Reply
 
Thread Tools Display Modes
 
Old 09-30-2010, 07:46 AM   #1
FF
Guru
 
FF's Avatar
 
Join Date: Oct 2007
Posts: 16,515
Trailing a prop.

Someone was looking for a shaft brake , so a prop cpould be trailed.

http://www.controlmastersinc.com/kobelt.htm

Makes small (but maybe big enough) for sail boats and BIG ones .

Genuine marine , not Yachtie , so priced accodingly.
__________________
Advertisement

FF is offline   Reply With Quote
Old 09-30-2010, 11:07 AM   #2
Guru
 
C lectric's Avatar
 
City: Somewhere
Country: , Canada
Vessel Name: Island Pride
Vessel Model: Palmer sedan 32'
Join Date: Oct 2007
Posts: 1,860
RE: Trailing a prop.

Shaft brakes come up once in a while. I'm aware of Kobelt and there are others.

As FF points out they are pricey for most of us.

It just occured to me that if one didn't want an auto release/application unit you could simply rig a heavy clamp on collar to the shaft with a disc secured to the collar that had several holes drilled in the circumference and use an arm with a clevis and pin arrangement to a very solid point on the vessel structure, the stringer. That way if someone wanted a prop locked in a specific position for reduced drag it could be done.

Not all vessels of course have the shaft room to do so .
No, I've not done it, twas just an idea.
__________________

C lectric is offline   Reply With Quote
Old 10-01-2010, 04:25 AM   #3
FF
Guru
 
FF's Avatar
 
Join Date: Oct 2007
Posts: 16,515
RE: Trailing a prop.

Go Karts use cheap disc brakes , should someone want to just build a custom disc and mounting setup.

We use a pro built prop brake on out 90/90 that locks into a notch so the prop (2 blade) is indexed properly behind the deadwood.

Std procedure is to hang the start key over the pulled prop brake handle.
FF is offline   Reply With Quote
Old 10-01-2010, 10:01 AM   #4
Guru
 
skipperdude's Avatar
 
City: Whittier AK
Country: USA
Vessel Name: Apache II
Vessel Model: 1974 Donald Jones
Join Date: Oct 2007
Posts: 3,147
RE: Trailing a prop.

What about a piece of chain and a large pair of vice grips.
Worked for me.

SD
skipperdude is offline   Reply With Quote
Old 10-04-2010, 08:33 PM   #5
Master and Commander
 
markpierce's Avatar
 
City: Vallejo CA
Country: USA
Vessel Name: Carquinez Coot
Vessel Model: 2011 Seahorse Marine Coot hull #6
Join Date: Sep 2010
Posts: 10,251
RE: Trailing a prop.

Asking how to stop the propeller from turning?* Just put the transmission in-gear with the engine turned off.* Am I missing something?* This was standard practice when racing auxiliary-powered sailboats.
markpierce is offline   Reply With Quote
Old 10-04-2010, 09:08 PM   #6
Guru
 
C lectric's Avatar
 
City: Somewhere
Country: , Canada
Vessel Name: Island Pride
Vessel Model: Palmer sedan 32'
Join Date: Oct 2007
Posts: 1,860
RE: Trailing a prop.

If you have a mechanical gearbox that would work. Those small gearboxes, Hurth and the like, are mechanical.

Most of the gearboxes here are hydraulic, so putting into gear will have no effect all. It takes hydraulic pressure to lock the clutches or bands. Without the engine running there is no hydraulic pressure. The propellor will freewheel.
C lectric is offline   Reply With Quote
Old 10-04-2010, 09:15 PM   #7
Master and Commander
 
markpierce's Avatar
 
City: Vallejo CA
Country: USA
Vessel Name: Carquinez Coot
Vessel Model: 2011 Seahorse Marine Coot hull #6
Join Date: Sep 2010
Posts: 10,251
RE: Trailing a prop.

Thanks for reducing my ignorance.
markpierce is offline   Reply With Quote
Old 10-06-2010, 10:27 PM   #8
Guru
 
koliver's Avatar
 
City: Saltspring Island
Country: BC, canada
Vessel Name: Retreat
Vessel Model: C&L 44
Join Date: Nov 2007
Posts: 2,165
RE: Trailing a prop.

"Without the engine running there is no hydraulic pressure. The propellor will freewheel."

If you can't turn your props by hand when you are hauled out, it is unlikely your forward motion will turn them, so you won't have to put a brake on if you lose an engine, whatever transmission you have.
koliver is offline   Reply With Quote
Old 10-06-2010, 11:22 PM   #9
Scraping Paint
 
City: -
Country: -
Join Date: Oct 2007
Posts: 13,748
RE: Trailing a prop.

With regards to keeping a shaft from turning if the engine has to be shut down, we simply tie it off. A number or years ago I installed brackets cut from a length of heavy aluminum L-extrusion and mounted them on the underside of the heavy cabin floor beams directly over each shaft coupler. I drilled a hole through the extrusion and mounted a stout shackle in it. So if we have to tie off a shaft (we've had to do it three times in the 12 years we've had the boat) I simply wind a length of strong line around the shaft coupler a bunch of times and tie it off to itself and then run the line up to the shackle and tie it off there.

We then hang "remove before flight" red streamers on the power and shifter levers for that side to ensure we don't start the engine later and inadvertently put the transmission in gear.
Marin is offline   Reply With Quote
Old 10-08-2010, 04:50 AM   #10
Guru
 
Keith's Avatar
 
Vessel Name: Anastasia III
Vessel Model: Krogen 42
Join Date: Oct 2007
Posts: 2,716
RE: Trailing a prop.

Those vice grips that incorporate a bicycle type chain will work well.
__________________

Keith is offline   Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
help with prop # olesouth Power Systems 4 03-01-2012 12:54 AM
Prop fouling SOMERS General Discussion 11 03-11-2011 06:20 PM
Four blade prop awpptdt Power Systems 2 12-14-2010 06:20 PM
Prop...... dwhatty Power Systems 24 05-08-2010 12:24 PM
New prop Phuket Custom Builds & Refit Projects 1 03-09-2009 08:42 PM




All times are GMT -5. The time now is 10:24 AM.


Powered by vBulletin® Version 3.8.8 Beta 4
Copyright ©2000 - 2017, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0
Copyright 2006 - 2012