Reply
 
Thread Tools Display Modes
 
Old 12-06-2017, 10:19 AM   #1
Veteran Member
 
Join Date: Jun 2010
Posts: 72
Bow thruster vs Stern thruster

Good morning
Looking at Trawlers in the 38ft range. Started looking at single screws as well as the twin screws. I noticed some single screw trawlers had bow thrusters and other only a stern thruster. Id like info on both from those who have them. Which is preferred and why one is preferred over the other.
Thanks
Jim
__________________
Advertisement

jclays is offline   Reply With Quote
Old 12-06-2017, 10:30 AM   #2
Guru
 
OldDan1943's Avatar
 
City: Aventura FL
Country: USA
Vessel Name: Kinja
Vessel Model: American Tug 34 2008
Join Date: Oct 2017
Posts: 597
AT comes with bow and stern thrusters.
__________________

__________________
I used to be a news junkie until I found this place.
Sooo, what's happening in the world and local news?
OldDan1943 is online now   Reply With Quote
Old 12-06-2017, 10:45 AM   #3
Senior Member
 
City: Fairport
Country: United States
Join Date: Jan 2017
Posts: 491
my random thoughts:
Many boats when left to the wind, turn the bow downwind, and it's difficult for a single to "fix" that in limited space. So, it seems the bow thruster would be best for that scenario.
OTOH, some stern thrusters designs are mounted independant of the hull, avoiding that grief, and can be more easily maintained. Reportedly, some can act as forward thrusters, when the prime mover dies; but I'd predict speed is really slow.
Yep, nice to have both!
diver dave is offline   Reply With Quote
Old 12-06-2017, 10:46 AM   #4
Guru
 
Tom.B's Avatar
 
City: Cary, NC
Country: USA
Vessel Name: Skinny Dippin'
Vessel Model: Navigator 4200 Classic
Join Date: Jul 2009
Posts: 5,153
Please do a forum search. This topic has been hashed out (and to death) as many times as an anchor discussion. It never goes well ;-)
__________________
2000 Navigator 4200 Classic
(NOT a trawler)
Tom.B is offline   Reply With Quote
Old 12-06-2017, 10:49 AM   #5
Senior Member
 
City: Westerly, RI
Country: USA
Vessel Name: N/A
Vessel Model: 1999 Mainship 350 Trawler
Join Date: Jan 2014
Posts: 464
Honestly, I've heard of bow thruster only OR Bow and Stern thrusters. I've never seen or heard of stern thruster only. I can't even imagine this being very effective. I have a bow thruster on my single inboard. I'd love to have a stern thruster as well. Over time, I've learned to live without a stern thruster and there are now only a few rare instances where I find it is almost necessary.

I wouldn't want to own a single inboard with NO thruster at all. However, you can learn to be very effective with the 'bump and fill' technique.
Shrew is offline   Reply With Quote
Old 12-06-2017, 11:07 AM   #6
Veteran Member
 
Oldersalt's Avatar
 
City: San francisco
Country: USA
Vessel Name: Pacific Star
Vessel Model: 1990 Grand Banks 32 #834
Join Date: Jun 2016
Posts: 84
Sorry, but a stern thruster only works just fine! My Grand Banks 32 came with one. In close quarters manuevering it does a great job of shoving the stern around. Because it is hydraulic rather than electric, there is no limitation on how long you can run it, when necessary (as you know, most electric thrusters can only run a minute or two before overheating). Also, installation is easier...no big hole through the bow, just some bolts and a couple of hydraulic lines through the transom.
Best
Oldersalt








Quote:
Originally Posted by Shrew View Post
Honestly, I've heard of bow thruster only OR Bow and Stern thrusters. I've never seen or heard of stern thruster only. I can't even imagine this being very effective. I have a bow thruster on my single inboard. I'd love to have a stern thruster as well. Over time, I've learned to live without a stern thruster and there are now only a few rare instances where I find it is almost necessary.

I wouldn't want to own a single inboard with NO thruster at all. However, you can learn to be very effective with the 'bump and fill' technique.
Oldersalt is offline   Reply With Quote
Old 12-06-2017, 11:34 AM   #7
Veteran Member
 
Irish Rover's Avatar
 
City: Kusadasi
Country: Turkey
Vessel Name: Irish Rover
Vessel Model: Fountaine Pajot Greenland 34
Join Date: Nov 2017
Posts: 36
This is an interesting subject and I'm keen to hear the opinions of more experienced members. It's a bit off putting [especially for new posters] to be told go search the forum when they start a new thread. If you've heard it all before then skip the thread and let others get the benefit of the experience of those who are happy to share.
Irish Rover is offline   Reply With Quote
Old 12-06-2017, 11:42 AM   #8
Senior Member
 
Sealife's Avatar
 
City: In transit
Country: From USA
Vessel Name: Sea life
Vessel Model: Krogen 42 #61
Join Date: Nov 2013
Posts: 378
Having put over 4000 hrs on single screw no thruster boats, my opinion:

Stern thrusters only is a cheaper way of adding some control. I feel it is a bit wasted, as I’ve never not been able to control my stern (lots of practice).

Bow thruster would be great, just haven’t had a boat with one, and decided the cost wasn’t worth it after being used to not having one.

Both with a joystick would be heaven, but for me not worth the cost or maintenance etc.

When I had my first single screw inboard, I didn’t know how I was going to manage docking. But being on the water in the Chesapeake bay, I watched the commercial waterman dock all the time with bigger boats and single screws. If they could do it, so could I. Practice, practice, practice.

That way when your thruster(s) don’t work, you won’t be completely screwed.
__________________
Scott

www.caribbeansealife.com
Sealife is offline   Reply With Quote
Old 12-06-2017, 11:49 AM   #9
Guru
 
Nomad Willy's Avatar
 
City: Concrete Washington State
Country: USA
Vessel Name: Willy
Vessel Model: Willard Nomad 30'
Join Date: Oct 2007
Posts: 13,711
When I was longing for a thruster it was for a stern thruster. What made me want a thruster at all was so often when anchoring the wind would blow the bow off so soon my boat was abeam to the wind and the anchor rode was at right angles to the boat. Wished I could bring the stern around behind the bow (wind wise) to anchor normally.

I decided in the end a bow thruster would do as well or better. As Diver Dave says the bow falls off downwind. The reason being the freeboard is much greater at the bow and the side area of the hull underwater is less than aft on most boats. Hence the popularity of “bow thrusters”.

Add to the fact that we already have stern thrusters (rudder) the bow thruster seems most important or desirable of the two. But obviously both would be better. Or a bigger better bow thruster. You’re the buyer Jim. You’re in the driver’s seat.
__________________
Eric

North Western Washington State USA
Nomad Willy is offline   Reply With Quote
Old 12-06-2017, 11:57 AM   #10
Guru
 
Join Date: Oct 2007
Posts: 734
Apart from helping turn the boat around using both bow and stern thrust, the only other use of the stern thruster was to push the stern into the dock to help with lines after the bow line was attached. The bow thruster did most of the work. The stern thruster was of marginal value. Logically, it is much harder to move the stern sideways rather than turn the bow, and to do so effectively takes a lot more thrust. I think many stern thrusters are simply under-powered to help much. The imaginary concept of moving the vessel sideways using bow and stern thrust is simply that - imaginary - unless you own the Queen Mary!!
Chrisjs is offline   Reply With Quote
Old 12-06-2017, 12:00 PM   #11
Guru
 
Nomad Willy's Avatar
 
City: Concrete Washington State
Country: USA
Vessel Name: Willy
Vessel Model: Willard Nomad 30'
Join Date: Oct 2007
Posts: 13,711
Quote:
Originally Posted by Irish Rover View Post
This is an interesting subject and I'm keen to hear the opinions of more experienced members. It's a bit off putting [especially for new posters] to be told go search the forum when they start a new thread. If you've heard it all before then skip the thread and let others get the benefit of the experience of those who are happy to share.
I agree w that mostly IR,
But I advise to go search at times when,
1. The older thread was much more comprehensive and more informative.
2. When the older thread contained specific information that I could not recall and didn’t want to do the work for the newer member.
3. Most often though I identify w the newer member because the search engine is so poor. Perhaps I just don’t know what I’m doing as is often the case on the internet.
__________________
Eric

North Western Washington State USA
Nomad Willy is offline   Reply With Quote
Old 12-06-2017, 12:08 PM   #12
Veteran Member
 
Join Date: Jun 2010
Posts: 72
Quote:
Originally Posted by Irish Rover View Post
This is an interesting subject and I'm keen to hear the opinions of more experienced members. It's a bit off putting [especially for new posters] to be told go search the forum when they start a new thread. If you've heard it all before then skip the thread and let others get the benefit of the experience of those who are happy to share.
Thanks..My thoughts exactly.
jclays is offline   Reply With Quote
Old 12-06-2017, 12:11 PM   #13
Senior Member
 
SaltyDawg86's Avatar
 
City: Carrollton, Va
Country: USA
Join Date: Sep 2014
Posts: 393
Quote:
Originally Posted by Shrew View Post
Honestly, I've heard of bow thruster only OR Bow and Stern thrusters. I've never seen or heard of stern thruster only. I can't even imagine this being very effective. I have a bow thruster on my single inboard. I'd love to have a stern thruster as well. Over time, I've learned to live without a stern thruster and there are now only a few rare instances where I find it is almost necessary.

I wouldn't want to own a single inboard with NO thruster at all. However, you can learn to be very effective with the 'bump and fill' technique.
I looked at an OA that was a single screw and only a stern thruster. As said, the stern thruster seems easier to install and cheaper.

I'm not trying to step on anyone's toes, but, IMO a stern thruster and no bow thruster serves no point and is a waist of money. The rudder on a single screw does the same thing and on a twin screw... Well life is easy on them. A bow thruster is the better decision by far.
SaltyDawg86 is online now   Reply With Quote
Old 12-06-2017, 12:16 PM   #14
Senior Member
 
SaltyDawg86's Avatar
 
City: Carrollton, Va
Country: USA
Join Date: Sep 2014
Posts: 393
Quote:
Originally Posted by Chrisjs View Post
The imaginary concept of moving the vessel sideways using bow and stern thrust is simply that - imaginary - unless you own the Queen Mary!!
Lol I have to completely disagree with that statement. Hundreds, if not thousands of vessels use a bow and stern thruster every day to dock and undock without the assistance of tugs. What makes you believe it's "imaginary" unless you're on the QM?
SaltyDawg86 is online now   Reply With Quote
Old 12-06-2017, 12:27 PM   #15
Guru
 
psneeld's Avatar
 
City: Avalon, NJ
Country: USA
Vessel Name: Freedom
Vessel Model: Albin 40
Join Date: Oct 2011
Posts: 15,887
and I guess a positioning system is for unicorns too...
psneeld is offline   Reply With Quote
Old 12-06-2017, 12:37 PM   #16
Senior Member
 
City: Rockford, IL
Country: USA
Vessel Name: Du NORD
Vessel Model: Albin-25
Join Date: Jan 2014
Posts: 177
One big reason I chose an old Albin-25 with a single fixed screw was because I was hugely impressed with how Maine Lobstermen handle their boats, and wanted to try my hand at it. We had no prior power boat experience, just outboard sailing auxiliary, which of course is a steerable prop. We getting reasonably good at handling our Albin in close quarters and have no need for thrusters..
Moby Nick is offline   Reply With Quote
Old 12-06-2017, 01:08 PM   #17
Senior Member
 
City: Fairport
Country: United States
Join Date: Jan 2017
Posts: 491
I see at least some commercial guys (longliners come to mind) that tend to have, shall we say, more acceptance to violent dock impacts than a lot of yachties desire to have.

So, when I hear such and such a commercial operators do just fine with limited controls, I take that will some grain of salt. Notwithstanding the fact, that these guys do this in all kinds of wind and are well practiced. Nonetheless, they are not worried with polishing the bell every week and rub rail dent repair.
OK, flame suit on!
diver dave is offline   Reply With Quote
Old 12-06-2017, 01:58 PM   #18
Senior Member
 
Rebel112r's Avatar
 
City: Birch bay wa
Country: USA
Vessel Name: Rogue
Vessel Model: North Pacific 42
Join Date: Feb 2013
Posts: 391
On the North Pacific, with both bow an stern thrusters of equal strength, I find the stern thruster moves its end more easily, more push with less effort. Flat rear section of stern, plus being at the extreme end, compared with bow thruster, that is a bit aft and has to push the more vertical forefoot of the bow. I would like to have a larger bow thruster, the stern thruster seems well sized. Also with a helm that takes 5 turns lock to lock, it is a bit of a challenge to move rudder lock to lock to move stern in opposite direction. With stern thruster you can leave the rudder hard over say to port to move the stern to stbd with power, and use thruster to correct to port or vice versa. A jog stick to move rudder quickly would be nice, I can do it with the autopilot control but it is 2 many buttons to push when trying to maneuver in marinas. With twin engines, the need for a stern thruster, is questionable, but still would be nice to have.
Rebel112r is online now   Reply With Quote
Old 12-06-2017, 02:21 PM   #19
Guru
 
AusCan's Avatar
 
City: Adelaide
Country: Australia
Vessel Name: Kokanee
Vessel Model: Cuddles 30 Pilot House Motor Sailer
Join Date: Jul 2012
Posts: 2,095
You learn to deal with whatever you have, whether it be bow thruster, stern thruster, twin engines, or single fixed prop. With enough practice (and a good rudder) they can all do the same thing.

In regard to the choice of bow or stern thruster, go with whatever is best suited for installation on your particular boat.
AusCan is offline   Reply With Quote
Old 12-06-2017, 02:58 PM   #20
Guru
 
Nomad Willy's Avatar
 
City: Concrete Washington State
Country: USA
Vessel Name: Willy
Vessel Model: Willard Nomad 30'
Join Date: Oct 2007
Posts: 13,711
Quote:
Originally Posted by Nomad Willy View Post
When I was longing for a thruster it was for a stern thruster. What made me want a thruster at all was so often when anchoring the wind would blow the bow off so soon my boat was abeam to the wind and the anchor rode was at right angles to the boat. Wished I could bring the stern around behind the bow (wind wise) to anchor normally.

I decided in the end a bow thruster would do as well or better. As Diver Dave says the bow falls off downwind. The reason being the freeboard is much greater at the bow and the side area of the hull underwater is less than aft on most boats. Hence the popularity of “bow thrusters”.

Add to the fact that we already have stern thrusters (rudder) the bow thruster seems most important or desirable of the two. But obviously both would be better. Or a bigger better bow thruster. You’re the buyer Jim. You’re in the driver’s seat.
The “edit” period went so fast I need to quote myself.

Another thought occured to me. In the anchoring situation I was talking about getting knocked back/down w the wind at the bow the boat will assume a position somewhat broadside to the wind. Even if only 45 degrees the bow thrusters will need to push against the wind on the bow whereas the stern thrusters would be aided by the wind force. So the stern thruster may have as much effect as the bow thruster. So re the experience rebel112r one would almost need to find an owner w the same boat or guess or get both and find out. One advantage w both is that both in operation at once pushing in opposite directions would probably rotate the boat quite smartly. I would like that but $.
__________________

__________________
Eric

North Western Washington State USA
Nomad Willy 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





All times are GMT -5. The time now is 07:32 PM.


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