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pm22  
#1 Posted : 05 June 2018 23:01:46(UTC)
Rank: Newbie

Posts: 8

I recently bought a Parker 27 and I find that under sail the steering is perfectly balanced, just as I would expect, but under engine the boat wants to turn sharply to the left all the time.

If I let go of the tiller for just a fraction of a second, it goes over to almost full lock and the boat turns sharply to port. This makes it difficult to handle - for example, if I bend down to adjust the throttle and relax my grip on the tiller, I'm likely to experience a course deviation of 20 degrees or more...

It's worse at higher engine speeds. Today I tried to go at maximum engine speed for a minute and I could hardly hold the tiller straight.

I'm assuming it has something to do with the prop., but there are no vibrations or noise, and the engine performs as I would expect it to. It's a fixed, 2-bladed prop. The behaviour is exactly the same whether the keel is fully down or halfway down

Has anyone experienced this? Maybe it's normal for the P27?

All the best, Peter

philip linsell  
#2 Posted : 06 June 2018 08:40:24(UTC)
Rank: Advanced Member

Posts: 109
Location: CHICHESTER, west sussex

Peter
My 26 is just the same.
Unless I am in close quarters, when the engine goes on so does the tillerpilot, keeps things nice and straight and I'm free to do other things rather than the boring bit.
Philip
rascal
pm22  
#3 Posted : 06 June 2018 21:00:49(UTC)
Rank: Newbie

Posts: 8

Thanks for your comment, Philip.

When I'm travelling at speed under engine, the force on the tiller is so high that I doubt the autohelm could reliably cope. But the situation is worse at low speeds when, for example, I'm entering or leaving a marina or going through a lock. If I let the tiller go for a fraction of a second, the boat could swing through a right angle, which is not good in a marina or narrow channel!

I'd really be interested to hear from other owners as to whether their boats behave in a similar way.

P
philip linsell  
#4 Posted : 06 June 2018 21:47:25(UTC)
Rank: Advanced Member

Posts: 109
Location: CHICHESTER, west sussex

Peter
The load is nothing to that when sailing overcanvassed as we often seem to be in a 26.
At low speeds without autohelm I put the engine in neutral if I need to leave the helm, it goes straight then and carries way well.
Philip
Marvin Kowalewski  
#5 Posted : 07 June 2018 18:51:34(UTC)
Rank: Advanced Member

Posts: 50
Location: Port Charlotte, Florida

Hey Newbie,

Sounds to me that your boat is responding to engine torque (which I am sure your know about). Yet... I don't have such a "huge force" as you and Phil have. Yes...some torque but not that I can't "hold it" with my tiller pilot or comfortably steer with the tiller extension. I guess what I'm saying is the "force" is not heavy as you all seem to describe. Maybe compare props...and especially pitch. I have a two bladed folder..next time I'll see if I can find the pitch. One more thing...I did remove the lower metal skeg to decrease sailing drag.

Marvin Kowalewski
Parker 27 The Happy Seal
Marvin Kowalewski, Ph.D
pm22  
#6 Posted : 07 June 2018 21:37:19(UTC)
Rank: Newbie

Posts: 8

Thanks Marvin, that's very interesting.

Yes, it may well be due to 'prop walk', caused by the circulating cone of water coming from the prop., but I'm surprised it's so pronounced. I'm not all that experienced with owning boats - I've had two and sailed four or five others over about 40 years, but none has had any tendency to dramatically change course when under engine. The worst that's happened is that the boat slowly drifts off course, and normally the faster you are travelling, the more directionally stable is the boat.

But with my boat, there's a force of around 5kg (or 50N if you're being picky) on the tiller, so if you let go, even for a second, the boat immediately swings around by tens of degrees. At higher speeds the force is greater: at about 5kt I had to lean my body hard against the tiller to keep it straight, maybe 10kg. Had I let go, there would have been an instant course change of 90degrees! That was going up the channel through the moorings at Itchenor, so a moment of inattention could have caused a lot of damage!

Under sail, the boat behaves beautifully, with no steering problems at all.

At first I thought the prop must be out of alignment with the boat, but it looks OK, so it can't be more than slightly out, and not enough to cause this effect. If it's being caused by prop-walk, i.e. the top part of the cone of water coming from the prop hitting the stern and kicking it sideways, then it's a much larger effect than I've experienced on other boats.

I'm wondering if it's the wash from the prop which is hitting the forward part of the balanced rudder, thus pushing it sideways. Maybe the rudder is out of alignment...?

Yes, I'd be very interested to know the pitch of your prop, or indeed anyone else's...

All the best, Peter


Gilliane Sills  
#7 Posted : 09 June 2018 16:38:51(UTC)
Rank: Advanced Member

Posts: 93
Location: Oxford

I have no idea whether this would work - but I think I remember reading in the Super Seal handbook that it was recommended to raise the rudder a little when motoring to avoid a heavy helm. There was no explanation of the reason, and we never found it necessary ourselves. Also, I'm not sure that what you're experiencing could be described as a 'heavy helm', since it seems strongly in one direction - but it might be worth trying. If you slacken off the downhaul and then refix it in a looser position, it should be possible to lift the rudder just a little with the uphaul. We've rigged a three to one purchase on both the uphaul and downhaul to make them easier to manage.

Good luck...

Gilliane
Delphine, Parker 275, no. 41
pm22  
#8 Posted : 09 June 2018 20:33:48(UTC)
Rank: Newbie

Posts: 8

Thanks, Gilliane, I'll try that.
P
PeterL  
#9 Posted : 09 June 2018 21:48:24(UTC)
Rank: Member

Posts: 26
Location: Dover, Kent

Two thoughts :

Is the boat running bow-down ? or 'stern-light' because some load has been shifted ? that was previously in place ?
Have you checked the void under the foc'sle locker lining to see if you have taken on water there,perhaps by a leaking log instrument ? Or added chain ?
It's possible that the engine depresses the stern more than when under sail.


Is the rubber buffer which acts as a stop to define the full-down position of the rudder (see the manual for diagram/article about it) been lost ? Even a small increase of area forward of the defined balance line would upset steerage.

Fulmar of Hollowshore / Parker Seal 27 / #131

Edited by user 09 June 2018 22:13:54(UTC)  | Reason: Not specified

pm22  
#10 Posted : 09 June 2018 23:28:42(UTC)
Rank: Newbie

Posts: 8

Interesting points, Peter. I'll check them. Thanks.
pm22  
#11 Posted : 14 June 2018 22:42:22(UTC)
Rank: Newbie

Posts: 8


Yesterday I had the chance to take out the boat in calm weather to do some motoring, and found that raising the rudder slightly does have an effect.

Too much and it makes the helm very heavy, but with just a little adjustment the helm stops pulling to one side almost completely. I marked the rudder uphaul and downhaul when the adjustment was the best I could get it.

When the boat was out of the water, last winter, I didn't notice a rubber buffer. Is this attached to the rudder or the hull? Is the manual with the diagrams the one that you can purchase from the club?

Peter

PeterL  
#12 Posted : 15 June 2018 06:58:56(UTC)
Rank: Member

Posts: 26
Location: Dover, Kent

https://drive.google.com...pTMtO4/view?usp=drivesdk
https://drive.google.com...JYwLi3/view?usp=drivesdk

HI,am on board so tricky to copy but here are pics from one of my manuals,one purchased ,one original,two inherited.All slightly different dates.
I used rubber slightly thicker than the return legs on the channel which seems about right.Without such a distance piece you are bashing and tending to spread the channel.See article:rebuilding rudder stock,on website.Leaving for continent v.shortly.
PeterL
pm22  
#13 Posted : 15 June 2018 08:16:42(UTC)
Rank: Newbie

Posts: 8

Thanks,Peter. Have a great trip!
P
Marvin Kowalewski  
#14 Posted : 16 June 2018 16:50:16(UTC)
Rank: Advanced Member

Posts: 50
Location: Port Charlotte, Florida

TO: Peterl and newbie pm22

I want to tell you that the drawing regarding the position of the rudder ...straight up and down line is absolutely correct. When I visited Bill Parker in 2003, I asked about go fast stuff...(I was a racer) and he said the one major thing to look for is the rudder position...too far forward and it drags .I have a drawing he made showing that exact line...and he said about 2 3/4 at the tip leading edge.
I don't have a rubber bumper and never had one to gauge this. I just eyeball and "feel" the helm.

I will try to get prop pitch this week for you.

Sorry to respond so late to this one... I was in Boston, Massachusetts for 4 days .....you do remember Boston don't you??

:)

Marv Kowalewski
Marvin Kowalewski, Ph.D
pm22  
#15 Posted : 16 June 2018 18:07:06(UTC)
Rank: Newbie

Posts: 8

Thanks, Marvin.

I hope the tea party went well!

The prop pitch information would be useful, although I suspect it’s probably the rudder position that’s causing the problem. I had a look today, and I can’t see any block, rubber or nylon, but I’ll check it more carefully when the boat comes out of the water.

Thanks for your help.

Peter
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