I've got a couple hundred miles on the stabilizers now and thought I'd report back on how they are working. I'm happy to report I'm still thrilled with the results and the performance. We've been out in a wide variety of seas, the worst being around 4-6 ft. We've had lots of opportunities with head seas, following seas, and quarter seas. With few exceptions, the boat just runs flat - that's all there is to it.
The other day I figured out how to get our roll displayed on the
Maretron display and can now actually put some numbers to it. Under
most conditions the boat won't roll more than 1-2 deg in either
direction. The worst I saw was 5 deg, and that was with a really
difficult side sea. With the stabilizers off, I was seeing 12-15 deg
rolls. In this worst case situation they are taking around 70% of the
roll out, and I'd say under typical conditions they take 95% of the roll
Mechanically, things are also going well. There is no sign of leakage,
either water or hydraulic fluid. I do have a small ooze from one of the
raw water pipe fittings at the oil cooler, but it's almost non-extent
so I'm planning to deal with it over the winter.
Speaking of the cooler, the hottest I've seen the hydraulic fluid is 100F, and the starboard engine (the one providing the cooling
water and running the hydraulic pump) operates within 1-2 deg of the
port engine and so far the max temp I've seen is 172F. From all this
I'm comfortable that the extra power load and cooling load are just fine.
Happy Camper and I.
Comments and discussion on this post:
And thanks so much for the report back. That's a valuable part of the write-up.
askaer: Now I am back to Singapore after a long break to Denmark.
We have not ourselves had enough time to test our Grand Banks 47EU since we had the GB factory to refit Trac Star Stabilizers.
We recognise however your enthusiasm on the effectiveness of the system.
We have had a bit of shake at low speed. We have had a few parameters
changed which helped. I shall revert later once we have had more time to
What is your observation with regards to lost speed and increased fuel consumption?
I added a few photos on our homepage www.askaer.com from a wonderful cruising in Copenhagen on a factory new GB47 - look at the blog. Kind regards
Tanglewood: Hello Heine,
Sorry I didn't see your post here until today.
Yes, at very low speed it does occasionally feel like the boat just got a
gentle bump. But my fins only go active when the engines are in
forward gear which means a minimum of about 4 kts of headway. I noticed the bumps when we were commissioning the system at the dock
and the interlocks that halt the system while stationary were disabled.
The fins were responding to boat movement, but there was no water flow
over the fins so they were not having much effect. But on an otherwise
still boat, you could clearly feel them twitching.
You have the stabilization at rest feature which I don't, so if you are experiencing it at low speed or at anchor, it may just be an artifact of that capability.
Also, there is some different feel to the boat while underway, but I've
always attributed it to the fins doing their job, and don't even notice
it anymore. I liken it the odd feel of any boat that you are operating
for the first, but after a few rides it all becomes natural.
As for speed loss, ABT predicted 0.5 kts top speed loss. I don't have very reliable data because
1) There was different loading (as in fuel and water) for the various measurements I've taken
2) My GPS speed readings typically fluctuate +- 0.5 kts to over a kt depending on sea conditions, so I estimate an average.
The result of all this is that I probably can't measure a difference of
0.5 kts which tells you how important a loss it is. But if I had to
guess (which I'm happy to do), I'd say I lost between 1/4 and 1/5 kt. Now that's off cruise speed of 20+ kts where the drag will be at it's max. At displacement speeds I'd say there is no loss, and my measurements might even suggest there is a gain.
All the same applies to fuel consumption. The bottom line with both is that I think any losses are insignificant.
Nice pictures from Denmark!
askaer: Great to hear from you. You are absolutely right that the boat acts
differently in the sea not least due to the counter balance movements by
the fins. I am very impressed on their effectiveness. My observations
are however that I am 1-2 kts slower, that the fuel consumption is up by
perhaps 0,5 liter per Nm and with more noise
in the cabins while activated. They work fantastic at rest and we have
succeeded to remove the shake at low speed (5-6 knots). I have not had
any other issues and I am very pleased with the result overall.
That let me move on to another question that perhaps you may be able to
address. In fact I wanted originally to install the Seakeeper Gyro
System without fins. Unfortunately as an after installation it would
have ended up too far at the aft (additional 500 KG) that I did not
like. Have you any information or comparison between the Seakeeper Gyro
Stabiliser system and that of TRAC fins for Grand Banks
or similar boats? Any out there who could provide pros and cons! I have
watched some videos of Seakeeper stabilizers that looks as effective.
Is that the case?
Tanglewood: I don't have any first-hand experience with gyro stabilizers, but can give the reason's I didn't pursue them;
1) Physical size. The only place they would fit in my boat was in the
laz, and as you say it would have put a lot of weight far aft, and
consumed valuable storage/utility space. The active fins don't consume
any space that was otherwise usable. This will of course depend greatly
on the details of your boat, configuration, size etc. Other boats will
not have this issue at all.
2) Weight. I don't know the exact weight of the fin system, but I'd
estimate 500 lbs. Not a huge difference compared to a gyro, but 2x none
3) Power. I run my genset only occasionally when needed. It does not
run all the time when I am on board. Gyro's all (at least all I've
seen) run off AC, and a lot of it, which would require 24x7 gen set
operation. It might be possible to rig up some sort of hybrid with an inverter
and batteries, but it's a big load to be doing such a thing. By the
way, my unwillingness to run a genset all the time (legacy mentality
from my sailing days) effectively precludes any form of stabilization at
rest since I don't have a power source. If you have a boat with 24x7
power, this too is not an issue.
4) This is all hear-say, but I've heard enough reports of marginal
performance regarding gyro's, where I've never heard anything other than
complete satisfaction with active fin performance.
I'd say much of the decision was particular to my own preferences and
the specifics of my boat, but the last point I don't think can be
Regarding lost speed and fuel consumption, that's a significant
difference. At the same time, you report almost exactly the same speed
as I get. Perhaps your earlier numbers were with a lightly loaded
boat? I do see a clear difference between a light and full (fuel and
wolfhound: Thank you, Tanglewood.
This thread, now about a year old, is Cruisers Forum at its best.
Any further experience or evaluations from you will be appreciated, as will be similar commentary from your Singapore counterpart.
Tanglewood: Thanks for the thanks. The stabilizers continue to work flawlessly, and we put over 2800 miles on them this year with about 1/2 of that out in very open water. Unless we are on a river or a lake, they are on all the time.
I haven't heard from Heine, but hopefully he's still reading CF and will chime in.