Bow Thruster and Stabilizers, are they necessary?

[Freestyle]

I treat the thruster like the tugs when I drove an aircraft carrier. Figure out how the engines will move the ship and then use tugs to fix the wrong answers.

The goal is to operate safely and anything that furthers that is good.

Sky Anchor and Joy stick operations now allow lower skill level owners to operate more safely. These guys will use the joystick to guide them to the slip, turn on Sky Anchor, and walk around the boat tying lines solo. While we may not need this technology or envy them for having it, they feel the same way about our ability to walk a boat using the transmissions and split throttle controls.

My one point of contention is when waiting at bridges and locks with the new SkyHook boats. The rest of us drift with the wind and tide while we wait. SkyHook boats park and become fixed objects for us to navigate around thereby messing up the historical order of things. As SkyHook boats proliferate, our boats will look older and more dangerous to the new buyers.

Unless you can beat them, I suggest joining them as its safer for all of us.

Bruce

Freestyle
1986 62 CPMY (53 with ext)
Tampa

 

[madhatter1]

Last week anchored out at Johns Pass there was a boat behind us using skyhook. There was a decent current. Me, I'm thinking it's better to anchor to hang out. But to each their own.

But then they decide to go swimming. These morons are swimming off of and around a boat that is running and shifting in/out of gear.

 

[tjshuler]

Center the rudders, keep your hands off the wheel, use shifters to turn the boat. Had a 43DC and now have a 53MY. Both are very easy to maneuver while docking and other close quarter activities. The only difference is the 43 would get pushed by the wind. The 53 is just enough heavier that it is not affected by the wind much. Executive summary: Bow thruster not required.

No stabilizers on the 43, stabilizers on the 53. As neither are "deep V" like a Bertram, they can get a pretty good roll going. Stabilizers are recommended. But you don't want to add them. Crazy expensive.

 

[Captain Ralph]

Last week anchored out at Johns Pass there was a boat behind us using skyhook. There was a decent current. Me, I'm thinking it's better to anchor to hang out. But to each their own.

But then they decide to go swimming. These morons are swimming off of and around a boat that is running and shifting in/out of gear.

I remember working (SeaTow) the area just S, S/E of Stiltsville. Big party sand bar.
Bunch of folk were yelling at this one boat. As I idled a lil closer, I could make out the activity.
Instead of dropping a hook in shallow water, this one fancy new looking boat was using skyhook (or like) and kids were jumping in and crawling out the back of this one boat. Also, so much for crystal clear water.

Somebody had already got the attention of a park officer and he came speeding in and stopped it.
I was further contacted to stand by for a tow back to Blacks Point. I did not get the details but the owner/operator was not cooperative, arrested and somebody else drove the boat away.

This was many years ago when computerized pods were just coming into market.

I cringed that day and still cringe thinking about it.
Could of been a nice billable tow also.

 

[Pascal]

Center the rudders, keep your hands off the wheel, use shifters to turn the boat. Had a 43DC and now have a 53MY. .

Don’t overlook the benefits of rudders. They will help kick the stern out faster than split gears alone. Not necessary but useful

 

[JD5652]

Ran my 44' sportfish for 20+ years without thruster or stabilizer. Since this boat was a planing hull... no real need for stabilizers. I had 4-blade props and could get into/out of almost any tight spot and put the boat wherever I wanted.

Now I have a 58 LRC and it's a different ball game for me. My transmissions are 3:1... so at 600 RPM idle I only have 200 RPM worth of thrust going across the rudders and off the props. I often need a little power when close quarter manuvering. The boat also only has 3 blade props. I never needed the wheel with my sportfish but there are times that I probably need some wheel with the 58 LRC but I not very adept at that quite yet after two seasons.

I like having the thruster on this vessel as well. Since it was installed on the boat when I got it, I use it.

The boat weighs in north of 50 tons... so it takes a bit to get her moving in the direction you want... and then takes a bit to stop her from moving.

The boat had the stabilizers removed and I've run her for two seasons without it... I could take the roll while underway... but sometimes the crew and passengers ... not so much... so I bit the bullet this winter and had them installed. No real world operating experience yet, but I'm sure they will make a pretty big difference in ride comfort for this vessel. Since she is a full displacement hull... round chine... running slow ... and weighing a lot... I believe the stabilizers will be a nice addition to the enjoyment of the boat.

Capt Ralph -

I might take you up on some of those lessons....

 

[Captain Ralph]

Now I have a 58 LRC and it's a different ball game for me. My transmissions are 3:1... so at 600 RPM idle I only have 200 RPM worth of thrust going across the rudders and off the props. I often need a little power when close quarter manuvering. The boat also only has 3 blade props. I never needed the wheel with my sportfish but there are times that I probably need some wheel with the 58 LRC but I not very adept at that quite yet after two seasons.

Just curious, What diameter are your LRC wheels?
3 big (large area) blades?

I know you do have some boat below the water line, I recall a fat keel also.

I did push a brokers LRC around the Huckins dock once. Slow but doable.
I did an ole trick that may help you, Give the helm one turn in the direction you want the boat to twist. Like clutching around a corner. Remember to move it back.
I also to this to help bias the boat into the wind or helping the lean on a pile.
As Pascal mentioned, it kicks the stern out a lil more but at least one end of the boat is moving to help the deeper hull turn. Just watch your stern well. Remember to move it back before your next trick.

 

[JD5652]

Just curious, What diameter are your LRC wheels?
3 big (large area) blades?

I know you do have some boat below the water line, I recall a fat keel also.

I did push a brokers LRC around the Huckins dock once. Slow but doable.
I did an ole trick that may help you, Give the helm one turn in the direction you want the boat to twist. Like clutching around a corner. Remember to move it back.
I also to this to help bias the boat into the wind or helping the lean on a pile.
As Pascal mentioned, it kicks the stern out a lil more but at least one end of the boat is moving to help the deeper hull turn. Just watch your stern well. Remember to move it back before your next trick.

Wheels are 36" x 34" 3-blade.... 6' draft with full keel... she's pretty susceptible to a strong current....

 

[Captain Ralph]

Looks easier than the bottom of my beast. Ours are 32 x 32.
IMO, you should be able to turn very well.
I think the 58 LRC at Huckins I moved once was pretty fouled also.

Here is our bottom. She spins well for an ole 58 x 18.

 

[JD5652]

Looks easier than the bottom of my beast. Ours are 32 x 32.
IMO, you should be able to turn very well.
I think the 58 LRC at Huckins I moved once was pretty fouled also.

Here is our bottom. She spins well for an ole 58 x 18.

I'm liking those 4-blades.... was a game changer for me on my sportfish when it came to close quarters manuvering.....

 

[Captain Ralph]

I'm liking those 4-blades.... was a game changer for me on my sportfish when it came to close quarters manuvering.....

Factory spec. Still a slow boat. But works great with out thrusters.

Now, your monster 36" wheels should work great. However, I really don't see a lot of surface area over a stock 3 blade wheel, say for a Huckins for example. It may be just the angle of the photos, The painted wheels on the hard deck look like the blades do have more area.
I do wonder, even with 3:1 ratio, would a 4 blade wheel get you any thing better, forward and/or side ways?

 

[cww]

I'm liking those 4-blades.... was a game changer for me on my sportfish when it came to close quarters manuvering.....

The difference is probably also power. One 8v71ti in a 53 has just shy of 3 times the horsepower as both of the 4-71na's in an LRC combined. You have less power to move more boat. My boat at idle around the dock there is enough thrust that you have to just bump in and out of gear for 1-2 seconds, that's all you need. On a LRC I can see the utility of the thrusters and would want them if I had one. On a trawler large engines run counter to the design purpose of fuel efficiency.

 

[jim rosenthal]

Ralph, how large do the rudders have to be to be able to walk a boat sideways? I have tried to learn to do this with my boat, but never succeeded. (36 convertible) Is it possible to do it with a boat such as mine?

 

[Captain Ralph]

Ralph, how large do the rudders have to be to be able to walk a boat sideways? I have tried to learn to do this with my boat, but never succeeded. (36 convertible) Is it possible to do it with a boat such as mine?

One of those tricks I never mastered and don't miss.
For another reason, I added 2" to the back edge and 2" to the bottom of my rudders. I can just move her sideways but it is not pretty. Wiggle side ways is more like it.
I am not the answer guy on this.
I would be poorly trying to remember how I made my last attempts at doing so, long ago.

Before our Bertram, we had a Pequod 34. LBC and V drives. I remember pushing that boat sideways, but as to say how, those brain cells have long ago fallen.

 

[Pascal]

Trawlers incl LRCs don’t have the torque and are slow to react. Often need to bump RPM a bit. The bigger the engines and wheels the shorter time you keep it in gear

As to walking a boat, I ve tried a few times and pretty much gave up. It s a useless trick since you re not going to walk the boats in any kind of breeze. Not worth it. With twins when pinned you can just lean the bow on a piling and swing out the stern. That works just as well as a thruster. Well till you hit 70/80’ when it puts too much stress on the pilings and rub rail

 

[JD5652]

Trawlers incl LRCs don’t have the torque and are slow to react. Often need to bump RPM a bit. The bigger the engines and wheels the shorter time you keep it in gear

Agree.... in my sportfish... when I put her in gear she would "squat" even at 600 RPM idle .. she had 1.5:1 tranny ratio... and was VERY responsive.... my 58 LRC has 671 naturals... when I put her in gear... seems I have to wait 1-2-3 seconds before she even thinks about responding... and then it's in what I would call a "sluggish" reaction... but those are two completely different vessels...

Getting back to the original question a bit... I do use my bow thruster to ease my approach when docking on a t-head and being blown onto the dock... it's easy to do damage to either docks or the boat when that 50 tons gets into motion ...

 

[Pascal]

Couple a years ago I was without the bow thruster on an 84 footer for about 3 months. Easy to handle with 42” five blades but indeed coming back on the tee head sometimes required flaring when landing. I would come in at an angle so I could slow the bow with the gears and then slow the stern switching the gears.

 

[Dan Mapes]

This seems a bit off topic. We were supposed to be talking about 43 MYs / DCMYs. Freedom had 6-71 TIs and 4 blade props. I always thought it reacted just fine and rarely, if at all did I have to bump off idle when docking.