Hey Kapitan, I wonder how these would scale up?

Kapitan · 02-04-22, 08:51 AM

Would love to see it but video unavailable

ET2SN · 02-04-22, 11:48 AM

Quote:

Originally Posted by Kapitan

Would love to see it but video unavailable

Watch On Youtube

"Over the course of two days, BoatTEST’s captains tested a pair of Sharrow Marine props and a pair of Yamaha Saltwater Series II props on a World Cat 325 DC".

Kapitan · 02-04-22, 01:14 PM

My initial thoughts on this would be it most certainly could be scaled up and also multi bladed (seen some pictures of a 5 blade)

Doing a quick bit of research it does seem the cavitation profile would be more concentrated, so the use of a diffuser may be a bonus with it.

A lot of warships today use variable pitch screws this would clearly be a benefit as you don't have to rotate the blade eliminating the gearing.

The main draw backs I can see:

Time to produce, these screws would be more time consuming than conventional ones, plus the casting process would have to be changed drastically too.

Critically would the screw be able to take the torque load of say a DDG ?

Damage to the screw would mean an entirely new screw rather than a blade switch out, this would require dry docking as opposed to in water blade changes. (rare but does happen)

looking at the website they do offer small commercial use of the screw but haven't gone beyond 10m vessels at this time (according to their website)

Overall though it would be a good idea to test this on say a auxiliary vessel then maybe see if it can take the torque of a DDG, the reason for the auxiliary is to see if they are better at saving fuel than azipods.
From what they are saying it does have benefits in the fuel economy range and it also eliminates gearing to reverse the shaft when going astern.

Just my thoughts after a quick read up and watching that video

mapuc · 02-04-22, 01:22 PM

I have scaled up a blueprint of a Mærsk supply vessel-I went to a special shop and got it scaled double up(the blueprint)

Did not build it-Sold the blueprint to some other guy on a modelforum.

Markus

ET2SN · 02-04-22, 03:34 PM

I was thinking more along the lines of commercial shipping than military use.

Scaling it up would be a bear-and-a-half but the increase in efficiency might make it viable.

mapuc · 02-04-22, 03:48 PM

Quote:

Originally Posted by ET2SN

I was thinking more along the lines of commercial shipping than military use.

Scaling it up would be a bear-and-a-half but the increase in efficiency might make it viable.

The vessel is a commercial ship Sailing supply from Esbjerg to the oilrigs.

It's the blueprint you scale up first of all.

Markus

02-04-22, 08:51 AM	#1
Kapitan Sub Test Pilot Join Date: Mar 2005 Location: UK + Canada Posts: 7,130 Downloads: 77 Uploads: 7	Would love to see it but video unavailable __________________ DONT FORGET if you like a post to nominate it by using the blue diamond Find out about Museum Ships here: https://www.museumships.us/ Flickr for all my pictures: https://www.flickr.com/photos/131313936@N03/ Navy general board articles: https://www.navygeneralboard.com/author/aegis/

02-04-22, 01:14 PM	#3
Kapitan Sub Test Pilot Join Date: Mar 2005 Location: UK + Canada Posts: 7,130 Downloads: 77 Uploads: 7	My initial thoughts on this would be it most certainly could be scaled up and also multi bladed (seen some pictures of a 5 blade) Doing a quick bit of research it does seem the cavitation profile would be more concentrated, so the use of a diffuser may be a bonus with it. A lot of warships today use variable pitch screws this would clearly be a benefit as you don't have to rotate the blade eliminating the gearing. The main draw backs I can see: Time to produce, these screws would be more time consuming than conventional ones, plus the casting process would have to be changed drastically too. Critically would the screw be able to take the torque load of say a DDG ? Damage to the screw would mean an entirely new screw rather than a blade switch out, this would require dry docking as opposed to in water blade changes. (rare but does happen) looking at the website they do offer small commercial use of the screw but haven't gone beyond 10m vessels at this time (according to their website) Overall though it would be a good idea to test this on say a auxiliary vessel then maybe see if it can take the torque of a DDG, the reason for the auxiliary is to see if they are better at saving fuel than azipods. From what they are saying it does have benefits in the fuel economy range and it also eliminates gearing to reverse the shaft when going astern. Just my thoughts after a quick read up and watching that video __________________ DONT FORGET if you like a post to nominate it by using the blue diamond Find out about Museum Ships here: https://www.museumships.us/ Flickr for all my pictures: https://www.flickr.com/photos/131313936@N03/ Navy general board articles: https://www.navygeneralboard.com/author/aegis/

02-04-22, 01:22 PM	#4
mapuc CINC Pacific Fleet Join Date: Sep 2003 Location: Denmark Posts: 20,535 Downloads: 37 Uploads: 0	I have scaled up a blueprint of a Mærsk supply vessel-I went to a special shop and got it scaled double up(the blueprint) Did not build it-Sold the blueprint to some other guy on a modelforum. Markus __________________ My little lovely female cat

02-04-22, 03:34 PM	#5
ET2SN Ocean Warrior Join Date: Oct 2017 Posts: 2,652 Downloads: 60 Uploads: 0	I was thinking more along the lines of commercial shipping than military use. Scaling it up would be a bear-and-a-half but the increase in efficiency might make it viable.