Improved handling in reverse - Page 4 - SailNet Community
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post #31 of 43 Old 04-20-2008 Thread Starter
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Its a Yanmar diesel and it is turning clockwise, so the rh prop is probably correct. Wouldn't the prop walk be in the opposite direction when in reverse, though vs. that when in forward? I will run more tests next time I am on the water but the movement of the boat in reverse is fairly standard. Basically once I go into reverse the bow starts swinging to port and the stern to starboard, as she backs up - that is what I call "counterclockwise", not sure if this was a good way to describe it.
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post #32 of 43 Old 04-20-2008
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While I have not had to manuver boat with out a feathering folding prop. My boat has a max prop, generally speaking, I do not get prop walk. Altho a week ago saturday I was getting some, and one other occasion I did too. Overall my rig with a fin keel backs fairly easily. So that may help in the end if you want to go with a diferent prop option.

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I drives me dinghy!
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post #33 of 43 Old 04-20-2008
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brak,
Something's not right there; you're describing a boat whose stern should walk aggresively to port under astern revolutions.

Here's a link to a well done DVD that not only explains all of this but shows techniques for dealing with docking in different situations of wind and current as well as tight slips. I believe that it adequately explains the techinique that bestfriend and SimonV are using as well. It's well worth the money and includes a good primer on sail trim as well! Sale page for Captain Jack Klang

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post #34 of 43 Old 04-21-2008
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Yes the yanmar has a clockwise motor rotation but what is delivered to the shaft and then the prop? I don't know but what you are describing in reverse doesn't seem to fit at least to my understanding.
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post #35 of 43 Old 04-21-2008
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With the boat tied to the dock, put it in reverse at idle, look over the side. If most of the propwash is on the starboard side it's RH and stern will walk to port, if wash is on port side it's LH etc.
This is a standard method to figure this out real quick on any vessel you have to handle.
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post #36 of 43 Old 04-21-2008
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Stop

Why are you fighting the laws of nature? Full keel boats don't back down worth a tinker's damn. Quit fighting it. I assure you that you can not and will not win. Use reverse for one purpose and one purpose only and that is to gain enough room so you can get the pointy end heading in the direction you want to go.

I've owned a full keel Cape Dory for 5 years now and it still won't back down in a straight line... Learn how your boat handles and accept it and adapt.

I wouldn't consider backing into a slip if you put a gun to my head!! There was one occasion when I needed have my stern in the slip first. How did I get in? I came alongside slowly and tossed port and starboard stern lines to handlers on the dock who pulled me in, that's how!!
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post #37 of 43 Old 04-21-2008 Thread Starter
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Well, I am not keen on entering my dock in reverse either

The problem at this point is
1) entering head in when the wind is on my back or pushes me into the fairway
2) leaving dock under same conditions

Here is why reverse is important. As I was leaving (and coming back, same thing really) this time - I needed to turn to stbd (when leaving, to exit from the dock and turn to the open water, when coming back - to enter from open water and turn to my dock).
When leaving, I obviously have to use reverse When coming back, I tend to need it if wind is pushing the boat too fast, so I can slow down. Either way, once I do that - I start turning to port. So, I can't go back or slow down without turning the wrong way.

Anyway, I looked at all the comments on where the prop walk should be taking me and certainly this differs from reality, so something is wrong.
Can it be that my transmission is "reversed" (i.e. essentially the gear for forward and gear for reverse are somehow switched)? It sounds silly but I am out of ideas on this one. I will try again this weekend and watch the prop wash more, but so far this is what I've seen and behavior is well repeatable.

In confined spaces because of this I end up either having to always turn around that way, or try to turn more clockwise during forward motion than reverse takes me (which is not always pretty).
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post #38 of 43 Old 04-21-2008
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brak,
Irrespective of your particular conditions and boat, which I'm not exactly clear on, what you really need to do is to get a line on the dock. If the only way to do that is to let the wind set you down on the end of the dock or you come in until your bow touches the end of the dock, you need a line secured to the dock and then you can overcome those forces that are moving you in directions you don't wish to go.

In some cases, it is necessary to lay the boat across the end of the dock, suitably fendered, and then work her around the end corner and alongside. You'll use the line as a spring line but where and how you secure it on your boat will dictate what effect you can get out of it. Once you've stopped the boat's forward momentum and taken a strain on the spring line, you can walk the stern in either direction you wish it to go by using your engine ahead and your rudder to kick the stern in the desired direction.

Certainly try the suggestion of capttb above to confirm prop rotation. Your prop can turn either way, even though your engine rotates clockwise, it just depends on how the gears are aligned within your transmission.

The DVD I linked above is an excellent source of information on just the situation you seem to be in.

Another tool to hand, admittedly a pain to use but more than doable, is your anchor. You may find it easiest to, in essence, perform a "Med-moor". In any event, you can drop your anchor and then use it to control from drifting off either end of the boat. You can even drag it from the bow, without letting it set, and use it much like a spring line to work the stern to either side while using ahead revolutions. Practise that one in open water first. (g)

I think you'll find that dvd has many good ideas and is quite good at explaining them, both with models and then an actual boat. They don't dawdle on shipping them out either; I think I ordered mine and it was on the front porch when I walked upstairs. (g)

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post #39 of 43 Old 04-21-2008 Thread Starter
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sailaway, thank you for the write up. I may have made a mistake in using the term "dock" and this is what causes misunderstanding, though.I should have called it a slip - it is a narrow (less than 11 feet) head in slip that has wood piles on either side. I really need to watch what I type, don't I?

I actually do pretty well with regular docks, and don't have much problem either docking or leaving (in situation mentioned by PBeezer, I left a leeward dead-end dock in 20kts wind while having to turn around in confined space, all that essentially single handed, and there are no insurance claims yet Admittedly it could have been much better executed but I still figure the result is what matters).

I will be checking and re-checking prop wash asap - I really need to figure this out. I am also looking into a single-handle control. If a move from hard over to hard over while switching gears can take up to 15 seconds now, I can probably shave off at least 5 by using a better handle configuration (changing steering is not an option).

The boat is Hallberg-Rassy 35 1972 (Rasmus). She's a grand old lady with what is a modified full keel, I suppose (it starts 1/3 of the way in as a kind of a regular keel and follows all the way to the stern with a rudder attached).
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post #40 of 43 Old 04-21-2008
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Ah, the full keel sailboat in reverse . . .

rtbates said it all. You just never know where she'll go in reverse.

Things that have helped me, over 3 +- years of owning a modified full keel:

Getting some speed in reverse and putting her in neutral does work. If the wind isn't blowing. And if the sailing gods are smiling.

If I had a slip with pilings, I'd rig a line on a float to stop the boat. Can't remember what they call it, but people with slips formed by pilings use them.

Getting a better slip!!! Yours sucks. My old one sucked, but not as bad as yours. I break out in a cold sweat just thinking about trying to get into yours as described. I got on the wait list, and now I can leave and return without a coronary or a mental meltdown. (Yes, I know that statement is a dare to the sailing gods. If they exact retribution, I will report according.) I always use a spring line on a cleat to stop her.

Playing around out in the open helps. The best control I get is by alternating bursts in reverse and then steering in neutral, and bursts forward. I cannot imagine trying to use this technique without a single control. I think you're right that it would help you a lot.

Always remember, people with fin keels have NO IDEA what we're up against. Ditto power boaters with twin props.

Daydream of long, long cruises you will take. One exit from the slip, good for months or years . . .

Mary
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