Bow and / or Stern Thrusters?
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RT Firefly
Enigma
Greetings,
Mr. T. "Hasn't this been covered dozens of times here?" And your point is....?
Mr. T. "Hasn't this been covered dozens of times here?" And your point is....?
cappy208
Guru
Although my experience with nozzles is in the commercial world, it applies to all sizes.
Open wheels twist great. Open wheels allow you to have confidence in 'repeatability' of walk effect when backing (single or twin). Open wheels allow hard over rudder when maneuvering.
Nozzles allow VERY limited walk effect. (Not none, but little). Nozzles can have rudder stall when maneuvering. (If you leave the rudder over full it starves the prop of water shake shake shake). Nozzles greatly enhance ahead steering and vector change.
There are actually two types of nozzles made. One for primarily ahead thrust. (Tugs use these for long distance towing). And the other about equal ahead and back (but not as good at ahead as the first type).
Lepke
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I have twins now and have been running boats and ships for more than 60 years. Mostly twin screw and never with a thruster. I probably have a tainted view. I don't find twins prohibitively expensive so have always owned twins in private boats of size. My current boat is 83' x 17' and never failed to go where I want to put it. But I plan my dockings and avoid high winds. Even though long and narrow, it seems to twist fine and the stern walks sideways easily. I don't remember being above idle when docking except for rotating on center.
People I know with thrusters seem to have a high level of equipment failures. And then they're lost on docking. In my tainted opinion, it's cheaper and easier to learn boat handling.
People I know with thrusters seem to have a high level of equipment failures. And then they're lost on docking. In my tainted opinion, it's cheaper and easier to learn boat handling.
markpierce
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Just think. ... Single-engine boaters were made to feel ashamed of having a thruster. Often, the accusations came from those with twin engines! Now, those with twin engines want both bow and stern thrusters. More power to them. (That's what cruise ships have.)
Always use my thruster, if not only to test it is still working or to angle the boat backing out of the berth to counter-act propeller walk.
Always use my thruster, if not only to test it is still working or to angle the boat backing out of the berth to counter-act propeller walk.
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Comodave
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It is not so much about not knowing how to handle the boat or even being able to do so. I have been boating for over 50 years and am a qualified Coxswain in the CG Auxiliary also a Qualifications Examiner. I know how to handle a boat and am certainly able to do so. It is about quality of boating life. As we get older it is not as easy to pull the lines when docking or push the boat around. If having thrusters will enable us to boat 5 or 10 years longer than we could otherwise, then I will have thrusters. I am actually installing a stern thruster at this time. All that is left to do is hook up the wiring and install the battery. I would like a bow thruster, but in order to put in a tunnel I would have to relocate our main water tank. So in the future I may put a pod bow thruster in. Having a stern thruster will help when docking since my wife and I are usually alone on the boat she takes the bow and I handle the helm and the stern. We have a Lab that has to be in the way at all times. When we dock or lock through I can get the bow and stern where I want them without a problem usually. The problem is the time it takes me to get from the flybridge down to the sundeck and past the dog in order to pass the stern line. By the time I get to the stern line the boat has started to drift away from the dock or lock wall. With the stern thruster and remote control I will be able to bring it back to the dock without breaking my neck by hurrying so much. I find that when I am hurrying is when I tend to get hurt and or make mistakes. So to all the people that say just learn how to handle the boat, that isn't the problem. The time to get the lines secured before the boat blows away from the dock is the problem. That is where the stern thruster will shine.
dhmeissner
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Thanks Comodave, great post.
dhmeissner
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Nightsky
Senior Member
If I had one, would I even be posting?We could at least try to put new spins on these old discussions. Ok... Maybe THAT was my point.
The OP did put a new spin on it, he included a poll!
cappy208
Guru
Bob Cofer
Guru
cappy208
Guru
This is what is appended on my Stem. https://sideshift.com/bow-thrusters/
It's not pretty. But on the upside it has NO holes below the waterline, is easily installed and (counting the days) easily removed. Actually has been helpful in some situations. But I generally don't need or use it. It's a novelty in use.
This is what it looks like on the boat
Would I buy one? No. Would I replace this if it failed? No. But it came with the boat.
It's not pretty. But on the upside it has NO holes below the waterline, is easily installed and (counting the days) easily removed. Actually has been helpful in some situations. But I generally don't need or use it. It's a novelty in use.
This is what it looks like on the boat
Would I buy one? No. Would I replace this if it failed? No. But it came with the boat.
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Capt.Bill11
Guru
They need to post a video that shows how well the work with a strong wind and/or current.
A paddle will move you around on a calm day.
If you look closely, it looks like the frame speed was sped up to make it look like the boat is moving away from the dock faster than it really is.
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markpierce
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Exercising the thruster:
Click on it!
Click on it!
dhmeissner
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Always love your pix & videos Mark
RT Firefly
Enigma
Greetings,
Mr. mp. great video and boat handling BUT you need a sound track. May I suggest this particular piece...
Mr. mp. great video and boat handling BUT you need a sound track. May I suggest this particular piece...
johnma
Guru
Richard,
What kind of problem are you having? With hydraulics you can always tell where the issue is by checking which component gets hot first: pump, hyd motor, valve. While you're at the dock have someone operate the thruster while you do "touch tests" on each component.
If it is an intermittent issue that happens whether hot or cold it is probably a control issue that will often be a lose wire or bad connection. If you're pump is running other systems such as a windlass and that works fine you can rule out the pump.
John
What kind of problem are you having? With hydraulics you can always tell where the issue is by checking which component gets hot first: pump, hyd motor, valve. While you're at the dock have someone operate the thruster while you do "touch tests" on each component.
If it is an intermittent issue that happens whether hot or cold it is probably a control issue that will often be a lose wire or bad connection. If you're pump is running other systems such as a windlass and that works fine you can rule out the pump.
John
Drake
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Exactly what I do.
Our boat came with bow thruster and we added a stern thruster a couple of years later. I'm glad we did (although I'm really unhappy with our installer). I rarely use either of them, but when they're handy, they're very handy.
Britannia
Wannabe
John,
The bow thruster runs fine for a while when the engine is first started. Say 10-15 minutes. After that the power drops off significantly. My fin stabilizers are run from the same pump and seem to operate fine all the time. I'm suspecting that it's a problem with the directional valve but don't have proof.
Richard
Bigsfish
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My current boat has pods but a previous boat had a thruster. I always thought of the thruster like insurance: it there and you hope it's not needed but when it is your happy to have it.
johnma
Guru
Richard
ok so it"s not a pump problem. That narrows it down to a motor or valve. Since valves generally either work or don't work regardless of temperature I would take a hard look at the motor first. When hydraulic fluid goes from high pressure to low pressure without doing work (an internal leak or bypass) it creates heat. Hold your hand on the motor while someone operates the thruster. If it gets unusually hot, say 150-160 degrees F in 10 seconds or so you have a bad motor that need to be rebuilt or replaced. If it does not get hot the fluid is bypassing before it reaches the motor and that leaves only the valve itself or the solenoid. With a multimeter take a resistance reading through the coil (ohm setting on your meter) if you have zero resistance its a bad coil or you could have a loose ground connection that breaks when the coil gets hot. If that checks out take a look at the tag number on the valve. If its the same as the valve for your stabilizer swap them and see if the problem moves to your stabilizer. If you have cartridge valves (valves that screw into an aluminum or steel manifold) the part number is stamped on the wrench flats. these are very inexpensive and you can buy them at any hydraulic equipment distributor. If it says "Sun" on the valve they must be purchased from a Sun dealer. All of the other brands are physically interchangeable with each other.
John
ok so it"s not a pump problem. That narrows it down to a motor or valve. Since valves generally either work or don't work regardless of temperature I would take a hard look at the motor first. When hydraulic fluid goes from high pressure to low pressure without doing work (an internal leak or bypass) it creates heat. Hold your hand on the motor while someone operates the thruster. If it gets unusually hot, say 150-160 degrees F in 10 seconds or so you have a bad motor that need to be rebuilt or replaced. If it does not get hot the fluid is bypassing before it reaches the motor and that leaves only the valve itself or the solenoid. With a multimeter take a resistance reading through the coil (ohm setting on your meter) if you have zero resistance its a bad coil or you could have a loose ground connection that breaks when the coil gets hot. If that checks out take a look at the tag number on the valve. If its the same as the valve for your stabilizer swap them and see if the problem moves to your stabilizer. If you have cartridge valves (valves that screw into an aluminum or steel manifold) the part number is stamped on the wrench flats. these are very inexpensive and you can buy them at any hydraulic equipment distributor. If it says "Sun" on the valve they must be purchased from a Sun dealer. All of the other brands are physically interchangeable with each other.
John
MurrayM
Guru
Great point.
Right now Badger has a single engine and no thrusters, but we'll add them when age creeps up on us.
We dock bow first and have to make a hard turn against prop walk when going astern leaving our berth, but with a bit of speed our big rudder easily does the job, even against a stiff wind. So far, while entering the berth, prop walk and the occasional burst of power against the rudder (one way or the other) does the trick. Must be doing something right...haven't had to retreat with my tail between the legs and try again for a couple years.
AusCan
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After my first singlehanded attempt at docking with my new single engined full keeled boat, a bow thruster was on the top of my ToDo list. Since then I've rubbed and bumped the dock numerous times, although nothing that couldn't be "polished out". Over the past 3 years the thrusters have somehow disappeared off my ToDo list.
But - I've learned:
how to read the wind and current,
how to handle spring lines,
how to make prop walk work in your favour,
how to abandon the plan to dock where you originally planned to dock
But - I've learned:
how to read the wind and current,
how to handle spring lines,
how to make prop walk work in your favour,
how to abandon the plan to dock where you originally planned to dock
dhays
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I have an angled birth with an extremely narrow fairway behind me. Even on my 40' sailboat, backing out of the slip, turning against the prop-walk was extremely difficult with some wind/current conditions. Fortunately, I never hit anything but a couple of times I came close to needing to fend off. That was with a large rudder and a proper keel.
On the North Pacific, it would be impossible to do without at least a bow thruster in some wind conditions.
kev_rm
Senior Member
You forgot the poll option "Whenever I hear the shrieking of thrusters I immediately try to locate the cloud of smug floating above the captain using them".
