Bow Thruster

[geezer]

I've found this forum so helpful with my questions, I'll go to the well once again for your thoughts. *A friend and I bought a 37' Puget Trawler Europa, single engine, last spring and after a season of herding it into places it didn't want to go (especially if the wind is blowing)*we have decided it is worth the money and piece of mind to install a bow thruster. (at my age, ease and safety takes precedence over the challenge).

We have pretty much settled on a Lewmar 185TT 12V, but need some advice on going with a mdl# 4.0 (5.4 hp) or the mdl 5.0 (6.7 hp). It's not a money saving problem, after figuring the total cost, the difference in price between the two is not that much of an issue. *We were more interested in other problem that might be encountered by going with the larger/smaller thruster. Thanks again,
Geezer

 

[sunchaser]

Earlier this year I had a Lewmar thruster installed. The*decision made was to install the biggest kW that would fit within the bilge space. In my case this was about an 8kW 24V unit. So, I'd *go with the 5 kW unit

 

[Doc]

Trust me, you cannot install too large a bow thruster.

 

[Fotoman]

Yep, I have to agree with Doc. Well worth the extra money. And I'm guessing a small burst of a more powerful thruster takes less power than a longer burst of a smaller unit (just an educated guess here, others might have some data to confirm that theory of mine).

As I'm gaining confidence with handling my boat I use the thruster a lot less but it's always nice to have it when you need it. You won't regret it.

 

[Steve]

Like the others I believe a bow thruster is well worth installing, a good sized one too. Try to use it as little as possible to keep up your docking skills. You may get some razzing from bystanders who call using one cheating, don't give it a second thought.
Good luck,
Steve W.

 

[Codger2]

I have one and I agree with everything that's been said. Wish I had the next size up.

 

[Carey]

There is no such thing as too large or powerful when it comes to thrusters. I have one and although I don't use it much, it can be helpful, and mostly when there is a wind blowing you off the dock. I have had several occasions when it wasn't big or powerful enough.

 

[geezer]

OK, the bigger one it is--thanks again for everyone's input.
I'll get a picture posted of our pride and joy, but Fotoman's Marine Trader is a slightly smaller twin to ours. What a great forum and wonderful asset for us newcomers. Thanks.
Dave

 

[Arctic Traveller]

One thing no one mentioned, but the power requirements will be greater for the bigger motor.** Make sure you have a well thought out scheme to charge all your batteries, including the new one(s) you'll have to install.* .............Arctic Traveller

 

[geezer]

Thanks Jeff, I'll do some research on what we'll need.

 

[FF]

I'll do some research on what we'll need.

The first question is "how long" can it operate before it must cool off for how long?

Many electric units have very short operating times (usually not given till treading the operating instructions).

Hydraulic is always the best, but not cheap, unless it has more than one use.

Bow or stern thrusters , windlass , dink hoist , cruising AC generator , reefer and many other items can be Hyd operated with usually better results than DC.

 

[rwidman]

From what I've read, installing a bow thruster is not a DIY job, even for an advanced DIYer. So - you're going to have to call in a specialist. These people will be able to give you advice and choices for your boat and your intended use.

I agree with the others though on oen point, bigger is better. I wish mine were the next size up.

 

[Baker]

Generally, the max operating time for a consumer grade electric 12v bow thruster is 3 minutes.....at least that is what it is for my Side Power thruster. 3 minutes is PLENTY and if you need 3 minutes worth then I think you might need to rethink your docking strategy.

 

[Doc]

John, my noble man, I understand your point but 3 minutes goes by pretty darn quick when the wind is piping up and you are in a strange marina and the only way to dock is to turn the boat 180 degrees so that you can get something you need like power or say you want to facing a certain way. Sure you can do a temporary job and move the boat later. But if you are coming in and the weather has gone south on you, the boat needs to be planted.

I belong to a Florida Yacht Club and most clubs have only 3 or 4 transiet slips...where you are going to go whether you like it or not

I have wished many times for a bigger, longer lasting (several things) thruster.

 

[Baker]

Still not buying it....

....People without Bow Thrusters can be in the exact same situation and somehow nobody dies and their boat doesn't sink. A bow thruster should be considered a luxury...not a necessity(in boats or our size range and application). IOW, it should supplement good boat handling skills....not replace them.....IMO

-- Edited by Baker on Tuesday 7th of December 2010 10:57:36 AM

 

[Doc]

I too will stick to my guns on this one. M boat has a fairly deep draft, a full keel and a small rudder so at dead slow speed it only responds to rudder with bursts of power. I have plenty of control going down fairways at idle, however. I cut my teeth on a single engine Albin 33 before bow thrusters were even thought of so I know the 'back and fill" method. I can do that on this boat but only with enough power to throw passengers backward off their bar stools.

I understand your opinion completely, but next time you are going into Midway on a windy day why don't you try it without flaps?

-- Edited by Doc on Tuesday 7th of December 2010 12:57:15 PM

 

[Baker]

Give me enough runway and no Problem! And if we are ever going into Midway, it is not a good day......

..as I typed that I realized you meant Chicago "Midway"...not the Island in the middle of the Pacific. I fly over the Pacific Island more than I do the Chicago version. It is usually one of our ETOPS alternates going from HNL westbound.

PS...I am thinking you could consider flaps on a jetliner as a necessity and not a luxury....much like a bow thruster would be considered a necessity on a 900ft ship.....although they could still get help from the harbor tugs.

Regardless of necessity.... 3 minutes on a small recreational boat should be more than adequate.

 

[markpierce]

Baker wrote:

Give me enough runway and no Problem! And if we are ever going into Midway, it is not a good day......

..as I typed that I realized you meant Chicago "Midway"...not the Island in the middle of the Pacific. I fly over the Pacific Island more than I do the Chicago version. ...

Midway Island was also attacked on Dec. 7, 1941.

*

 

[Gulf Comanche]

Mark:
I thought you were wrong about Midway so I looked it up. You are correct sir, and I learned something new, as follows:
The location of Midway in the Pacific became important to the military. Midway was a convenient refueling stop on transpacific flights, and was also an important stop for Navy ships. Beginning in 1940, as tensions with the Japanese were rising, Midway was deemed second only to Pearl Harbor in importance to protecting the U.S. west coast. Airstrips, gun emplacements and a seaplane base quickly materialized on the tiny atoll. The channel was widened, and Naval Air Station Midway was completed. Architect Albert Kahn designed the Officer's quarters, the mall and several other hangars and buildings. Midway was also an important submarine base. Midway's importance to the U.S. was brought into focus on December 7, 1941 with the Japanese attack on Pearl Harbor (Midway was also attacked for the first time on December 7, 1941). A Japanese submarine bombarded Midway on February 10, 1942.[4] Four months later, on June 4, 1942, a naval battle near Midway resulted in the U.S. Navy exacting a devastating defeat of the Japanese Navy. This Battle of Midway was, by most accounts, the beginning of the end of the Japanese Navy's control of the Pacific Ocean.

 

[Carey]

Baker wrote:

A bow thruster should be considered a luxury...not a necessity(in boats or our size range and application). IOW, it should supplement good boat handling skills....not replace them.....IMO

-- Edited by Baker on Tuesday 7th of December 2010 10:57:36 AM

John You are so right. I would even go so far as to say that if one buys a boat
with a thruster, they should forget it's there for the first year or two. One thing I
see more and more these days is people coming into a side tie situation and
positioning themselves parallel to, but far away from the dock, and then using
the thruster and a combination back and fill to get to the dock. It's absolutely
tortuous to watch.


And then there is the boater who will be cruising through the harbor attempting to
steer each turn with the thruster. It's not what they are intended for. I want to hand them the business card of a qualified captain, willing to teach a novice.


In all honesty, before even chartering my first inboard boat, I sought took the advice of a captain friend, and chartered a boat not unlike the Prairie 29 for a three hour training, and all we did was approach and place the boat in every available empty slip in the marina. My captain friend guided me through each new scenario, and then left me to do the next few similar approaches on my own. Not to toot my own horn, but after that session, I was running inboards better than many who had been utilizing their own self taught bad understanding of physics.


Sorry I went a little astray with this, but one thing leads to another.

*



-- Edited by Carey on Tuesday 7th of December 2010 11:46:32 PM

 

[hollywood8118]

Baker wrote:Regardless of necessity.... 3 minutes on a small recreational boat should be more than adequate.

John, I will side with you on this,
the bow thruster on Volunteer was installed by the P.O. ... and it was undersized for the task. It was a 24v unit... but still not enough power in a big beam wind.... but still ... in 8 years of ownership I never used the thruster for 3 minutes in a hour ( I believe that was the rating limit ). I spun all 60,000 lbs 180 degrees on more than a couple occasions and used the thruster to even bring the boat into the marina and back into my slip after a steering failure.
If you need to use a thruster more than 3 minutes ( total run time ) you are doing something wrong. In a perfect world my boat would of had a hydraulic unit... but it was not worth changing it
HOLLYWOOD

*

 

[geezer]

Gulf Comanche wrote:

This Battle of Midway was, by most accounts, the beginning of the end of the Japanese Navy's control of the Pacific Ocean.

Makes a person sort of wonder it the Japanese could have done better if they had the addition of bow thrusters.

*

 

[hollywood8118]

Carey wrote:

*
john You are so right. I would even go so far as to say that if one buys a boat
with a thruster, they should forget it's there for the first year or two. One thing I
see more and more these days is people coming into a side tie situation and
positioning themselves parallel to, but far away from the dock, and then using
the thruster and a combination back and fill to get to the dock. It's absolutely
tortuous to watch.

Carey,
I am going to call B.S. on this....So what is wrong with bringing a heavy displacement boat next to the dock and walking the stern with prop walk and counteraction with a thruster?? is this not what is was designed for??* I guess one could bring a twin screw boat to the dock and only use one engine ... would that make one a better skipper or is it just showing off?. Volunteer with her 6' draft and full keel and 60,000 lbs. is a hand full in tight spaces... the thruster is worth at least one additional crew... and it doesn't complain!.** I personally enjoyed "parallel parking" between boats when I only had 5' or so of maneuvering room off the bow and stern and getting her next to the dock and tied off while piloting solo... I would never of attempted the same without a thruster... can I line the boat up next to the dock... you bet... I would do that too... with the Admiral handling the lines on the dock. But it always pissed her off... she figured I was just showing off... and would raz me for NOT using the bow thruster!.** I have also found that most of the time people that make the " they should go for a couple years without using the thruster to learn how to drive the boat " ..statement don't have a bow thruster!
what next.... don't turn on the chartplotter and gps and get out the paper charts and dividers??
HOLLYWOOD

*

 

[markpierce]

Gulf Comanche wrote:

Mark:
I thought you were wrong about Midway so I looked it up. You are correct sir, and ...

The aircraft carrier (museum) Midway:

*

 

[markpierce]

hollywood8118 wrote:

....So what is wrong with bringing a heavy displacement boat next to the dock and walking the stern with prop walk and counteraction with a thruster?? is this not what is was designed for??* I guess one could bring a twin screw boat to the dock and only use one engine ...

I'm with you Hollywood.* And I don't want to hear/read twin-propeller owners disrespecting single-propeller guys*who opt to have a thruster.* And for those single-propeller, sans-thruster*fellows, don't be uppity.* Try berthing a sailboat without the engine where you usually only have one try.

*


-- Edited by markpierce on Wednesday 8th of December 2010 12:36:26 AM

 

[Carey]

hollywood8118 wrote:

*
Carey wrote:

*
john You are so right. I would even go so far as to say that if one buys a boat
with a thruster, they should forget it's there for the first year or two. One thing I
see more and more these days is people coming into a side tie situation and
positioning themselves parallel to, but far away from the dock, and then using
the thruster and a combination back and fill to get to the dock. It's absolutely
tortuous to watch.

Carey,
I am going to call B.S. on this....So what is wrong with bringing a heavy displacement boat next to the dock and walking the stern with prop walk and counteraction with a thruster?? is this not what is was designed for??* I guess one could bring a twin screw boat to the dock and only use one engine ... would that make one a better skipper or is it just showing off?. Volunteer with her 6' draft and full keel and 60,000 lbs. is a hand full in tight spaces... the thruster is worth at least one additional crew... and it doesn't complain!.** I personally enjoyed "parallel parking" between boats when I only had 5' or so of maneuvering room off the bow and stern and getting her next to the dock and tied off while piloting solo... I would never of attempted the same without a thruster... can I line the boat up next to the dock... you bet... I would do that too... with the Admiral handling the lines on the dock. But it always pissed her off... she figured I was just showing off... and would raz me for NOT using the bow thruster!.** I have also found that most of the time people that make the " they should go for a couple years without using the thruster to learn how to drive the boat " ..statement don't have a bow thruster!
what next.... don't turn on the chartplotter and gps and get out the paper charts and dividers??
HOLLYWOOD

*

Hollywood

I stand corrected. I was speaking of boats closer to my size. Let's say up to forty feet. The parallel parking actually eludes me with any size boat, as I don't see why one would not nose your bow in as close to the dock as you can before beginning the back/fill/thrust. With a keel and a good sized rudder, the whole process can be done without thruster, so why begin thrusting fifteen feet away from the dock?


*

 

[Baker]

Yep....that is my technique...hang the bow over the dock and hit reverse and the prop walk bring it around...and a little forward thrust to keep the momentum going and then a bump of the thruster to snug it in. *Mainship is not known for overbuilding or overpowering anything....but the thruster in this thing is surprisingly powerful for a boat of this size....it will take the feet out from under someone standing on the bow....maybe they had their target market in mind...

-- Edited by Baker on Wednesday 8th of December 2010 11:44:26 AM

 

[Phil Fill]

We have a hydraulic bow thruster which we can run for hours as the hydraulics are design to be a get home also. **Our is more of the jet drive like some of the bigger ferries/ships as it was made by Omnithrust, *http://www.omnithruster.com/* and it also has a forward thrust to be used as a get home.* However, I do wish it had more thrust.* The weak link is being powered by the gen set which operates the thruster at 50%.* If when we have to replace the gen set it will be based on HP not KW.*
*

*
I can turn the boat 360 degrees with the thruster, but in 20+ knot winds it tough.* Then I have to use the stern prop thrust and the prop walk.* But we have a 6 ft draft, 40 tons and a high air draft.*I have kept it running for over an hour holding us in place waiting for the locks.*I wish we had a stern thruster also.

-- Edited by Phil Fill on Wednesday 8th of December 2010 10:20:48 PM

 

[sunchaser]

On my 48 footer with twins, *the newly added thruster is a plus. As others have noted, I too can now walk the boat sideways with little/no space forward or aft needed. Maximum time "on" this year was about 5 - 10 seconds per shot, where does 3 minutes come from? You should be on* your second martini after 3 minutes!!

 

[Baker]

And I think I can see the USS Ronald Reagan off of the bow of the Midway....