape leading to and/or from the orifice is tapered to the hull shape to prevent the aforementioned.

 

[bajansailor]

Ooops - apologies to the Moderator for doing that, I certainly didn't think for a moment that there would be any conflict as a result of me posting these photos.
But I can see your reasoning - folk do get very uppity about copyrights (and possible litigation) nowadays.

 

[Ad Hoc]

Ooops - - folk do get very uppity about copyrights (and possible litigation) nowadays.

Im not sure?
I have Adobe professional, so I don't know why I couldn't view them. If they are "locked" for some copyright/privacy issue, then why post them on a public forum?
Doesn't make sense either way really....
What you did was perfectly fine as far as I could see.

 

[Boat Design Net Moderator]

I don't think it's related to why they weren't viewable for you on the stock.adobe.com website -- the image appeared fine for me on the link above, so maybe something relating to location or a temporary issue with a CDN that site is using serving your region maybe.

However, I want to be careful not to violate Adobe's Terms of Service which I don't think would allow their stock photos to be attached to a forum post here unless a specific license was purchased for each stock photo in question.

 

[Ad Hoc]

I don't think it's related to why they weren't viewable for you on the stock.adobe.com website -- the image appeared fine for me on the link above, so maybe something relating to location or ...

My bad. My phishing/spam/ad blocker...ive just noticed it blocking the links.
Once i allowed the link to view fully.... i see all the images now.
Doh!

 

[Vronsky]

Ahh....thanks Bajansailor

The recess, or cut into the hull as you cite, is down to the shape of the hull and not wanting to disturb the flow of water past the orifice. Since at speed an orifice like this will or could or can create turbulence/eddies. It can be noisy as well as loss of speed and erosion issues.
So it is recessed slightly and the shape leading to and/or from the orifice is tapered to the hull shape to prevent the aforementioned.

The fairing behind the orifice serves to reduce turbulence > hard to believe those vertical 'seams' are meant to do the same.
Still think there's some reason in the manufacturing process behind it.