Thruster questions

[FatBear]

My wife is rebelling about handling lines since she hurt her elbow in France (doing a flight of 12 locks - not exactly easy on anyone.) We are considering a larger boat than we've had in the past and I will need to be able to moor it myself much of the time. I don't expect much trouble most of the time, but once in a while ...

So I need to learn about bow and stern thrusters. Are they on/off or variable thrust? Are there any that you can leave on for longer periods than just for short bursts?

My idea is that when the wind is wrong, or whatever else can go wrong, I could put the boat up against the dock and apply just enough thrust to hold it there while I go ashore with the lines. This would require that they have variable thrust so I don't snap off a slip finger and would require that they could remain on for a few minutes while I took over a couple of lines.

Does this make sense?

Alternatively, I understand that there are wireless remotes for some thrusters. Perhaps I could use something like that to keep the boat against the dock, though it would be really bad if something went wrong while mooring to a side-tie with the wind blowing the boat out.

Are hydraulic thrusters more reliable than electric and can they vary their thrust and do they have longer run times than electric? I just remember seeing an engraved placard next to an electric bow thruster control limiting it to 15 seconds every minute. Plus, I like hydraulics. Please feel free to correct me if you think I should hate them.

Thanks.

 

[Comodave]

Look at Side Power thrusters. They have an addon that allows the thrusters to run at a variable speed so you can run them for extended times. They have a wireless remote so you can hold the boat to the dock while you step off to handle lines. I put one in our last boat on the stern. Worked great just make sure you go big enough. I went one size larger than the chart said.

 

[FatBear]

Thanks Comodave!

Does my basic concept seem sound?

 

[Bacchus]

I agree with Dave.
I have SidePower bow & stern but they are the older on/off. I understand there is a retrofit upgrade for proportional control but haven't seen the need for my use. I think the newer models are available as proportional. With bow & stern I tend to alternate ends to avoid prolonged use of either one.
I added the wireless remote in prep for a 2019 cruise where we traversed over 100 locks and the remote proved very handy assisting my mate in wind & turbulent conditions.
The remote is also handy retrieving anchor as mate handles shifter (single screw)from helm and I can run windless and thruster at bow to maintain alignment until retrieved.

 

[Comodave]

With the proportional addon you can run them up to 20 minutes, I think. It would certainly make docking and undocking much more easy.

 

[Lepke]

If your boat is big enough to justify, hydraulic thrusters can run indefinitely. Lots of power without all the electrical problems.

 

[FatBear]

"Bigger" for us means 41-44 feet. I was googling around and came across a sizing chart that showed some hydraulic thrusters for boats as small as 30 feet, which I suspect would be considered small in this context. But most boats that we see that do have thrusters have electric ones.



So I'm curious: why would you only use hydraulic on a larger boat and not on a smaller one?


They need some sort of pump, reservoir, or a powerhead that combines both. But the electric thrusters need extra batteries and charging circuitry for them. Probably the powerhead is more expensive than the batteries.


They need hydraulic lines, but the electric ones need cables. Probably the hydraulic lines are more expensive.


The hydraulic motor ought to be considerably less expensive than the electric one. At least industrial ones are very inexpensive. Don't know if this would offset the other increased costs.


I don't know which is noisier. Obviously the hydraulic pump/powerhead must be running whether you are thrusting or not, while the electric is silent when it is not thrusting. Hydraulic motors tend to be kind of screechy, but electric ones can also be.


Hydraulic lines can leak, but if you do them right they shouldn't. Batteries can off-gas hydrogen when they are charging, and hydrogen in the bow compartment near an electric motor seems like a bad idea.


I could go on guessing, but maybe someone knows the real answer.

 

[Flatswing]

Thanks Comodave!

Does my basic concept seem sound?

Yes: Sidepower bow & stern thrusters with remote lanyard are invaluable for us. I single hand frequently & spouse isn’t hauling lines attached to 67,000 lb boat. Proportional control is nice but to be honest, I mainly use short bursts 1-2 secs. Rarely more than 5-10 secs. Depending on load & voltage, thermal cut outs activate somewhere between 30 secs & 2 mins continuous, but I have never hit that threshold.

 

[Jeff F]

Bigger boats may have other powerful devices running on hydraulic, like the windlass, deck wash, stabilzers, trap hauler, etc.

In your size range electric will be far more common, and perfectly effective if installed and managed properly.

I'd echo the suggestion for a wireless remote. No need for variable thrust IMO. Short bursts work fine.

If you have to stay against a pier power up on a spring line rather than relying on the thrusters.

 

[Portage_Bay]

If your primary interest in thrusters is your wife's understandable reluctance to handle lines I'll offer another solution. Have her learn to be a competent boat handler so that you can handle the lines. I've seen that work out quite well.

Also consider the risk of stepping off to make up the lines while depending on thrusters and possibly remotes to keep the boat to the dock. If she's not able to handle the boat and something goes wrong you both now have a very serious problem.

I've seen a situation where the husband was on the dock, the wife who couldn't handle the boat left on her own because the boat got away from him. Fortunately it ended well.

Another benefit of her becoming a good boat handler is it will very likely increase her interest in boating. I've seen that happen as well.

Back to your questions regarding hydraulics. So much depends on what drives the hydraulic pump. If electric will you require the gen running? If a PTO will it be off the gen or the main engine. If off the main will you need to keep the RPMs up to effectively power the hyd pump?

Setting up electric thrusters on a boat that doesn't already have a hydraulic system is much simpler.

 

[FatBear]

If your primary interest in thrusters is your wife's understandable reluctance to handle lines I'll offer another solution. Have her learn to be a competent boat handler so that you can handle the lines. I've seen that work out quite well.

Ain't gonna happen. I've tried to get her to learn to drive smaller boats (18' and 28') and she will not. She likes riding and such, but does not have any interest in driving. Her choice, not mine.

Also consider the risk of stepping off to make up the lines while depending on thrusters and possibly remotes to keep the boat to the dock. If she's not able to handle the boat and something goes wrong you both now have a very serious problem.

Yes, I have thought about that, too. I have pretty good situational awareness. If one or both thrusters die and the boat is not in gear, it isn't going to go zooming off immediately and I should be able to get back on board quickly enough. Especially if I carry a line over with me when I step onto the dock or toss one, first. Worst case, as long as she doesn't put the boat into gear, I know how to swim. If she does put the boat into gear with me on the dock, well I guess that would be a sign of a bigger and non-nautical problem.

Back to your questions regarding hydraulics. So much depends on what drives the hydraulic pump. If electric will you require the gen running? If a PTO will it be off the gen or the main engine. If off the main will you need to keep the RPMs up to effectively power the hyd pump?

Setting up electric thrusters on a boat that doesn't already have a hydraulic system is much simpler.

Thanks, that all makes sense. All of my larger boat experience has been on much larger boats such as 100'+ tugs and larger schooners. They all had hydraulics with dedicated powerheads run either off of an electric motor (most) or a small diesel (one of them.) I wondered about running a pump off of the main engine of a 40' or so boat, but you are right that it would have to keep its RPMs up which would interfere with maneuvering to the dock or into the slip. Electric wins for pleasure boats of this size.

 

[Seevee]

Ain't gonna happen. I've tried to get her to learn to drive smaller boats (18' and 28') and she will not. She likes riding and such, but does not have any interest in driving. Her choice, not mine.


Yes, I have thought about that, too. I have pretty good situational awareness. If one or both thrusters die and the boat is not in gear, it isn't going to go zooming off immediately and I should be able to get back on board quickly enough. Especially if I carry a line over with me when I step onto the dock or toss one, first. Worst case, as long as she doesn't put the boat into gear, I know how to swim. If she does put the boat into gear with me on the dock, well I guess that would be a sign of a bigger and non-nautical problem.


Thanks, that all makes sense. All of my larger boat experience has been on much larger boats such as 100'+ tugs and larger schooners. They all had hydraulics with dedicated powerheads run either off of an electric motor (most) or a small diesel (one of them.) I wondered about running a pump off of the main engine of a 40' or so boat, but you are right that it would have to keep its RPMs up which would interfere with maneuvering to the dock or into the slip. Electric wins for pleasure boats of this size.

You are NOT stepping off the boat before it's secured to the dock are you? If so, that's a HUGE no/no.

 

[Portage_Bay]

FatBear,

I too come from a work boat background where hydraulics are a given. I wish it were so on 40' pleasure boats but it isn't.

Regarding how fast things could go wrong stepping off. We had a situation last fall with wind at about 15 kts on the beam, same side we were tied to. The boat needed to be moved to another slip. We were both on the dock turning lines loose, all but the mid-ship breast line. The plan was I would turn the mid-ship breast line loose and step aboard all in one graceful well controlled move. She would walk to the new slip to catch lines. Nope. That didn't go so well. Nearly instantly the boat was blown to the next finger over, fortunately that slip was not occupied. It was a real life lesson for me that 33,000 lbs, 40' with a fly bridge and lots of canvas gets blown off quickly. Not at all like heavy displacement with a deep draft.

 

[Seevee]

FatBear,

I too come from a work boat background where hydraulics are a given. I wish it were so on 40' pleasure boats but it isn't.

Regarding how fast things could go wrong stepping off. We had a situation last fall with wind at about 15 kts on the beam, same side we were tied to. The boat needed to be moved to another slip. We were both on the dock turning lines loose, all but the mid-ship breast line. The plan was I would turn the mid-ship breast line loose and step aboard all in one graceful well controlled move. She would walk to the new slip to catch lines. Nope. That didn't go so well. Nearly instantly the boat was blown to the next finger over, fortunately that slip was not occupied. It was a real life lesson for me that 33,000 lbs, 40' with a fly bridge and lots of canvas gets blown off quickly. Not at all like heavy displacement with a deep draft.

Agreed, dangerous. There's a few good quick release knots for untying that last line fast. Like the tumble hitch or the mooring hitch, however get that tied BEFORE releasing other lines. Also, tie it TIGHT, so the boat will move little, especially in really strong current or high winds. Just pull the bitter end when ON the boat and motor out..... but can't be too slow. Works well with two people.


Believe me, I've been there and gets embarrasing, if not expensive if the boat goes where you don't want it to.

 

[FatBear]

You are NOT stepping off the boat before it's secured to the dock are you? If so, that's a HUGE no/no.

Depending on circumstances, yes.

I do understand the risks, but as I said, I have good situational awareness and also a bit of professional experience (a long time ago!) stepping across with lines. My method on the tugs was to do as I was told. I once almost had to spend the night on a barge in the middle of a bay in the middle of nowhere (the middle of the Aleutians is pretty much the middle of nowhere) during a storm with gusts well over 135MPH because the old tug was getting blown away. I had been sent over to catch a line they were going to toss to me. Even at full throttle the boat couldn't make headway against the gusts, which is pretty much the same as an uncrewed boat drifting away. I would not have survived the night. (It was also pretty cold.) I was told to jump for the boat and I jumped. I barely caught the gunnel near the bow and two other crewmembers caught me and pulled me in. Their eyes were really big. Mine probably were, too. I remember the bruises that healed pretty quickly in a 20 year old body and the relief at not dying or having to swim for the boat. I am 45 years older now and much wiser. No way I'm going to let some moron (barely more than a child, himself) tell me to risk my life like that.

My preferred method mooring the 28' boat alone was to put a line across by tossing a bight of line over a cleat (or flipping it onto the cleat when I miss) and making it back up on the boat. That is probably what I will do most of the time. But I want insurance. On the water, like in many things, if you only have or only know one way to do a thing, you will not be prepared to cope with the variety of situations that will be presented to you. So in some circumstances I will probably use the thrusters to hold the boat against the dock while I get a line or two onto a cleat, in other circumstances I will step across with the line or throw it first.

One example of such a situation might be the kind of dock that has horizontal 4x4s along the edge rather than cleats. There are a lot of those in Oregon. The 4x4s are spaced up off the dock level on short 2x4 or 4x4 spacers. You can't toss a line over a cleat or bollard, you have to actually fish the line under and wrap it around the 4x4. The idea is partly that there is a perfect cleat spacing for any boat, but I think mostly because it's cheaper than putting on a bunch of cleats. Someone has to be on the dock to do a tie-up like this and I will be that someone if we run into a dock with this setup. I'm willing to spend a bunch of money to make sure the boat stays against the dock while I am doing it. When you think ahead and prepare things are far more likely to go well. But there are no sure things. To believe so is hubris.

 

[Seevee]

FatBear,


We can agree to disagree, but I can hardly think of a situation where a pleasure boater needs to jump off prior to securing the boat. I can throw a line around a 4x4, I'd be you can too, and can always use a hook.


Even with no cleats, no pilings there's always my portable dock cleats, but have always been able to secure at least on prior to getting off.


There's "might be" a situation where you jump off first, but would be with zero wind/current.


And your example with 135 kt winds "might be" that situation..... however, I'd bet that we don't see that very often.

 

[FatBear]

I can throw a line around a 4x4, I'd be you can too, and can always use a hook.

A horizontal 4x4 that is spaced an inch and a half or three and a half inches off of the dock? (I'll put a photo below.) Of course I can throw a line around a vertical 4x4. I will be in total awe of anyone who can throw a line around the type I am talking about. And I have thrown lines from 3/8" heaving lines up to 7" towing hawsers (for very short distances!) and around little cleats, big cleats, bollards, bitts, ship's railings, etc.

Even with no cleats, no pilings there's always my portable dock cleats, but have always been able to secure at least on prior to getting off.

See: now you've introduced something interesting. What is a portable docking cleat? How does it work from the boat? I see the picture. It looks like something you would slip down between two planks. (Better not get any big wakes or you'll pull up planks.) It does look very handy, but I don't see how you would insert it without getting off of the boat.

There's "might be" a situation where you jump off first, but would be with zero wind/current.

You are fixating on something that is unimportant. I was lazy about how I wrote the part about getting off of the boat because I wasn't asking for docking advice. That might come in the future (my ego does actually still fit inside of my head) but for now I was asking about a certain functionality with bow thrusters.

I lived for 10 years right next (8 feet away) from a yacht club dock where large boats came and went all of the time. It is amazing how few big boat operators know anything about mooring. I'd say less than 10% are really good at it. One thing that almost nobody understands is where the control of the lines should be. If you are mooring a boat, you should retain control of the lines on the boat. Don't cleat them off on the dock, cleat them off on the boat. If you are towing, pass the eye to the boat that is under tow and cleat it off to the boat that is doing the towing. (Unless you are on the boat being towed and you think the operator of the towing boat is a moron. In that case you will want to keep control for yourself!)

Most people have mooring lines which are less than half the length that they should have. Or if they have long ones, they don't know how to use them to their best advantage. If you have a mooring line that is three times as long as the length where it will typically be used, you can keep an eye around a cleat on your boat, make a bight from the line, and when you get close enough you can throw it towards a cleat or bollard on a dock or other boat. If it misses going around it will still usually lay close to the cleat or bollard and then you give one side of the bight a flip and it will go over. Now you have a line that goes out, around, and back to your boat where you can cleat it off. You don't have to do this doubling with every line (though it is a good idea in nasty weather) but mostly just when coming alongside. Maybe with a spring line, maybe just with a breast line as circumstances dictate. As I mentioned before, this would be my preferred method. But I want the thrusters to be my second pair of hands because things just don't always go well. Insurance. It's good for the boat and good for the marriage.

And your example with 135 kt winds "might be" that situation..... however, I'd bet that we don't see that very often.

Depends on where you are. But I don't ever want to live anyplace like that again! Or maybe I should say not at my age - though I wish I were still young enough to take on such adventures.

Here is a picture I found that sort of illustrates the horizontal 4x4 tie-ups. I've actually seen this same arrangement on many ship's docks, but with 12x12s instead of 4x4s. On those big docks they are really used just for edging, so vehicles don't roll off into the water and such. There are cleats or bollards on the dock for mooring. But in Oregon they are used for actual tie-ups on small docks for pleasure craft. You have to wrap your mooring line around the horizontal 4x4s. There isn't anywhere else to tie up. And if there is nobody else to help you, you have to get out on the dock and do it yourself. Before you've tied up to anything. I haven't seen them down here in southern CA, but I have seen them on the Sacramento.

 

[FatBear]

Even with no cleats, no pilings there's always my portable dock cleats

I searched out that portable cleat. It may not work all of the time, but looks like the kind of thing which will someday be the only thing that works. More insurance.


Thanks for the hint.

 

[Lepke]

The bad part about using hydraulics is you have to run lines to and from the thruster and you need a engine driven pump & tank. So it's a little more trouble to install.

The good part is hydraulic systems run for many years without any issue and require little maintenance. Usually the pump is controlled by a clutch, so the system only runs when you need your thrusters. And if you need a more powerful windless, you can have a hydraulic driven one or maybe a tuna puller.

 

[lwarden]

My Lindell is an oddity for a smaller recreational boat as it is all hydraulic. Bow thruster, windlass, pot puller are all run from a PTO on the port transmission. This also runs jog lever controls for the flybridge and cockpit controls (salon control is a wheel). The hydraulic thruster is quieter than electric and as stated can run indefinitely. No problem with the hydraulic system so far, it seems pretty reliable and some could argue running hydraulic lines is no worse than running large gauge wire to something like a bow thruster.
The downside is the pump. If you have it on a single main then I suppose you are SOL if you lose your main, the bow thruster is no good anyway. But on a twin if you are unlucky enough to lose the engine with the PTO then that bow thruster isn't going to do any good docking on the one remaining engine, call Seatow I suspect. I don't like the idea of having to run the genny to power an electronic pump. I did see a Lindell with PTO's on both engines, but that seemed overkill.

Regarding the handling question: With our cockpit controls and easy egress from the cockpit single handling is pretty simple to do and docking is no issue if all the lines are prepared. I can reach over the rail and tie the stern to a cleat, power forward if needed and get the bow in and step off to secure it. The key is more about how easy it is to get on and off the boat and to and from the controls.

When we were in Cap Sante marina in Anacortes I watched a guy single hand in a Maritomo 50 with a remote control box. Apparently he does it all the time.

 

[Rossland]

Look at https://sideshift.com

They have a remote control. My ABT Trac thrusters do not have remote controls. I wish they did.

 

[porman]

FatBear, those are called bullrails. They are common in the PNW, especially in Canada and my wife hates them.

 

[FatBear]

FatBear, those are called bullrails. They are common in the PNW, especially in Canada and my wife hates them.

Thanks. Bullrails. I'll have to remember that. They are so mundane that I've never heard them named, even though I've been tripping over them and chaffing lines on them for decades.

 

[Seevee]

I searched out that portable cleat. It may not work all of the time, but looks like the kind of thing which will someday be the only thing that works. More insurance.


Thanks for the hint.

FatBear,


You're welcome.
And, totally agree with you on the bull rails... hard to tie to. In some cases with rather calm waters I can reach over and hook my portable cleat on something to secure the boat first... same with the bull rail. But doesn't always work, so that's a case where you must get off.



Just don't want to do when my GF is pissed off at me, cuz she'll bail out and leave me there.

 

[OldDan1943]

Take a gander at DockMate.
Wireless
Take control/relinquish control
Bow thruster
Stern thruster
Horn
Engine control, at idle, momentary fwd or aft.
Anchor up/down (optional)
(No rudder control)


I just had one installed on my boat and still trying to sort things out. Learning curve.
They make them for single and double engines etc
The system does not automatically hold the boat against the dock. You gotta control it.
One caution, watch your battery voltage.

 

[ghost]

Take a gander at DockMate.
Wireless
Take control/relinquish control
Bow thruster
Stern thruster
Horn
Engine control, at idle, momentary fwd or aft.
Anchor up/down (optional)
(No rudder control)


I just had one installed on my boat and still trying to sort things out. Learning curve.
They make them for single and double engines etc
The system does not automatically hold the boat against the dock. You gotta control it.
One caution, watch your battery voltage.

How much did the dockmate cost you? I just put in glendinning and went with a wired remote in my cockpit. Ran out of coin for considering full wireless, maybe next year.

 

[OldDan1943]

How much did the dockmate cost you? I just put in glendinning and went with a wired remote in my cockpit. Ran out of coin for considering full wireless, maybe next year.

That depends on 1 or 2 engines, thrusters ON/OFF or variable speed etc.

Mine was about $8K, well worth it if you do single handing. I do not have the wireless control for the anchor.

Was funny, when the two techs came onboard, they told me go sit down, out of the way. At least they were kind about it. LOL

 

[Seevee]

FatBear,


(my comments only pertain to electric thrusters, which only operate intermittently)


Getting back to your original question.....

I could argue that thrusters are your second choice for maneuvering. Engine(s) and spring lines would be your first. Holding a boat to a dock with thrusters will not work the way you're intending. If you can get that close, put a spring line on and hold the boat with it.... MUCH safer. And with a single spring and the engine holding the boat to the dock, you could get off to secure the other lines (however, I want at least TWO springs on before considering leaving the boat).

Thrusters add a little bit of extra positioning.. push the bow/stern to a better advantage, perhaps to help turn in a slip area, to help swing back a bow are stern that's getting pushed out or to align with pilings.

I could argue STRONGLY to get your wife involved in operating the boat... even if just a little bit. Get he up to speed to a least be able to control the shift while you adjust the spring. Or get the boat those last few feet in while you throw the line over a cleat/piling. You could have the remote thruster control with you to tweak things. If she doesn't get involved, you have TWO choices. 1. Operate the boat solo, or 2. Get a GF that will help.

However, yes thrusters are a HUGE help, especially with a single. My previous 3 boats had them. My last boat (single engine 400 Mainship) and my current boat (twin 430 Mainship) have thrusters on both ends. Now, in either case, you can operate fine without, but with they offer a lot of help. BUT they will not dock the boat for you.... only help position it.

And I can (and do) operate them single handed without a problem, however I've never locked single handed. But there's LOTS of captains that do, many on this thread.

Now, a bit depends on your mission. If you plan to go from marina to marina, the thrusters will come in more handy. If you anchor out all the time, probably not. I could argue to shop for a boat that has at lease a bow thruster (single or twins). That would give you a lot of options/control.

 

[OldDan1943]

IF you have electric thrusters, keep an eye on your battery voltage. The Cummins 380 QSB shuts down when voltage is about 10.6vts. That is why I moved my bow thruster to the house batteries. Now I have both the bow and stern thruster on the 3X4D house batteries. Gotta keep the Cummins running.

 

[Seevee]

IF you have electric thrusters, keep an eye on your battery voltage. The Cummins 380 QSB shuts down when voltage is about 10.6vts. That is why I moved my bow thruster to the house batteries. Now I have both the bow and stern thruster on the 3X4D house batteries. Gotta keep the Cummins running.

Excellent point, and I do the same. When I use the bow thruster aggressively, the voltage will get down in the 10 range, but only for a few seconds. Fortunately my Yanmars do not shut down. But questions for you: Why would the Cummins shut down... what is electric on them that would do this?


Now, my stern thrusters have their own batteries.