Retractable Marine Drives

Many sailors would like to have a 'retractable propulsion system' to eliminate that excessive drag of conventional 'fixed' prop/shaft systems. There have been a number of different systems worked on in the past few years, but mostly custom systems that have not reached any production status.

I even suggested one utilizing a 'rim drive propulsion unit' ,
http://www.runningtideyachts.com/dyn...Rim_Drives.php

.....but development efforts on these rim drive units dropped off significantly during the depressed yachting market following 2008.
Just to clarify, there is a distinction between the '(bow)thruster units, verses the propulsion units. The thruster market has progressed along, but little work has been put into the propulsion units.

I was just doing a little research on retractable propulsion units and ran across this mention:
http://www.shippingandmarine.co.uk/a...39&issueid=454

Anyone know where we might find some photos and more details on these units?

As you say there are some custom units out there, its just tough to find out about them in any detail as they are so 'one-off'

The reason I found that reference above to the Ocean Yachts System unit was thru a google IMAGES search for 'retractable marine drives'. Sometimes its amazing where google IMAGES can take you.

Thanks for that info.
They don't address any details as to how the power gets transferred from the engine to the propeller unit. This might be particularly interesting in that the prop unit can rotate around its vertical axis under power.

I did just find this statement on this page:
http://www.***********/unfurled/#unfurled

They refer to them as 'thrusters' rather than propulsion units?
And they say they are direct drive??


Hydraulic Steering Feedback System
I also found the hydraulic feedback system of there's very interesting as well

BTW I just received an answer from OceanYachtSystems that their units were:, " Hydraulic in deployment, rotation and propulsion."

I thought my concept incorporated a minimum use of space, ....particularly if you viewed it from a profile view:



....of course that was if they could produce a reasonable size rim drive PROPULSION unit

Piston Boxes for Retractable Rim Drive
BTW, the tops of those 'piston boxes' that housed the rim drive units were above the load waterline of the vessel, so the rim drive units might be extracted from the vessel for servicing even while the vessel was still afloat in the water.
Attached Thumbnails

Wärtsilä launches retractable thruster
not exactly sized for our yachts, but the concept is expanding

Anything new in retractable drives?

What type of twin screw system?? Your reply doesn't tell us much

Wondering what happened to the images that were referenced here,....and in the subject thread above??