Autopilot for sluggish response helm

[Sconno]

Hi all. We took a 35' steel ketch motorsailer for a test sail yesterday with a view to purchasing her. She is ticking a lot of boxes for us, but I am asking for feedback on the autopilot feasibility question. The current owner said he removed the previous autopilot because it drained the batteries. The wheel steering feels pretty heavy, it requires more force than I am used to using to turn the wheel. It is a hydraulic system with a pump driven by the wheel pushing fluid through hoses to the ram which turns the quadrant. See photos of the vessel and also the drawing and pictures of the underwater features. She has a full centre keel as well as 2 smallish bilge keels to dry out on. I understand that these features make her very slow to respond to helm input. I am wondering about what type of autopilot I should consider and how difficult it would be to set up? If you turn the wheel a 1/4 turn, you then have to wait 5 - 10 secs for her to respond, which we can get used to, you just have to be patient and avoid over steering. My concern is that an autopilot would struggle to cope and therefore run the batteries flat. And yes, I know it is a motorsailer, and you would probably be using the engine so the batteries would be receiving charge. But I would like to use the autopilot when not using the engine as well. As well as when singlehanding. Many thanks in advance. I have outlined the main underwater features on one of the pics.

[coopec43]

Can we ask what the design of your yacht is?

In the meantime here is a link that might interest you. (There is a video but I'm not sure how to link to that)

https://www.nauticexpo.com/boat-manu...ing-43846.html

[Sconno]

Thanks for the response. She was designed by G Breekveldt and built by Transweld in Auckland NZ. That's all the info I have. I have spent about 20min Web searching both those names, but there is not a lot of info out there

[coopec43]

Sconno


I presume you came across these links?


https://www.stuff.co.nz/national/687...-design-flawed


https://www.sailboatlistings.com/view/88559


https://sailboat.guide/zxc3nj



https://www.sailboatlistings.com/view/92532


https://www.inautia.com/used-boat-27...505054455.html


To my uneducated eye the rudder is too small for a long keeled yacht

[kiwin]

Most autopilots demand a 10s or less hard over to hard over time. In general a pump can be sized to do that. If your boat does not respond to the helm then the autopilot is the least of your worries. How do you expect to be able to steer in a seaway?

[kapnd]

I’d start by bleeding the hydraulics, trapped air can make steering sluggish and unpredictable!
Beyond that, heavy feel at the helm may mean that the system components were selected
Without due diligence, and are not ideal for the boat.
Most autopilots websites offer a thorough guide to selection of components, maybe you should go over that as if you were buying a new system, and compare the recommendations with what’s actually there.

[rhubstuff]

"To my uneducated eye the rudder is too small for a long keeled yacht."

I agree absolutely with this. Also, the steering wheel should not be at all difficult to turn. I ran a 55 foot motorsailer for three years with an identical steering system, and at both steering stations, the wheels turned without effort. You could almost spin them. I think your hydraulic system is either malfunctioning or under-sized. In either case, the problem is solvable. I love the design! Good luck with her!

[Bill O]

https://www.youtube.com/watch?v=KQuBwLSMSxI

[Celestialsailor]

First, a hydraulic system should not be hard to turn. There is something wrong. My Hallberg Rassy had it's original Vetus set-up and although it was easy to turn, it was 3/4 of a turn before the rudder would respond. I adapted a new helm pump and she came back to life. It needs to be surveyed to determine what is binding up. Could be a bent rudder shaft for that matter.

[Sconno]

Thanks once again for all the input.

I had not seen the article about the Owenga Class Fishing boat stability issues. Apart from being designed by the same guy and being similar length, is there anything else that you, Coopec43, think is a red flag regarding the stability of the bilge keel motorsailer? The Owenga doesn't look at all like the motorsailer I am looking at. But then you can't easily compare the underwate profile. When we were out on her the other day we had gusts of 20-25kt and she barely heeled. Seemed pretty stable to me. And the current owner is an old guy with tones of stuff on board. Boxes of spare parts, full fuel tanks (1000 litres) etc so I am surprised to read about the instability of the Owenga's. I will do some more digging. All comments welcome.

And Sean d'Emagnier's Pypilot is amazing. Thanks for sharing Bill O.

I see there being 2 issues with the steering: The difficulty turning the helm and the size of the rudder. Both of them are solvable.

The top of the rudder stock is visible in the cockpit so you can see that the rudder turns exactly as the wheel turns. The problem I was talking about is the delay in the vessel responding to helm/rudder input. The size of the rudder could be the answer to this.

[coopec43]

Sconno

I found a report on the capsizing. I should read the whole report before expressing an opinion. But 6(?) passengers alone weighing (say) 220lb each would amount to 1300lb well above the COG. I haven't read the conclusion of the report in detail but the vessel had been modified apparently: I'll let you decide. Here is the link to the report.

https://www.taic.org.nz/sites/default/files/inquiry/documents/12-201%20Final.pdf


Report 12-201 | Page 1
1.Executivesummary
1.1.At about 2000 on 14 March 2012, the fishing vesselEasy Riderdeparted Bluff for Big South Cape Island off the west coast of Stewart Island.The skipper, 2 crew members and 6 passengers were on board.The passengers were to be offloaded at Big South Cape Island, where they were to prepare for the upcoming muttonbird harvest. The skipper intended then to
travel to his fishing grounds to engage in commercial fishing.
1.2.The weather at the time that the vessel sailed was described by local fishermen as poor. It was forecast to deteriorate further as a frontal weather system passed across the Foveaux Strait area.The wind was forecast to increase to about 40-50 knots from the northwest before easing to 15 knots from the southwest after the weather front had passed

[Sconno]

I have read the relevant sections of the report and am convinced that the stability issues discussed do not apply to the vessel we are considering.

Here is my summary of a comparison between the two vessels. Easyrider was the one that sank in March 2012. Electra II is the one we are thinking of buying:

[see new image attached]
* I am not 100% sure of the length of Electra II. I have taken the max and min values from the available info.

The differences in draft & beam are sufficient to make me believe that the designer didn't simply modify one design to make the other.

[nortonscove]

Originally Posted by Sconno

Thanks once again for all the input.

I had not seen the article about the Owenga Class Fishing boat stability issues. Apart from being designed by the same guy and being similar length, is there anything else that you, Coopec43, think is a red flag regarding the stability of the bilge keel motorsailer? The Owenga doesn't look at all like the motorsailer I am looking at. But then you can't easily compare the underwate profile. When we were out on her the other day we had gusts of 20-25kt and she barely heeled. Seemed pretty stable to me. And the current owner is an old guy with tones of stuff on board. Boxes of spare parts, full fuel tanks (1000 litres) etc so I am surprised to read about the instability of the Owenga's. I will do some more digging. All comments welcome.

And Sean d'Emagnier's Pypilot is amazing. Thanks for sharing Bill O.

I see there being 2 issues with the steering: The difficulty turning the helm and the size of the rudder. Both of them are solvable.

The top of the rudder stock is visible in the cockpit so you can see that the rudder turns exactly as the wheel turns. The problem I was talking about is the delay in the vessel responding to helm/rudder input. The size of the rudder could be the answer to this.

The general shape would indicate good initial stability which sadly is often traded for poor ultimate stability. Looking at that boat I'm seeing a motor yacht with decorative masts. I wouldn't worry too much about power consumption as it isn't likely to sail very much. The delay in the system isn't unheard of. We once chartered a tugboat that had something like a seventeen second delay. It takes some planning when maneuvering in tight quarters with a barge on the hip.

[Bill O]

Originally Posted by Celestialsailor

First, a hydraulic system should not be hard to turn. There is something wrong. My Hallberg Rassy had it's original Vetus set-up and although it was easy to turn, it was 3/4 of a turn before the rudder would respond. I adapted a new helm pump and she came back to life. It needs to be surveyed to determine what is binding up. Could be a bent rudder shaft for that matter.

I'm will have to agree w/Celestial that there is something wrong if a hydraulic steering system is too hard to turn the wheel/rudder. Ours is an old Wagner system and it's been rebuilt. It works very well hand steering or under AP. We have a below deck hydraulic AP pump and it doesn't drain our batteries. In fact, it takes very little power to sail all day compared to other "brand" APs.

The other issue you mentioned the rudder maybe too small. Do you have any pics of your rudder? We made a new rudder for our boat when we realized a PO installed a barn door rudder that was literally a flat board. The "hard steering" while sailing in heavier air was due to the rudder having no lift. When we made our new rudder (NACA0010) design, we made the rudder smaller, not bigger. https://phoenixketch.blogspot.com/20...er-part-2.html

Again haven't seen your rudder, but if you want to weld up a new one, research Dave Gerr and his high lift rudder designs or make one like in the attached paper to give you a more balanced rudder for easier steering.

[Bill O]

Originally Posted by nortonscove

The general shape would indicate good initial stability which sadly is often traded for poor ultimate stability. Looking at that boat I'm seeing a motor yacht with decorative masts. I wouldn't worry too much about power consumption as it isn't likely to sail very much. The delay in the system isn't unheard of. We once chartered a tugboat that had something like a seventeen second delay. It takes some planning when maneuvering in tight quarters with a barge on the hip.

Looks can be deceiving and it really comes down to SA/disp. numbers, not just appearance. Many come on our boat and call it a tank or a motor sailor, when in fact it sails fairly well even in light air (w/the proper sails up). Will say we aren't the fastest, but not the slowest either.

The dirty truth is many "sailors" motor more than they like to admit. The real facts are told w/the number of hrs on the hr meter. Obviously many different factors are for motoring more which include low SA/disp numbers (light air), impatient people and poor sailing skills.

With all the deck structure the OP's possible boat will have some windage, but that can be over come.

If comfort is the main game, then go for it.