Bow Thruster vs Stern Thruster

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How much complication does one want in the way of engines and motors? Twin propulsion plants, a genset, a bow thruster, auto-pilot, and a stern thruster?

How about a Yacht Controller By the way all the mechanical complications pale in terms of wife complications if docking goes wrong... My goal is to make boating safe and fun not score points for my docking acumen...
 
Engine RPMs

Yesterday, my engine stalled while docking head on. About 8 ft away. I was solo and no dock hand, so crash!! The engine has a stern thruster that runs off the front pully. The thruster slowed the motor to a stall. To avoid another crash, I want to raise the RPMs to 700 or 750. I am now at 650. Looking for imput on this matter Archie Bricker
 
Bow thrusters are pretty common on new single screw boats. Stern thrusters, not so much unless the boat has both. There's probably a reason for this.


Both would be nice but given the choice of one or the other, I'll take the bow thruster.


I think for most of us, cutting two 8" diameter holes in our boat's hull, having them line up and making a permanent watertight seal is beyond our DIY capabilities. I suggest finding a company that specializes in bow thrusters and installation. They will know what is best for your boat and they won't be installing one for the first time.
 
Have a bow thruster only on my single-engine boat. Don't feel particularly handicapped without one on the stern. With judicious use, rudder and propeller can maneuver the stern, but less simply than a stern thruster.

How much complication does one want in the way of engines and motors? Twin propulsion plants, a genset, a bow thruster, auto-pilot, and a stern thruster?

That is great that you can handle your boat without need of a stern thruster. I can to, as long as I limit where I try to dock. I don't want to limit myself that much however. I am sure that if I was better at handling my boat, I would have no need of a stern, or bow thruster.

Here is a spot I wedged myself into on my last trip. Langley WA. This is roughly the configuration of boats that were there when I went in. The yellow arrow points to the slip that was open. I added the boats to the google image that were there when we arrived and left. I am not good enough to squeeze into that space without bow and stern thrusters. As it was, everyone there on the dock was very, very nervous when it became evident as to where I was headed. BTW, it wasn't my choice, but where the warfinger directed me as it was the only empty slip in the small harbor and I think I was as nervous as any of the onlookers.
 

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The charter captain I worked for always advised to never approach a dock faster than you are willing to hit it. Once day we came up the creek, turned hard to starboard to line up for reversing into our slip, when he shifted into reverse the prop said goodbye and we were powerless to avoid hitting the dock in front of us. I don't recall if the prop nut backed off or we snapped the shaft, I believe the shaft snapped just behind the cutlass bearing but there hadn't been the least bit of vibration. Fortunately most Chesapeake deadrises have huge rudders and he was able to avoid hitting any boats and just hit the dock itself. Really powerless feeling to ride 46' of boat headlong into a dock.
 
For years spring lines were the thrusters of today.

Does't make them better, but serviceable if you get familiar with them.

Does it make thing safer? Absolutely if trying to do things with a boat you and your crew otherwise couldnt.

Does the average boater need them to cruise or loop? Really debatable as there are some variables.
 
The charter captain I worked for always advised to never approach a dock faster than you are willing to hit it...........

That advice gets passed around a lot but you have to balance your speed with the ability to control the boat. Wind and/or current can get you and unlike parking a car at Walmart, you can't just stop and figure out what to do next.
 
The trouble with teaching "never" use more power than willing to hit the dock...is that breeds timidity when often a tad more power will keep you from hitting everything else in sight.

Often new boaters wind up hitting so many things that they give up, hard,y use their boats and eventually get out of boating from embarrasment.

If having trouble dock g longer than usual, professional instruction often pays big dividends.

If you use that argument about speed, the same argument can be used to avoid single engines in general and thrusters for docking.

Docking involves some risks. If the unavoidable happens, and the results might involve serious issues and the risks can't be managed....find a different dock or docking conditions.
 
That advice gets passed around a lot but you have to balance your speed with the ability to control the boat. Wind and/or current can get you and unlike parking a car at Walmart, you can't just stop and figure out what to do next.

I agree, you have no control at a standstill, it was just a funny example of how sometimes things are beyond your control. His advice was given in an environment of show boating (bad pun) where some charter captains are still reversing at 6-7 knots when the transom passes between the poles. I've heard of shift linkage failures sending 20 tons of boat backwards into a dock packed with onlookers waiting to see the day's catch (something I never experienced thankfully).
 
dhaves, I could dock there successfully but could not single-handedly extract my starboard-walk boat in that situation shown in #94. My shorter boat is less demanding.
 
That advice gets passed around a lot but you have to balance your speed with the ability to control the boat. Wind and/or current can get you and unlike parking a car at Walmart, you can't just stop and figure out what to do next.

One of the hardest things for me to adapt to with a trawler compared to my sailboat was this very thing. With the sailboat, I would generally ghost in and out of slips with very little speed and generally the engine was in neutral until the the very end when a second of reverse brought us to a stand still.

That doesn't work with my boat now. The rudder is small by comparison and there is no fin keel to pivot the boat around. I am slowly learning that I need to use the rudder and throttle to move the stern around in both forward and reverse. The sailboat was more like racing on an autocross course, the power boat is more like drifting. You have to apply power to get the rear end too move.
 
How much complication does one want in the way of engines and motors? Twin propulsion plants, a genset, a bow thruster, auto-pilot, and a stern thruster?

Look into the Volvo IPS dual pod steering system.

Want to do a figure 8 while keeping the same heading. No problem. Want to "hover" in place 6 inches from the dock (linked to GPS) in tricky wind and/or currents? Eezy-peezy.

Not for me, but about as accurate as you can get with no bow or stern thrusters.
 
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Yesterday, my engine stalled while docking head on. About 8 ft away. I was solo and no dock hand, so crash!! The engine has a stern thruster that runs off the front pully. The thruster slowed the motor to a stall. To avoid another crash, I want to raise the RPMs to 700 or 750. I am now at 650. Looking for imput on this matter Archie Bricker

just nudge the throttle up a bit. However most diesels have bumper springs in the IP to prevent stalling. It may be adjustable. What make and model engine?
 
I would like to have both bow and stern thrusters on our 41' boat. My reasoning is that even though I have been boating for 48 years and am pretty good at handling a boat we are getting older and not as agile or as strong. My wife broke her arm badly last year and had a shoulder replacement that did not work. She still has almost no strength and very little range of motion. We just got back from the east coast and in the process went through 73 locks. Thrusters would have made it much easier and less demanding on her arm. If we put thrusters on the boat and are able to extend our boating life by 7 to 8 years longer than we would be able to without thrusters, what is that worth??? I do not have room for an internal bow thruster due to water tanks under the forward cabin deck. I will be putting in a stern thruster since it is so easy to do. For the bow thruster, I am looking at the external pod thrusters that bolt onto the keel below the water. Does anyone have experience with them? Sidepower looks pretty good with their variable speed controller.
 
I would like to have both bow and stern thrusters on our 41' boat. My reasoning is that even though I have been boating for 48 years and am pretty good at handling a boat we are getting older and not as agile or as strong. My wife broke her arm badly last year and had a shoulder replacement that did not work. She still has almost no strength and very little range of motion. We just got back from the east coast and in the process went through 73 locks. Thrusters would have made it much easier and less demanding on her arm. If we put thrusters on the boat and are able to extend our boating life by 7 to 8 years longer than we would be able to without thrusters, what is that worth??? I do not have room for an internal bow thruster due to water tanks under the forward cabin deck. I will be putting in a stern thruster since it is so easy to do. For the bow thruster, I am looking at the external pod thrusters that bolt onto the keel below the water. Does anyone have experience with them? Sidepower looks pretty good with their variable speed controller.
:thumb::thumb::thumb:...absolutely...pleasure boating...whatever it takes.:D
 
The charter captain I worked for always advised to never approach a dock faster than you are willing to hit it.

While I am in full agreement with this concept, I have been in a number of situations where the cross winds, or following winds were such that speed / power was necessary to keep control of the boat.
 
I would like to have both bow and stern thrusters on our 41' boat. My reasoning is that even though I have been boating for 48 years and am pretty good at handling a boat we are getting older and not as agile or as strong. My wife broke her arm badly last year and had a shoulder replacement that did not work. She still has almost no strength and very little range of motion. We just got back from the east coast and in the process went through 73 locks. Thrusters would have made it much easier and less demanding on her arm. If we put thrusters on the boat and are able to extend our boating life by 7 to 8 years longer than we would be able to without thrusters, what is that worth??? I do not chave room for an internal bow thruster due to water tanks under the forward cabin deck. I will be putting in a stern thruster since it is so easy to do. For the bow thruster, I am looking at the external pod thrusters that bolt onto the keel below the water. Does anyone have experience with them? Sidepower looks pretty good with their variable speed controller.

Comodave has stated my thoughts better than I could have. Fortunately we have single main w sidepower thrusters both ends. Our MShip has little prop walk due to tunnel and also a small rudder.
I get lots of grief but it's mostly jealousy...IMHO
why not make boating easy and fun???? If the Admiral is happy so is the Capt.
 
Hard lock port or starb and put in fwd gear gets dramatic changes in direction at the pointy end but not much happens when I do the same in reverse with mine due to, I suspect, a nozzle.

Stern thruster would be my choice for my boat as I would like to be able to shunt the bum across a few feet at times coming into a berth.
 
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That doesn't work with my boat now. The rudder is small by comparison

That is the key.

The PO of my 43' ocean alexander showed me how to man handle a small rudder if you will...

The PO would literally floor it in forward to get it to turn, and then floor it in reverse to get the boat to stop moving altogether. He repeated the forward hammer followed by the reverse hammer until the boat turned to exactly where he wanted it.

He looked at me cringing and said kid, you gotta treat it like your bitch. I was 58. :D
 
Thrusters allow one to go easy on their propulsion engines' transmissions.
 
Look into the Volvo IPS dual pod steering system.

Want to do a figure 8 while keeping the same heading. No problem. Want to "hover" in place 6 inches from the dock (linked to GPS) in tricky wind and/or currents? Eezy-peezy.

Not for me, but about as accurate as you can get with no bow or stern thrusters.

Crazy cool & crazy expensive;

 
Isn't the running gear vulnerable, as in protrudng and unprotected?
 
The prop in that picture is protected on bottom, but not either side. IPS has a skeg like an outboard.
 
The prop in that picture is protected on bottom, but not either side. IPS has a skeg like an outboard.

I am fascinated by the idea of both Volvo's IPS and the Cummins Zeus drives. Before we ordered our American Tug, we looked at the Sabre lineup as we really like the experience we had at Sabre when we purchased our sailboat from them 11 years ago. The word from "inside" is that Sabre is moving toward Volvo as the drivetrain of choice these days. When asked about the physical exposure of the drives and those forward facing propellers they claim to know of few "incidents". Not "no incidents" but not many...
We met a Sabre owner who knocked a Zeus drive off on a sandbar once. Insurance replaced the drive...

Everyone who has handled a Zeus or IPS loves the handling and maneuverability of the system. Even in Maine, the lobster pot haven of the world, people love them. They just both look so exposed to my eye, especially the IPS system!
In the end, we chose a very different boat design so we will simply have to observe these from a distance.
 

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Isn't the running gear vulnerable, as in protrudng and unprotected?

You mean like on most boats?

NOT like most boats...IPS Has a skeg BEHIND the props... NO PROTECTION FWD
The owner of this sweet Tiara has changed props twice now due to logs.
IMHO IPS type drives are more vulnerable...higher efficiency comes at a price.

The good news is this one stalled the engine but didn't affect shafts - only props which amazingly were repaired and looked like new.
 

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NOT like most boats...IPS Has a skeg BEHIND the props... NO PROTECTION FWD
The owner of this sweet Tiara has changed props twice now due to logs.
IMHO IPS type drives are more vulnerable...higher efficiency comes at a price.

The good news is this one stalled the engine but didn't affect shafts - only props which amazingly were repaired and looked like new.

Nothing like a picture to solidify my suspicions! That is simply amazing.
I'd love to know what happens when you snag a pot warp with those wheels too. Got any pictures of that?

Another question I have is what happens to steering if you disable one of the drives? I believe these boats steer by some kind of force vectoring of the drives or do the drives actually pivot?

Curious,
Bruce
 
They drive normal at lo or hi speed...you have to engage the computer & joy stick at lo speed and you then control direction and thrust w the joy stick.
The drives rotate but less than you might guess...I forget the exact # but memory says it's around +\- 30* and they can reverse...pretty cool to run but I don't think I'd invest in them. I can do almost the same maneuvers w single main and 2 thrusters...I just have to be cautious to not over do the thruster use
 
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