Chine/keel "walking"

[CTdave]

Hi All!
Boat: 94 50c with MTU 1175hp. Cruise: 28 kts @ 1950. 30kts @ 2100. 32kts at 2400.

Anyone have experience with what I understand is called "keel walking"? I have heard of it on some other manufacturer's boats but not Hatteras
I know lots about chine walking on fast v-bottoms but this is a much slower, occasional "lean" to one side or the other.
I can be running in flat calm or sloppy stuff & occasionally, she will list over to one side or the other. Nothing major but enough to hit the tabs for a medium adjustment.

Anyone else have experience with this?

David

***UPDATE: Well I found a few contributing factors, all due to me.
The lean would happen more to the port side. I would drop the port tab to even things out.
After thinking about weight distrobution, I checked a few things.

Port water tank full, starbord empty. Front fuel tank full, rear empty.
I need to even out the water tanks & get fuel in the rear tank!

I believe I solved my own issue!!!

 

[rsmith]

Back in '86 Ocean put a pair of mans in their 55-SS I think they only made one as a demo boat. I got a ride on it up in Cape May where I was based out of at the time. Over 30kts the boat laid on its side and started to bow steer pretty scary. I dont know if they did something to fix it or not.

 

[34Hatt]

My 34C did that after I repower but it was worse anything over 25 kts and she would make a right or left. Tabs did not help.
It just happened that after adding the 8K generator in the middle in front of the rear bulkhead it never did it again. I was lucky for sure.

You need to talk to Captpl Paul is also in CT with a 50c with man's. I think that boat had the keel modified for that reason. But PM Paul he knows those 50C very well.

 

[saltshaker]

My 34C did that after I repower but it was worse anything over 25 kts and she would make a right or left. Tabs did not help.
It just happened that after adding the 8K generator in the middle in front of the rear bulkhead it never did it again. I was lucky for sure.

You need to talk to Captpl Paul is also in CT with a 50c with man's. I think that boat had the keel modified for that reason. But PM Paul he knows those 50C very well.

2 very different boats. Paul has an early '80's 50C series II. This is a newer 50C series III, completely different boat.

Dave,
Your 50C was designed with the higher speed in mind. It is one of the earlier hulls with the bigger engines so maybe Hatteras did some modifications on the later boats. I would call the factory to see what if anything was changed to address any keel walking. The 1300HP 3412's became an option on that boat and she will run in the high 30kt range. I heard Hatteras added 2 running strakes to break the effect of the keel or chine walking, but I can't say exactly how it was done. I'm sure if there are issues with keel walking they would have addressed it. Good luck with the new boat. The 50C is supposed to be one hell of a nice ride. How do you like it compared to the Bertram? How is the ER with the MTUs? I know they can be tight with the 12V92s and the 3412's.

 

[CTdave]

Saltshaker, thanks for the info. I'm following up.

I LOVE the boat & Love the speed! I will say that my 50 Bert was much more stable but it was only going 21 kts. The Hat is so much faster but with speed, I give up the smoother ride.
I've dealt with the keel walk for two summers now so it isn't a major issue. I just wanted to make sure something bigger wasn't happening or that I was doing something wrong. I hear the 54s had it much worse. My boat does not start bow steering or leaning over to the point where everyone has to grab onto something, it just leans over a bit.
I remembered stories of the Oceans with hull problems so & gave the stringers/hull a complete inspection & see that the tabbing, stringers & everything is in excellent shape.

I sent a PM to Paul to see what he knows of this.

Thanks everyone!

Dave

 

[CTdave]

Jack, I forgot one of your questions.....

The engine room is tight. I have seen much worse though.
I am 6' & 220lbs so not a small guy. I can still get all the way around the engines. Granted, not a stroll in the park but I can do it. The port side is the worst because the generator is behind the main engine so I have to squeeze between them. Once on the outboard side, there is room.
My biggest issue is that the batteries are lined up right down the center of the walkway. There is an area (3'x4' +-)on the starbord side at the rear bulkhead where I would think they shoud be. There still is 8" or so inches of room to walk but it's tight. Perhaps this is where the batteries originally were & might counter the weight of the generator? Perhaps the galley does it. I'm not getting into maritime engineering any time soon so I'll leave it be for now.

 

[Geoff58yf]

Back in '86 Ocean put a pair of mans in their 55-SS I think they only made one as a demo boat. I got a ride on it up in Cape May where I was based out of at the time. Over 30kts the boat laid on its side and started to bow steer pretty scary. I dont know if they did something to fix it or not.

I put an offer in on this boat mid 1990s when she was on the West Coast (SanDiego) and was called "Viper". Meanest, LOUDEST, fastest and yep, scariest ride you can imagine. The seatrial put an end to my interest real quick.. Also a Leprechaun couldnt have serviced the outboard side of those engines. I couldnt even get my arm down the side of them!

 

[rsmith]

Dickie Webber was the big O-chit Yacht dealer then and always had a blue hulled demo boat called the South Jersey champ. I think Don Leek tried to sell him this one. I have a lot of offshore trips in 55 O-chits. coming from Hatts its pretty unnerving to watch the boat twist and flex in a seaway (hence the nickname "flexible flyer") there were a bunch of the early ones that split alongside the keel. I even saw one with the keel snapped off when the travellift picked it up. I couldnt believe the keels were bolted on and not part of the hull. For a long time you couldnt get ins on the 55's.

 

[jim rosenthal]

I recall being told by a mechanic from Anderson Marine in Baltimore about this: he was looking at the engines (8-92s) of a 55 OY as they were doing a seatrial off Ocean City, MD, in a moderate chop- say three foot seas. He could see the engines moving back and forth laterally as the hull flexed and the engines wiggled. He said he'd never seen that on any other boat- the bottom was so flexible that the entire engine and stringer system could move that much. Lots of inexpensive speed, but maybe not so much safety.

 

[saltshaker]

I was on a 55 Ocean that did the same thing. The engines would wiggle every time you went over a wave. The 55's had an issue with the engine stringers rotting out so I thought this may have been the problem. When I mentioned that I was told that both engines had been removed and the stringers were rebuilt, stronger than original. All the movement was from the hull flexing.

 

[daniel r morrison]

I don't know about newer models but the older 42, 45 and 46 hatts had a very wide flat keel which caused conseridable keel walking at higher speeds. The boat would try and plain on the keel and eventually fall off to one side or another. anyhow with the price of fuel who wants to go fast.

 

[rsmith]

I do I just can't afoard it.