Hull Thickness & New Stabilisers 1984 61MY

[kelpy]

It is an easy place to pick up the cooling water. The adaptors usually already have a handy threaded hole to use. The engine will never miss the diverted sea water. The water used is at ambient temperature- the same reason it is used for the gear and fuel coolers before going to the engine heat exchangers. The oil gets very hot. To me, if you are not using a dedicated electric cooling water pump for the system, it seems to be the most logical access point. And, it is where it gets picked off on my 16-92s for the Naiad stabilizers. YMMV

[scottinsydney]

I actually disassembled the Jabsco elbow when checking everything. It appeared that the elbow was drilled and a 1/2" copper tube inserted 2" inside the elbow cap. The copper tube was silver soldered to the elbow. Very simple. It just did not have enough pressure to send water up to the ceiling at 900rpm as per the old hose run.

[Pete]

Kelpy, there are three possibilities for using engine cooling raw water for ancillary heat exchangers/coolers. First, and best, IMO, is the setup that locates the ancillary cooler after the main engine heat exchanger. Second best is as you describe on your engines where the ancillary cooler is before the main engine heat exchanger, but the raw water remains in the flow to the main engine heat exchanger to pick up additional BTUs, and third and least desirable by far, again IMO, is diverting the raw water to another unit and then dumping it overboard.

A suggestion to scottinsydney, get a thermometer and measure the temperature of the discharge water from the stabilizer oil cooler. To the extent that temperature is below 180F, that will tell you your lost BTU cooling to the main engine. To calculate that BTU loss you would also have to determine the flow, but empirically you will know if you are dumping warm cooling water overboard or something approaching 180F. BTW, I seriously doubt it is anywhere close to 180F as it is going through vinyl drain hose that would not stand up to those temperatures.

Pete

[scottinsydney]

Today I visited the warehouse to see the fins that have just arrived from Holland. They are made of stainless steel. They are maybe twice the size of the old stabiliser system fins.

Interestingly there is a large Oring that will sit against the bottom of the already installed bush. 8 bolts hold the fins' plates to the hull. There is a very big circlip at the top of the bearing housing that stops the fin falling out while the bolts are being tightened.

In a previous post a forum member asked why I chose this particular system. The answer was actually twofold... because the manufacturer allowed me to oversee the project myself; and what I forgot to say....... that the special water seal system that was especially developed for these stabilisers should never need to be replaced. You just squirt some grease in the top of the shaft once a year.

Fin3.jpg
New fins in the box.

Fin2.jpg
Large Oring that presses on bottom edge of the bush when bolts are tightened.

Fin1.jpg
Top of shaft. Circlip is removed prior to fin installation and replaced after bearing is inserted into bush. The circlip rests on the top flange of the bush holding the fins up while the 8 thru hull bolts are tightened up.

[scottinsydney]

So its a very happy, albeit expensive week, in my stabiliser project. Its now taken about 18 months or so from the time of the first components order. I did most of the work myself, excluding the hull. Great fun learning about hydraulics. And its cost about what I thought. My wife is pleased, but now ready for me to start another long term project. What more can I say!

After much preparation it was great to see the fins lifted into place. Not so great to find that a measurement was incorrect and adjustments had to be made to the hull for the fins to mount correctly. Problem was analysed and solved quickly and yesterday the fins were put into place.

Fin1.jpg
Here is a patch over the holes that were prepared 3 months ago.

fin5.jpg
Ensuring that the stabilisers' exterior flange would sit on a perfectly flat hull as measured with a straight edge.

fin4.jpg
Lifting the stabiliser up for a test fit. We found from this that a measurement was not right. Problem was solved overnight.

[scottinsydney]

Once the bearing housing is inserted into the bush, a circlip is inserted at the top of the bearing. The circlip rests on the top of the bush and prevents the fin falling out during installation or removal. Quite clever, but tolerances are very tight. There is no room for error.

fin6.jpg
This is the most satisfying photo I've taken in a long time!

My boat is 70' long with the 9' cockpit extension so I chose the largest fins Vetus had which are 0.7sqm or 7.5sq feet. This seems to be about 2.5' larger in surface area than the fins we removed. We cruise at 8.5 knots so hopefully it will be a good fit. (Indeed, our boat without stabilisers and in a side on swell is unpleasant.)


On the inside of the hull, the procedure to connect up the fins' shaft to the hydraulics is straight forward and took about 30 minutes for each side. First the fins are centred and a yoke is placed on the fins' shaft and locked in position. Next is a large washer, then a spin-on housing with 6 bolts. The bolts are screwed down and torqued to 56NM. The yoke is now locked to the shaft. The hydraulic rams are set in position and a couple of squirts of grease are applied to the three nipples.

According to Vetus, the specially designed bearing seals incorporated into this stabiliser system will never need to be replaced. Every year you simply add a few pumps of grease to the three grease nipples. These new seals suit me because I never, ever, want to remove these fins.

fin7.jpg
This photo shows the completed hydraulic housing. There are 8 though hull bolts . You can just make out the circlip under the white yoke. The spin on disc sits atop the yoke and it's bolts are tightened pushing the yoke firmly against the shaft. This locks the shaft to the yoke. Pretty simple and I got to try out my new torque wrench!

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With the boat out of the water for a week, we are Propspeeding the running gear and rudders, new anodes, changing the antifoul colour to red and recreating the original blue bootline that a previous owner had antifouled over.

The completion of the stabilisers is the last in a long list of mechanical and electrical enhancements we committed to doing when the boat was purchased a couple of years ago.

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So the only thing now is to splash the boat on Monday and see what happens.

[Pascal]

Congrats on getting the fins in and ready to splash!

I m going to pick up mines next week... i got a set of used fins and actuators from the local Trac dealer, with new seals and i ve ordered the rest of the hydraulics and electronics new from Trac. Will be installed during the upcoming repower. My boat has a vosper mini fin system which never worked. It had been installed back in 1970 for $4000 right here in miami by Merrill Stevens according to the invoice i found... i was going to juset close the holes but got a deal i coudlnt pass on the Trac system

[scottinsydney]

So the boat was splashed and we all headed to the engine room to see if the new fins were leaking. Thankfully they were not.

The boat was towed to a mooring where we set about replacing the flooring, including a new piece of timber under the port battery bank. Water had been allowed to drip down by a PO from the kitchen sink drain above and had rotted out the flooring. Over time the sides and edges of the battery boxes had broken off, but most bits were found and fibreglassed back together.

The four large centering (emergency) bolts were unscrewed on the stabiliser hydraulic housing. The fins would now be able to turn freely.

The system is powered by the starboard ignition with 32 volts. We used a couple of buck converters to obtain 24 volts required for the stabilizer system's electrics. Seems to work fine.

Everything associated with the new stabiliser system from power to hydraulics is associated with the starboard engine.

With great excitement, and after nearly 16 months, we turned the stabiliser control on and then the hydraulics master solenoid on. There was only one small oil leak from a port side hydraulic ram fitting. This was quickly nipped up.

We let go of the mooring and went to find some swell. The ocean was dead calm and the highest swell was less than 2'. After about 5 minutes oil seemed to be getting though all the hoses and sugddenly the boat started rocking the wrong way! Each roll in the 2' the swell was magnified. A quick call to my Vetus rep and we switched around a couple of solenoid plugs and problem solved.

Further calibration called for the setting of the pressure. For this the fins are told to push out to full extension so the system can calibrate the pressure against them. The last test was called the roll test. At 5 knots, the boat is rolled from side to side until it can roll no more. The system then saves this information. I'm glad I only ever have to do this once. I'd have loved to have seen a video of this procedure from the stern.

All good. So we embarked on a 20 mile voyage back to home base. Lots of humpback whales and calves heading south to the antarctic for summer.

I'd never been in a stabilised boat before. There was some swell in the ocean and the stabiliser system worked really well. My coffee did not spill, the toaster remained on the galley bench. There was no lurching. I even dared to go closer to the Sydney cliffs to see what the effect of the swell's bounce back was...... the boat handled so much better. Indeed it was an entirely different offshore boat.

I am now a stabiliser convert!

fin9.jpg
Antifouled and ready to go!

fin10.jpg
Sikaflexing the repaired battery boxes to the new floorboard.

[Pascal]

Congrats. Once you get stabilizers you cant live without them !!