Steering a single

[restless]

What is proper procedure to navigate with single screw? I have bow thruster, but only about 10 sec and breaker trips ! I just want to know of any tricks other than slow is my friend!!

 

[Britannia]

My bow thruster is having problems too! I may be out next weekend without the use of it.

For maneuvering a significant technique is the "back and fill". It's how you turn a single screw boat in not much more than its own length without thrusters. Pick a direction to turn - a single screw boat will turn faster in one direction than the other. A right hand screw turns faster to starboard and a left hand screw to port. My boat is left hand screw.

Get the boat stopped. Apply full left rudder (in my case). Engage forward and give a quick, fairly powerful burst of the throttle. Immediately return to idle, then to neutral and then to reverse (without jamming the transmission too quickly). Now apply another burst of throttle in reverse to stop any forward way that you created - you can even give the boat a little sternway. At this point your boat should be swinging to the left. The forward blast caused prop wash off the rudder to turn the boat left. The reverse blast killed any way but the rudder had no effect on the turn.

Repeat this sequence, attempting to keep the boat from creeping too far forward or back. It shouldn't be long before you have completed a full 180 degree turn.

This is generally a good way to position a single screw boat. Use the rudder and forward to turn the boat (a bit like a stern thruster) and reverse to kill any forward way.

If your boat is heavy, full keeled and doesn't react to the rudder well at low speeds, you will end up steering the boat using idle speed, full rudder, and shifting in and out of gear. Every time you shift into forwards the boat will turn. Back into neutral and she'll straighten up.

There are many more techniques - but these are two common ones.

Richard

 

[Delta_JimS]

The best advice I can offer is to find a fairly large lagoon with no wind and flat water and practice, practice, practice. Experience your prop walk. Steer in circles backwards. Practice the boats behavior with short burst on the throttle with the wheel full, alternately, to each side, giving 10 sec. between bursts; then practice some more.
Diesel is cheap right now.

 

[hollywood8118]

What is proper procedure to navigate with single screw? I have bow thruster, but only about 10 sec and breaker trips ! I just want to know of any tricks other than slow is my friend!!

1- GET THE BOW THRUSTER FIXED!!

2- Follow Britannia's suggestions, great write up.


seriously, it the thermal limiter or breaker trips in 10 seconds something is wrong.. or you are the worlds worst judge of time ( highly unlikely).

A single with a thruster is great ( don't listen to the naysayers that think you need twins).

Happy Boating
HOLLYWOOD

 

[restless]

Thank you all, I will practice and hope to regain my confidence!!

 

[Steve]

Like previous post meniton, read up on and practice "back and fill", and how to take advantage of "prop walk", it's your friend! Check out the use of spring lines they can be a big help too.

 

[Captain K]

Ditto the spring lines advice. Spring lines are the poor man's bow thruster. Ask any sailor.

 

[ranger58sb]

Yep, we use spring lines routinely, even with twin engines. And sometimes even when not necessary, to give the crew practice.

Major areas for understanding and practice: planning and communications (Plan A, B, C, as many as necessary), back-and-fill, prop walk, reversing in a straight line, spring lines, and after-action analysis and discussion (every time).

And practice. I mean, right away, even after successful docking. Leave the slip, and do it again. Or pick a nice day, depart and return four or five times. Gradually begin to do that even on imperfect days. Build muscle memory, sharpen your sensory skills relative to tide, current, wind, etc.

And enjoy appropriate beverages, after successfully docking.

FWIW, aside from the additional issues (and benefits) with prop walk, all of that applies to twins as well.

-Chris

 

[Larry M]

The best advice I can offer is to find a fairly large lagoon with no wind and flat water and practice, practice, practice. Experience your prop walk. Steer in circles backwards. Practice the boats behavior with short burst on the throttle with the wheel full, alternately, to each side, giving 10 sec. between bursts; then practice some more.
Diesel is cheap right now.

Plus anchor a float/buoy and practice coming along side. (Just don't get it fouled in the prop). It's a good way to get use to distance perception from the helm without hitting a fixed object if you get to close.

 

[Old deckhand]

If you have some distance to back down learn to let the rudder catch. Each boat has individual characteristics and it just takes time to learn them. There are books and videos available on this topic.

 

[Nomad Willy]

Brit,
I too think your lesson on "back and fill" is excellent!
I do it every time I come back to my slip as I'm on the port side of the slip w a single screw boat and CC wheel backing in.
In the expression "back and fill" what does "fill" refer to?

I lean toward selecting the port side of the double slip because that gives the other tenant the easiest landing and approach so he's much less likely to tangle w my boat. This time I also selected a slip whereas the other boat is a narrow double end boat. Actually (for those that know them .. a Bristol Bay 32' fishboat). The owner just left for the fishing season in Alaska ... w/o his boat.

 

[BlueYonder]

Check your batteries. Once the voltage drops, amp draw will increase causing the breaker to trip.

 

[JDCAVE]

Check your batteries. Once the voltage drops, amp draw will increase causing the breaker to trip.

What he said. Wire size to the thruster may be a related issue, especially if it's 12 volt and the cable run is from the house batteries further aft. Our thruster is 24 volt and has a dedicated battery bank and charger, both of which are located forward. FWIW, I generally limit thruster use to 5 seconds or less.

Docking is still a learning process for me. I found this thread useful.

http://www.trawlerforum.com/forums/s3/docking-aha-moments-436.html


Jim
Sent from my iPad using Trawler Forum

 

[Heron]

Check your batteries. Once the voltage drops, amp draw will increase causing the breaker to trip.

What he said. Wire size to the thruster may be a related issue, especially if it's 12 volt and the cable run is from the house batteries further aft.

Agree...I have heard lots of stories of limited run times of Thrusters. I suspect either of the two above are the likely culprits. The cabling running to mine is about as big as my Thumb and I've never had it trip, no matter how long I ran it.

Long runs of #6/4/2 (typical for Battery wiring) Cable may not be afdequate

 

[QB]

Now apply another burst of throttle in reverse to stop any forward way that you created - you can even give the boat a little sternway. At this point your boat should be swinging to the left. The forward blast caused prop wash off the rudder to turn the boat left. The reverse blast killed any way but the rudder had no effect on the turn.

The burst in reverse is not just killing forward way, it is actually helping the turn to port because of starboard stern propwalk. This is what makes tight turns to port easier than starboard turns (in your single-screw boat with a left-hand prop).

To the OP: practice both, to see the difference.

 

[Carolena]

One other thing to check on the thruster is the brushes. Last year ours started acting up intermitently. Sometimes it would slow down and or trip the breaker, similar to a low voltage situation. I took out the brushes, which looked fine, cleaned up the dust and reinstalled them. This year we've had no problems (knock on wood).

 

[Codger2]

The burst in reverse is not just killing forward way, it is actually helping the turn to port because of starboard stern propwalk. This is what makes tight turns to port easier than starboard turns (in your single-screw boat with a left-hand prop).

Excellent post! Short, accurate & not confusing.

 

[Wxx3]

Britannia is right on

Back and fill
I try NOT to use bow thruster bc in my limited experience, when I really need it, it's not enough.

 

[Marin]

In maneuvering any boat, single or twin, prop walk and inertia are your friends once you learn how to take advantage of them.

 

[Britannia]

The burst in reverse is not just killing forward way, it is actually helping the turn to port because of starboard stern propwalk. This is what makes tight turns to port easier than starboard turns (in your single-screw boat with a left-hand prop).

To the OP: practice both, to see the difference.

Indeed it does. I didn't mention the whole prop-walk thing since I had already written enough! As others have mentioned, most single screw boats will not back in a straight line - at least not until you can get enough way for the rudder to bite. A LH screw will back to starboard and a RH screw to port. This can be used to your advantage once you learn what your boat does. As QB mentions, this means your back and fill is easier in one direction. You can still turn the other way though - it just takes more time.

Richard

 

[restless]

Thanks for all the good info, I talked to the lewmar tech and he said my 150 breaker was toooo small to replace with 250. So I did thruster has not failed, I am staying to the 15 to 20 sec burst which seems good!! Hanks again to all

 

[Britannia]

Great to hear you're back in business. I think I may have solved my bow thruster problem for now - at the expense of having the low power setting - which I don't really use anyway. With hydraulic thrusters you can run them all day long - no overheating.

Still practice those maneuvers though. Your engine is way more powerful than your thruster and will still help you get the bow into the wind when the thruster won't.

Richard

 

[Baker]

Thanks for all the good info, I talked to the lewmar tech and he said my 150 breaker was toooo small to replace with 250. So I did thruster has not failed, I am staying to the 15 to 20 sec burst which seems good!! Hanks again to all

With all due respect, 15-20 seconds on the thruster is relying on it too much....strictly my opinion. You should get to the point where the thruster is only needed for very short bursts. If you need it for more than that, you need to more practice.

 

[Northern Spy]

With all due respect, 15-20 seconds on the thruster is relying on it too much....strictly my opinion. You should get to the point where the thruster is only needed for very short bursts. If you need it for more than that, you need to more practice.

Or it could be undersized. 15-20 would spin my boat 360°.

 

[LarryM]

Or it could be undersized. 15-20 would spin my boat 360°.

Same here

 

[Britannia]

Or it could be undersized. 15-20 would spin my boat 360°.

Probably about 120° for mine...

 

[QB]

As others have mentioned, most single screw boats will not back in a straight line - at least not until you can get enough way for the rudder to bite.

Britannia, I'm not trying to pick on you! But the way you put that could be misleading.

Actually you can back a single-screw boat in a straight line as slow as you like, just not by only using reverse gear, and it's another maneuver well worth practicing.

 

[psneeld]

I would actually call any use of throttle and gears with even small rudder changes .... "maneuvering" in reverse.


Backing to me is putting an engine in reverse and only using rudder.


Either way...planning on going dead center right down the middle of a fairway in rearward motion is going to be challenging no matter.


Sure really good guys make it look easy...but it's not because the average boat is making it so.

 

[Britannia]

Britannia, I'm not trying to pick on you! But the way you put that could be misleading.

Actually you can back a single-screw boat in a straight line as slow as you like, just not by only using reverse gear, and it's another maneuver well worth practicing.

No problem - not feeling picked on. I try to use fewer words since I'm often accused of being too wordy!

Out of curiosity - what's your technique for backing up in straight line at speeds lower than that where the rudder starts to become effective? The only way I know is a short burst in reverse and then to neutral to let the boat's momentum take it in a straight line.

Richard

 

[Britannia]

...
Backing to me is putting an engine in reverse and only using rudder.
...

Yes - that's what I meant.