Spring Line and Bow Thruster Used in Combination

[Dockhead]

Complex harbor maneuvers are one of the scariest things I do in my boat. There is nothing which I encounter offshore on a regular basis which causes me to worry about being in control, but I regularly encounter situations in harbor maneuvers which are really challenging to me. When what you do in such situations works, it can be extremely satisfying. But I am often pushing the limits of my skill.

I have recently needed to use spring lines getting out of berths with the wind blowing me on. In one case, I was berthed on a ferry ramp in a kind of pocket with walls on both sides. The wind changed overnight pinning me directly on. And today I had to get off a quay with 20 knots of wind blowing me one – berthed closely between a pilot boat on one side, and a coast guard vessel (!) on the other. If you have some space and the wind is not blowing too hard, a spring line may not be needed at all – if you have a bow thruster. You can either thrust on to swing the stern out, or thrust off while motoring ahead with the wheel turned towards the quay, to move sideways off. But this doesn’t work with 20 knots of wind blowing you on.
In such cases I revert to the good old springing off method, usually rigging a bow line to swing the stern out while motoring ahead. What is good about this maneuver is that if the wind is beam-on, or if you’re lucky, behind the beam, then the boat becomes more and more stable as the stern starts to face into the wind. Then you can gently motor astern and release the spring.
However, I don’t like using contact between my boat and the quay as a pivot point. If the quay is high enough, I will hit the anchor and bend stuff, and a fender might be punctured. So I have been experimenting with using the bow thruster in combination with a spring line.
Results have been mixed so far. The three-way combination of forces is very complex. Thrusting out to keep the bow from contacting the quay tends to counteract the desired rotation out of the stern. I am finding that you have to let the bow get very close to the quay before using any bow thruster, and using it in the smallest doses possible, or the stern won’t swing out.


Another thing I’m experimenting with is going into reverse sooner – as soon as the stern is out somewhat. It seems possible to do this sooner than you might think, and that’s because the wind doesn’t affect the stern nearly as much as it does the bow, so the wind is already helping you once the stern is out a bit. Again it takes some nerve letting the bow get very close to the quay, but once you achieve an angle of more than 30 degrees or so, it seems to me that force in reverse will already make it possible to keep the bow clear of the quay.


Both of my recent maneuvers have been successful, but I think I am consuming more good luck than I would like to – I would like to have more control. I don't actually have all that much experience with this, compared to my general sailing experience -- I have only been sailing a boat this size -- too big to manhandle around in the harbor when things get complicated -- for eight years. Anyone go through this, and have any wise thoughts?

[Kenomac]

I can't really explain what I do when the time comes because every situation is different, but I don't hesitate to use the bow thruster in short bursts and ample use of fenders. Just make sure you never get yourself in a jam where you need to use the thruster too much, because it will trip the thermal shut down, then you'll have nothing for about a half hour until it resets.

Spring lines are really tough without onboard assistance. But one thing is for sure, I always prefer to put myself in a situation where I anticipate backing out instead of head out in forward. I just feel like I have more control not having to worry about the stern or davits hitting something. We're a center cockpit like you, so it's very easy to forget the stern.

One technique which has proven valuable is to be able to do a 360 pivot within one boat length using only the engine.

[UNCIVILIZED]

As a disclaimer, I've not driven much with bow thrusters, & was just taught to use the prop, rudder, & lines to control the boat. Anything from 5m to 200m. And it really, really pays to get some coaching on how to handle boats in close quarters, & in less than ideal conditions. Shorthanded/solo & otherwise. Since you get to see & then try a lot of things that you wouldn't perhaps think possible. Which later helps both confidence & planning a lot. For you, & for the crew.

When it comes right down to it, the ass end of the boat IS the one where the primary controls, prop & rudder, are, so it's the one to figure in advance you'll have the best control over. Which, assuming a non full keel, makes it the end of the boat which is easiest to lead with. And that if you blow an approach or docking situation while powering towards it in reverse, it tends to be easier to escape/power out of it simply by shifting the throttle, & driving forward. Including sometimes with a need to shift the rudder at a certain point, to kick the stern out, or regain control of the bow.

Know too that spring lines can be; adjusted, or cast off, entirely from the cockpit/helm station, or within a step or so from it. It's all in how you rig them. With long, double ended ones working best for solo/short-handed gigs.
Keep both ends of them where you (solo) can easily adjust them or cast them off, preferably with one end on a powerful, self tailing winch. And lead them to chocks or snatch blocks wherever you need to along the toerail from there.

The same can be done when you have crew onboard who are inexperienced. So that you either still fully control the lines, or are right next to a crewman to give commands, instead of having to shout up to the bow. And a big perk of having both ends of the line within easy reach, is that you can release them, & fully pull them up & out of the water, quickly, from back by the helm. That way there's little chance of them winding up in the prop.

Also, as important as planning the docking, or departure is. Having a couple of pre thought out escape plans is even more so. And it also helps a lot to have days which are dedicated only to docking practice, working up to stiffer & stiffer conditions over time.

Which it's worth organizing such with a few boats. So that you have 2x your normal crew compliment onboard, & take turns doing this with each boat. And if the other owners are up for it, try driving each others boats for said evolutions. It'll tune up your handling skills, & feel for different boat & control/control input configurations. Including having one boat be a trawler, or twin screw powerboat, & the other a high windage, single screw, sailboat.

This way, initially you have extra active hands onboard, & as things progress, the backup crew is still onboard, but only gets ordered into action if things are getting out of control. Thus you have backup, & also the learning curve isn't so steep as it would be with a smaller crew only, initially. Plus the perks of learnng to handle different boat types is obvious. The cross training, & little tricks which you learn & teach one another are invaluable. And often not one's you'd have thought of.


EDIT: It's also vital to have a standardized way for giving orders onboard, & what line handling terms mean, etc. As well as that the skipper is in charge, period, & not to be ignored or 2nd guessed. Such really slows down or kills the learning process, since folks can't fully focus on their jobs. And or a strong crew may be carrying a weak skipper so much that the skipper has an overinflated sense of his capabilities.

One other aspect to this is that once folks are mostly confident with the basics of handling the boat, have the training officer start introducing mock casualties. Such as telling the skipper that one of his 2 engines just shut down, or that it turns out that springline X isn't quite long enough, got dropped into the water, etc.

[Hobiehobie]

We were recently on a dock with very close vessels fore and aft with strong wind blowing us onto a dock with tall poles. Could not fathom a way to spring off without smacking the davits on the poles, or driving the bow into the ugly poles. So we just pulled ourselves out sideways with the dinghy fastened amidships! Obviously need a crew spare to do this but it was so much easier and controllable that trying to spring in very tight quarters.

A Dinghy with decent sized engine can be a very useful towboat.

[Dockhead]

Originally Posted by Hobiehobie

We were recently on a dock with very close vessels fore and aft with strong wind blowing us onto a dock with tall poles. Could not fathom a way to spring off without smacking the davits on the poles, or driving the bow into the ugly poles. So we just pulled ourselves out sideways with the dinghy fastened amidships! Obviously need a crew spare to do this but it was so much easier and controllable that trying to spring in very tight quarters.

A Dinghy with decent sized engine can be a very useful towboat.

Yes, a dinghy tug can be a great thing! I used to use my old wheel steered 25 horsepower dinghy for this from time to time when I had crew -- works fantastic. Haven't tried my new light dinghy with only 8 hp -- less than my bow thruster . I suspect it will be a lot less effective.

[Dockhead]

Originally Posted by UNCIVILIZED

As a disclaimer, I've not driven much with bow thrusters, & was just taught to use the prop, rudder, & lines to control the boat. Anything from 5m to 200m. And it really, really pays to get some coaching on how to handle boats in close quarters, & in less than ideal conditions. Shorthanded/solo & otherwise. Since you get to see & then try a lot of things that you wouldn't perhaps think possible. Which later helps both confidence & planning a lot. For you, & for the crew.

When it comes right down to it, the ass end of the boat IS the one where the primary controls, prop & rudder, are, so it's the one to figure in advance you'll have the best control over. Which, assuming a non full keel, makes it the end of the boat which is easiest to lead with. And that if you blow an approach or docking situation while powering towards it in reverse, it tends to be easier to escape/power out of it simply by shifting the throttle, & driving forward. Including sometimes with a need to shift the rudder at a certain point, to kick the stern out, or regain control of the bow.

Know too that spring lines can be; adjusted, or cast off, entirely from the cockpit/helm station, or within a step or so from it. It's all in how you rig them. With long, double ended ones working best for solo/short-handed gigs.
Keep both ends of them where you (solo) can easily adjust them or cast them off, preferably with one end on a powerful, self tailing winch. And lead them to chocks or snatch blocks wherever you need to along the toerail from there.

The same can be done when you have crew onboard who are inexperienced. So that you either still fully control the lines, or are right next to a crewman to give commands, instead of having to shout up to the bow. And a big perk of having both ends of the line within easy reach, is that you can release them, & fully pull them up & out of the water, quickly, from back by the helm. That way there's little chance of them winding up in the prop.

Also, as important as planning the docking, or departure is. Having a couple of pre thought out escape plans is even more so. And it also helps a lot to have days which are dedicated only to docking practice, working up to stiffer & stiffer conditions over time.

Which it's worth organizing such with a few boats. So that you have 2x your normal crew compliment onboard, & take turns doing this with each boat. And if the other owners are up for it, try driving each others boats for said evolutions. It'll tune up your handling skills, & feel for different boat & control/control input configurations. Including having one boat be a trawler, or twin screw powerboat, & the other a high windage, single screw, sailboat.

This way, initially you have extra active hands onboard, & as things progress, the backup crew is still onboard, but only gets ordered into action if things are getting out of control. Thus you have backup, & also the learning curve isn't so steep as it would be with a smaller crew only, initially. Plus the perks of learnng to handle different boat types is obvious. The cross training, & little tricks which you learn & teach one another are invaluable. And often not one's you'd have thought of.


EDIT: It's also vital to have a standardized way for giving orders onboard, & what line handling terms mean, etc. As well as that the skipper is in charge, period, & not to be ignored or 2nd guessed. Such really slows down or kills the learning process, since folks can't fully focus on their jobs. And or a strong crew may be carrying a weak skipper so much that the skipper has an overinflated sense of his capabilities.

One other aspect to this is that once folks are mostly confident with the basics of handling the boat, have the training officer start introducing mock casualties. Such as telling the skipper that one of his 2 engines just shut down, or that it turns out that springline X isn't quite long enough, got dropped into the water, etc.

All very good advice.

I don't have any problem using spring lines single handed - I just run them to the cockpit. The key is not to use too heavy line for them. -- they don't have to be like your dockhead lines. I use an old 12mm dyneema halyard usually.

Complex harbour maneuvers are the ultimate test of crew management in my opinion. Isn't it a joy to watch a well managed crew execute them? The calm voice of the skipper, the deliberate, unhurried movements of the crew, the vessel responding just so, always on the right side of wind and current?

[UNCIVILIZED]

BTW, perhaps it's best to think of the bow thruster more as a station keeping tool for the bow, or relatively so. Such that it's used to keep the bow in the same spot, or a "safe" spot. While you use the main engine & rudder to manuever the boat. And to use the thruster less to (try to) manuever the bow, or entire boat. Especially given the power & efficacy difference between it & the main engine(s) & rudder(s).

For example in an onsetting wind situation, when backing out, once the bow's 2m away from the dock, use the helm & prop to back & fill, in order to get the stern moving transversely away from the dock. Followed by putting the rudder amidships for a quick moment, & giving things a shot of forward throttle to still any aftwards motion of the boat. So that you don't wind up backing into the guy astern of you. Then repeating these steps as needed until you can power away from the dock in the conventional manner (ahead or) astern, with little helm input till well clear of everything.

The same holds true when docking, only that you'd use forward throttle combined with the rudder to get the stern moving sideways towards the dock. Along with shots of the prop astern with the rudder centered, in order to keep the boat well positioned fore & aft relative to fixed objects ashore, or one's neighbors.

One other BIG "help" is to go & practice on a racing boat who's prop is at the aft end of her fin keel, such that there's zero thrust generated by water flow over the rudder. And that you have to be moving at 2-3kts in order to get the rudders to have any effect. A boat setup like this but having twin rudders is even better. As in both configurations you're forced to learn to "catch & throw" the boat, & at much higher speeds than you're used to or comfortable with.

It's akin to judging how fast to get a car moving so that she has enough momentup to get up a hill that's too slippery to climb via tire traction & throttle, but to get her moving just fast enough on flat ground so as to come to a stop, or near there to when at the hill's top.
Uncomfortable, for most, yes. But a great skill to learn. Same with boats. And it's yet another good reason to "cross train" on different boats as much as you can. Which, as much of a pain as it is, it's best to train on those that are the hardest to handle/least responsive, etc. As you learn to judge & anticipate things far, far further in advance.

Hope the above dissertations help. Oh, & quite literally sit down with your reference books on docking, prior to actually doing any of these drills each time. And have all of the crew present for said "chalk talk", & explantaions of things.

Including going so far as to writing down each crewmans responsibilites & sequence of things that they need to do when docking or undocking various ways, on a legal pad. With inputs & questions from everyone. And make each crew/position laminated 3"x5" cards with the by the numbers actions for their position, that each type of docking situation requires. With everyone's cards clearly labeled at the top with the type of situation that the each card is for. Such as "kicking out stern with prop, while springing bow". Or "side tying at the fuel dock in negligable winds".
Then they just refer to that notecard, & follow what it says when you order it done.

One last thing. And this is KEY. Have Everyone onboard take turns doing each & every job, including & especially being the skipper & giving commands. And giving them Loudly, clearly, & in the earlier noted standardized language.

It makes for building a much, much better team onboard, as everyone is involved with all of the "fun" jobs, as well as the stressful ones. The job cross training helps them to understand the why's behind doing X, & Y a certain way. As do the "chalk talks". And it makes them all around better sailors & crew. Plus when a mate asks if he can borrow the boat for a date, you'll know whether he's a competent skipper or not, & can give him the thumbs up or thumbs down.

PS: "Write In The Rain" paper (& products) rock! It's worth the extra cost for notes to be taken or used above decks. Also, Map Proof for waterproofing papers & charts is great too. It makes things waterproof, & as a perk, makes paper about 4x stronger than without it. Nikwax | Map Proof - Sponge-on waterproofing for maps and charts

To best apply Map Proof, lay some bubble pack on a flat surface with the bubbles side facing up. Then lay the papers or charts onto it, & apply the Map Pruf. This method makes it so that when the Map Proof dries, your papers don't stick to the bubble pack. Unlike is the case when you apply it to papers resting on flat plastic sheeting.

[nigel1]

If I need to spring off hard, I really over fender the bow or stern, depending on which end remains in contact with the pontoon/dock. I have one of those 5 step boarding fenders


Which I hang horizontally over the side, which does help a lot, but I can see the real problem with the anchor if you need to spring off to a great angle.

My present berth is sandwiched between a pontoon and a harbour wall, with RNLI lifeboat's berthed close ahead and astern.
Although I have a bow thruster, it is rarely used, and I dont think it would help much in conjunction with a spring, although, as soon as you start coming a stern, you can use a very short burst to push the bow away from the dock.

As with a lot of docking maneuvers, you think you have it all worked out, planning one step ahead, and at the very critical moment, up comes a 30kt gust of wind.

As I single hand most of the time, I plan my departure from a berth before I even arrive. Have the boat pointing the best way for the forecasted departure weather and tide. For me, I prefer to use the stern spring, it's easier to let go from the cockpit. One trick for the forward spring, if the dock has typical marina cleats, use a small eye in the spring, and place it over the horn of the cleat which faces your stern. You can spring ahead on this, and then when you go astern, the eye should slip off the horn. This works on 90% of occasions, the other 10% are a real nightmare.

[UNCIVILIZED]

nigel1, cool fender/ladder. I've not seen one of those before, but it looks handy. And also makes me think of fender boards. Which can help a lot. They provide:
- More standoff distance from the dock. Including positioning them so that one end projects out past the bow a bit, so as to prevent the pulpit & anchor from kissing the dock.
- They spread out fendering loads over multiple fenders. Making individual fenders less likely to pop or get holed due to compressive loads.
- They protect the fenders & the hull from rough quay walls or docks. Including those with nasty projections, or that are coated in creosote, etc.
- They prevent fenders from rolling or being pushed out of position, thus putting you in an Awlgrip vs. concrete situation (hull directly against the dock).
- Can be hung at an angle so as to provide protection from multiple surfaces in different locations. Such as the low floating section of the dock proper, along with it's pilings or piers which stick out further horizontally, & higher vertically.
- Are easier to grab from the dock; to either horse into better position, or to use as impromptu handles to grab the boat. Providing for a much more ergonomic gripping surface than an extruded aluminum toerail.

And probably lots of other helpful things I'm forgetting. Which by all means, please list those I've neglected to.

[nigel1]

The one disadvantage is stowage, but like you say, biggest advantage is they do not roll, and work like a short fender board. I used this extensively when I transited the Crinan Canal last year.

[IdoraKeeper]

Indeed, springs fore or aft are useful. The issue of mashing the bow into the dock is painful, even worse, the stern on my boat. The stern hung rudder is quite vulnerable. It's always a bit nerve wracking since Idora is an unguided Juggernaut in reverse. If I have crew we use the dink as a tow boat, if there is dock side help we hand line her out. The limits and characteristics of a full keel are usually lost on power boaters who view these evolutions as incompetence..? Somehow. Bottom line, the Skipper needs to have full control of the vessel to avoid mashing the adjacent vessels.
I once saw a fellow Ingrid owner back off a fuel dock, execute a perfect left 270 into his assigned slip, bow out. He pulled up perfectly next to the dock.. Crew had at least 5 seconds to get the spring line on the dock and made fast... But NO! They just stood there and the wind took control. Next thing you know they are up against the neighbors and the Chinese fire drill is in progress. Ahhh the joys of boating:-).

[ranger58sb]

Originally Posted by IdoraKeeper

Crew had at least 5 seconds to get the spring line on the dock and made fast... But NO! They just stood there and the wind took control. Next thing you know they are up against the neighbors and the Chinese fire drill is in progress. Ahhh the joys of boating:-).

I think that's one of the points I often have trouble making new crew understand: during tricky approaches were we're likely to have one and only one chance for an elegant landing or departure

Some things, especially with spring lines, need to be done RIGHT NOW!!!! else an otherwise perfect maneuver can turn to crap in a heartbeat.

I'm beginning to experiment with practice sessions beforehand, even when we're just hanging around on the boat in the marina...

-Chris

[Dockhead]

Originally Posted by Kenomac

I can't really explain what I do when the time comes because every situation is different, but I don't hesitate to use the bow thruster in short bursts and ample use of fenders. Just make sure you never get yourself in a jam where you need to use the thruster too much, because it will trip the thermal shut down, then you'll have nothing for about a half hour until it resets.

Spring lines are really tough without onboard assistance. But one thing is for sure, I always prefer to put myself in a situation where I anticipate backing out instead of head out in forward. I just feel like I have more control not having to worry about the stern or davits hitting something. We're a center cockpit like you, so it's very easy to forget the stern.

One technique which has proven valuable is to be able to do a 360 pivot within one boat length using only the engine.

Yes, if you're trying to get out against the wind, always back out, so that the wind is working with you instead of against you, to pivot the boat in the right direction. Actually, any time you need directional stability when moving against the wind in the harbor, it's better to be in reverse.

And isn't the bow thruster worth its weight in gold, when maneuvering in reverse in the harbor -- like having another rudder at the bow.


I have never in eight years tripped the thermal breaker of my 10 horsepower Sleipner thruster. I just don't use it for more than 10 seconds at a time. If you need it for more than 10 seconds, you're doing something wrong -- is the way I look at it. The thruster is not all powerful -- it will not swing the bow into a strong wind and will not hold it up against a strong wind. You have to do something different, if you need to get the bow up into a strong wind.

[Dockhead]

Originally Posted by ranger42c

I think that's one of the points I often have trouble making new crew understand: during tricky approaches were we're likely to have one and only one chance for an elegant landing or departure

Some things, especially with spring lines, need to be done RIGHT NOW!!!! else an otherwise perfect maneuver can turn to crap in a heartbeat.

I'm beginning to experiment with practice sessions beforehand, even when we're just hanging around on the boat in the marina...

-Chris

Yes, but that is really 99% up to the skipper, to get this performance out of the crew. It takes a very clear explanation, and then confirmation that you have been completely understood, then it takes effective communication during the maneuver itself. If practice is necessary, then the skipper must be able to discern that and then provide the necessary practice. The right skipper can get this much performance out of practically a monkey. That is skippering 101.

[ranger58sb]

Originally Posted by Dockhead

Yes, but that is really 99% up to the skipper, to get this performance out of the crew. It takes a very clear explanation, and then confirmation that you have been completely understood, then it takes effective communication during the maneuver itself. If practice is necessary, then the skipper must be able to discern that and then provide the necessary practice. The right skipper can get this much performance out of practically a monkey. That is skippering 101.

Yep. absolutely, it's on me, no question.

This "speed needs practice" thing is one that took me a while to recognize... so I'm working on me and the crew practice is secondary.

-Chris