Humphree stabilisation system?

[Deleted User YDKXO]

What does the panel think about this?

http://www.humphree.com/trim-and-stabilisation

Roll stabilisation at all speeds and pitch stabilisation underway. All powered by 24V DC and with compact components. Too good to be true?

 

[jimmy_the_builder]

They need to spellcheck their homepage. Apart from that, doesn't this all rather depend what you're after ie stabilisation underway, or STAR? Personally for my corner of the Med, zero speed is the bigger deal, simply because of the proportion of the on-board time you spend at anchor vs the time spent underway, combined with the amount of boaty traffic there is down here. I guess cost must come into it, but it seems hard to beat the Seakeepers at the moment.

 

[jfm]

It looks a pretty clever concept. Hard to tell if it is vapourware or whether any are installed- none of the boats pictured actually have the hardware fitted

I thought when I saw the dominator 80 drawing that they were using too-small fins and then the interceptors to help the fins a bit. But from the specs it seems the fins are a good size including 1metre sq (same as mine) versions.

CMC have patented the electric actuators so I wonder how they are dealing with that ( cmc's patent is questionable, but they still have the patent, though it is under challenge afaik). I wondered if this was a jv with CMC but it appears not because the electric actuator looks different from cmc's.

So, very interesting stuff. The 0.4 sq m fin would be suitable for 45-50 foot boats, which is interesting.

I rather doubt that it really controls pitch that much. Adjusting trim, even quite quickly as humphree interceptors do, isn't really the same thing as controlling pitch. You need a lot of boat speed for the trim effect to be apparent, and you won't have boat speed in a big pitchy sea. But it's good marketing! And if the things can cure roll then that's the main event

 

[MapisM]

it is under challenge afaik

Aha, is it?
So, there must be other stabs builders around (on top of Humphree) who don't trust hydraulic to be the best solution anymore...
One of these days, I must search for a comment that I believe to have posted, back in the days when BartW was fitting his stabs, where I envisaged that in a not so distant future we will look at hydraulic stabs as a thing of the past!

PS: I couldn't agree more re. the claims on pitch stabilization, they are simply ridiculous.

 

[vas]

interesting and compact setup.

If they sell it in bits, I'd get the .4sqm ones and skip the flaps bit which looks like it wont do much anyway.
so, what's the price going to be for them in a couple of years time (ie. after capital controls down here )
I'd probably pay 5K for the fins only on two conditions:

• JTB installs them on his Targa and reports they work
• they provide the s/w open to configuration

cheers

V.

 

[tico]

Powered by milk?

 

[BartW]

I don't get it what's clever about this,
what is clever about a combination of stab and pitch controll ?
I guess that most boats with stabs have sort of a trim system ?

any fin stab system that has zero speed stabilising has more than enough stab capacity at speed

or am I missing something ?

the online doc claims that the system can run during navigation without the genny running, OK good, they are not the first,
my stabs can run at anchor without ANY engine running, from the battery's 24VDC, for 2 to 3 hours !

its good to see that electric stabs come more in the field,
competition is good for progress

 

[wakeup]

Looks like a rather large hull whole required per side to take the actuator motor.

 

[Deleted User YDKXO]

For me the interesting claim is that the fins run off 24V DC and there is no need to power up the gennie underway which I guess means that it would be possible to run the fins at rest off the batteries for short periods although that would be a very short period given the quoted max 80A power consumption. Anyone understand why the servo motors for the fins appear to have 360deg rotation capability?

Agree that pitch stabilisation with the interceptors is probably a bit pie in the sky at least on a planing boat. Nothing is going to stop the bow of a boat falling into a big trough and crashing into the next wave

Still it is interesting times in the stab market. Hardly a week seems to go by without a new entrant or a new innovation

 

[BartW]

Anyone understand why the servo motors for the fins appear to have 360deg rotation capability?

its just the simplest way to make a electric system;
just look at it as electric motor with a gear and a shaft that can turn around,
if you want to limit, you can in the software,
CMC is limited at +/- 43° movement (iirc)

the ability for 360° is of no practical use apart from maybe maintenance, or installation, the system has no mechanical "zero" position,
you can program any position to be the zero position

 

[Deleted User YDKXO]

I don't get it what's clever about this,
why install two systems to cope with pitch and roll, if one system can do it all ? (my stabs can)
I agree you might want intersceptors or flaps for trim, but that's something else
or am I missing something ?

Maybe I'm missing something but how do fin stabs control pitch?

the online doc claims that the system can run during navigation without the genny running, OK good, they are not the first,
my stabs can run at anchor without ANY engine running, from the battery's 24VDC, for 2 to 3 hours !

Are your CMC motors 24V or 220V?

 

[BartW]

Maybe I'm missing something but how do fin stabs control pitch?

Oh I'm sorry, I confused "pitch" with "list,"
my stabs can't correct pitch, they can correct list

Are your CMC motors 24V or 220V?

the CMC stab motors are 230V,
the controll system is 24V
I have 2 x 5Kw invertors / battery chargers
the invertors are not only usefull for the stabs, but a few other nice features aswell

 

[longjohnsilver]

Maybe I'm missing something but how do fin stabs control pitch?



Are your CMC motors 24V or 220V?

Maybe lost in translation, our stabs certainly don't have any affect on pitch. If you look at the Humphree website it seems that the interceptors are basically trim tabs. Interestingly I had to search for a while to find the stab section. And whilst they claim 80a @24v it's actually nearer 85A. That's one hell of a current drain, and depending on where the batteries are in relation to stab position, will require pretty hefty wiring. As Bart says, maybe they'll be useful for a few hours at anchor but you'll still need to top up the batteries pretty smartish, either by running the genny or starting the engines. When actually moving I can't see any advantage over hydraulically operated stabs., either way at least one engine has to produce extra power to run them. It's for short periods at anchor where I see the real advantage.

 

[BartW]

And whilst they claim 80a @24v it's actually nearer 85A. That's one hell of a current drain, and depending on where the batteries are in relation to stab position, will require pretty hefty wiring. As Bart says, maybe they'll be useful for a few hours at anchor but you'll still need to top up the batteries pretty smartish, either by running the genny or starting the engines. When actually moving I can't see any advantage over hydraulically operated stabs., either way at least one engine has to produce extra power to run them. It's for short periods at anchor where I see the real advantage.

J, I haven't checked if these 80 or 85amps /24 is peak or average

peak power on our stabs is much higher than that,
and average power is much lower than that

during navigation the engine alternators can easyly cope with average power, and the battery's take the peak power,
so there is a advantage during navigation (we use it all the time)

 

[jimmy_the_builder]

interesting and compact setup.

If they sell it in bits, I'd get the .4sqm ones and skip the flaps bit which looks like it wont do much anyway.
so, what's the price going to be for them in a couple of years time (ie. after capital controls down here )
I'd probably pay 5K for the fins only on two conditions:

• JTB installs them on his Targa and reports they work
• they provide the s/w open to configuration

cheers

V.

Ha! I don't think that's going to happen.

Apols to the OP - but when I read the Humphree page I didn't realise that they also work at zero speed, I misread 'all speeds' as 'all speeds underway'.

For the T40 I'd rather have a small gyro than any kind of fin stab, although even Seakeeper's smallest (the 3dc) is still too big to fit.

 

[longjohnsilver]

J, I haven't checked if these 80 or 85amps /24 is peak or average

peak power on our stabs is much higher than that,
and average power is much lower than that

during navigation the engine alternators can easyly cope with average power, and the battery's take the peak power,
so there is a advantage during navigation (we use it all the time)

Bart, difficult I know, but how do your electric stabs compare to the traditional hydraulic versions, are they just as effective?

We also use ours whatever the sea conditions, but I'm struggling to see the advantage of yours when under way re power use. Your alternator still has to work harder to replace the power used. Or am I missing something simple? Or maybe I'm just simple

 

[vas]

Is there any option on any of the el. systems (well actually asking Bart...) to LIMIT the current draw at anchor?
I mean, would it be possible to throttle the system so to speak so that your say X sized battery bank with Y capacity solar panels can REDUCE roll but not necessarily iron it all out?

I mean, having a system that can improve conditions on a particular anchorage without messing the batteries, or starting the generator.
I'm asking as in our area, uneasy conditions may exist up to late evening (when the sun stops being effective...) which is rather convenient for us. So a 500W solar panel setup (2 panels of 1.6X1m approx.) could in theory provide say 20A (or more?) at peak hours that could provide some stabilization compared to the 80A needed by such a setup. Does what I say make any sense (I'm currently in a boring meeting and trying to follow and post at the same time...)

cheers

V.

 

[Deleted User YDKXO]

When actually moving I can't see any advantage over hydraulically operated stabs., either way at least one engine has to produce extra power to run them. It's for short periods at anchor where I see the real advantage.

IMHO the big advantage of electric powered stabs is easier retrofitting in an existing boat. No PTOs and heavy hydraulic hoses to install. But yes, underway, I guess that, in principle, there is little difference in effectiveness although I'm sure that jfm will be along in a minute to put me right on that! Yup for me any stabs that can be run off battery power for an hour or 2 at anchor whilst I attempt to consume my lunch in peace would be attractive!

 

[MapisM]

For me the interesting claim is that the fins run off 24V DC and there is no need to power up the gennie underway which I guess means that it would be possible to run the fins at rest off the batteries for short periods although that would be a very short period given the quoted max 80A power consumption. Anyone understand why the servo motors for the fins appear to have 360deg rotation capability?

Agree that pitch stabilisation with the interceptors is probably a bit pie in the sky at least on a planing boat. Nothing is going to stop the bow of a boat falling into a big trough and crashing into the next wave

Still it is interesting times in the stab market. Hardly a week seems to go by without a new entrant or a new innovation

Funny, that you should consider interesting the fact that they are driven by DC motors, because the only reason I could think of while reading their webpage is that this might have allowed them to dodge the CMC patent. The advantages of AC vs. DC electric motors are so obvious that they are not even worth mentioning. And as BartW already said, they can be driven out of inverters.
Even without knowing the numbers, I bet that the overall current demand with the CMC system is lower in spite of the efficiency loss of the inverter. Also because at zero speed the efficiency loss is the other way round, when used for long periods: AC motors are directly feeded by the genset, while you need the genset and a rather beefy battery charger with DC motors.

Re. pitching, you say "at least on a P boat", but actually I don't even dare thinking what sort of forces would be necessary to stabilize pitching in any boat cruising at D speed.
You could probably achieve a better result by asking the crew to move forward and astern, compared to the what those interceptor things can do....!

 

[jfm]

Aha, is it?
So, there must be other stabs builders around (on top of Humphree) who don't trust hydraulic to be the best solution anymore...
One of these days, I must search for a comment that I believe to have posted, back in the days when BartW was fitting his stabs, where I envisaged that in a not so distant future we will look at hydraulic stabs as a thing of the past!

PS: I couldn't agree more re. the claims on pitch stabilization, they are simply ridiculous.

"Trust to be the best solution" doesn't describe it because electric/hydraulic is a horses-for-courses thing. Certainly electric can be cheaper, and is cheaper/faster to install, especially in retrofits. For the <20-25m it might become the better all-round solution, once some electric actuators without gearbox noise have been invented (which Humphree might have done here - I don't know). Another advantage of electric is 180 degrees rotation, to overcome creep forward at anchor, but the current holder of the patent isn't an outside-the-box thinker imho. If you're wishing to predict the future then forget the electric/hydraulic actuator debate because that is very limited thinking. The future needs much more creativity - for example just flapping like a big rudder on steroids isn't ideal. Mere actuator power choice is a side show when you think outside the box in boat stabilisation and imagine what could be manufactured in the future