Cheap Seakeeper 5 for small boats launched....

[rustybarge]

Looks interesting for boats under 20 tons and less than 50' for just $29k.....
360 kg
1.5-2kw on 110v........less than 1kw on 230v.

http://www.seakeeper.com/products/seakeeper-5

 

[Nick_H]

1.5-2kw on 110v........less than 1kw on 230v.

Same kw, less amps surely?

 

[vas]

very interesting!

the 75X75X62cm is a bit of an issue though on a sub 50ft craft.
Aren't you meant to install it low and along the central axis close to the COG, or not?

Unless you can place it symmetrically opposite to the genny (must have one!) I see not many places to fit it.
Guess wont like bilge water, so wont be able to dig it low just in case...

V.

 

[rustybarge]

Same kw, less amps surely?

I got thrown out of A level physics class after the first month! ( report said: lacks the building blocks of basic maths!)

ok, so....

15amps at 12 volts. Impressive!

 

[rustybarge]

very interesting!

the 75X75X62cm is a bit of an issue though on a sub 50ft craft.
Aren't you meant to install it low and along the central axis close to the COG, or not?

Unless you can place it symmetrically opposite to the genny (must have one!) I see not many places to fit it.
Guess wont like bilge water, so wont be able to dig it low just in case...

V.

Drawing on my vast knowledge of physics I would say the gyro would would exert more righting force the further it was above the cog...?

you could always fit a mini genny to run the Seakeeper, it only takes 15 amps dc 12v.

underway it could easily run off the alternator.

 

[vas]

Drawing on my vast knowledge of physics I would say the gyro would would exert more righting force the further it was above the cog...?

you could always fit a mini genny to run the Seakeeper, it only takes 15 amps dc 12v.

underway it could easily run off the alternator.

is that the knowledge that kicked you out of a-levels then

You actually may be right, thing is that it's a heavy noisy thing, you want it as low and as hidden in the bilges as possible. It does mention that it can work off-centre.

7-8A at 24V is very impressive, 2KW @220V is a decent hair-dryer (ok, runs fulltime and is less noisy...)
Surely on any planning 40-45ft craft with twin engines alternators would cope, and it wouldn't be difficult to get a scale down version of Bart's setup and run it of a decent 400-500Ah bank of batteries through inverters.

OK, who's first?

JTB, that should finish off your refit nicely I recon!

cheers

V.

 

[rustybarge]

is that the knowledge that kicked you out of a-levels then

You actually may be right, thing is that it's a heavy noisy thing, you want it as low and as hidden in the bilges as possible. It does mention that it can work off-centre.

7-8A at 24V is very impressive, 2KW @220V is a decent hair-dryer (ok, runs fulltime and is less noisy...)
Surely on any planning 40-45ft craft with twin engines alternators would cope, and it wouldn't be difficult to get a scale down version of Bart's setup and run it of a decent 400-500Ah bank of batteries through inverters.

OK, who's first?

JTB, that should finish off your refit nicely I recon!

cheers

V.

this is is a game changer for small boats;Fins have so many disadvantages in the shallow water of canals and up against a harbour walls. I'm guessing they can also get jammed with ropes and seaweed as well.

a small self contained gyro makes sense; it will probably be £29k not $29k by the time it gets over from the states.

 

[rustybarge]

Just realised it has two inputs....

15 amps 12v dc for the control circuitry, and 2kw at 110-230 v ac for spinning the gyro.

how many amps is that at 12v dc combined?

 

[jrudge]

Bear in mind that the headline price is only part of the equasion ( having looked in to this in depth!).

There is the unit, transport form the USA, VAT and fitting. Fitting requires a cradle, a bunch of bits and normally a heap of labour.

In my case a Seakeeper 9 is USD 66,900 but the bill would have been £72,000 + VAT.

 

[BruceK]

Just seen the vid on the sports fisher application. That's impressive! Too bad I can't afford one

 

[rustybarge]

Bear in mind that the headline price is only part of the equasion ( having looked in to this in depth!).

There is the unit, transport form the USA, VAT and fitting. Fitting requires a cradle, a bunch of bits and normally a heap of labour.

In my case a Seakeeper 9 is USD 66,900 but the bill would have been £72,000 + VAT.

That $67k is about £45k, plus another £27k import and fitting, plus vat. That makes £86.5k total. Call it double the the basic price of the gyro!!!

So....

$29k is £20k, doubling that would give you the approx 'ball park ' cost installed.

 

[MapisM]

Just realised it has two inputs....
15 amps 12v dc for the control circuitry, and 2kw at 110-230 v ac for spinning the gyro.
how many amps is that at 12v dc combined?

LOL, were you thrown out also of A level electrical class, by chance?
There isn't a such thing as a mathematical answer to your question - just google for power factor (which is the missing number here), if you would like to dig into more details.
But if, as I would guess, it's just a ballpark figure that you are after, it's bound to be within 300A or so.

 

[jfm]

... up against a harbour walls. I'm guessing they can also get jammed with ropes and seaweed as well.

Seaweed is a non issue unless you also have that problem lots with your rudders. Jamming ropes happens once, then you learn With harbour walls, you can limit the outswing angle or just run the outboard one. You don't berth against a wall with a big onshore swell anyway, for obvious reasons. I agree this new small seakeeepr sounds like an excellent thing for smaller boats

15 amps 12v dc for the control circuitry, and 2kw at 110-230 v ac for spinning the gyro.

how many amps is that at 12v dc combined?
Read more at http://www.ybw.com/forums/showthrea...-for-small-boats-launched#o67ZALsw3OSL0qmV.99

That's around 2.5kw all in, so you'd expect a 3Kw inverter would be fine. Ballpark 200 amps at 12v DC and 100Amps at 24v DC. BUT I suspect that spin motor electrical demand is during spin up - I doubt it is such a high load when up to speed.

The alternators typically fitted to say 600hp engines will be stretched doing these numbers, but you could fit bigger low-rpm alternators (like the Mastervolt ones I have that do something like 90% of max current at something tiny like 700rpm) and double belts fairly easily

 

[rustybarge]

LOL, were you thrown out also of A level electrical class, by chance?
There isn't a such thing as a mathematical answer to your question - just google for power factor (which is the missing number here), if you would like to dig into more details.
But if, as I would guess, it's just a ballpark figure that you are after, it's bound to be within 300A or so.

Thanks. That's quite a bit of juice to supply over a day.

 

[rustybarge]

Seaweed is a non issue unless you also have that problem lots with your rudders. Jamming ropes happens once, then you learn With harbour walls, you can limit the outswing angle or just run the outboard one. You don't berth against a wall with a big onshore swell anyway, for obvious reasons. I agree this new small seakeeepr sounds like an excellent thing for smaller boats

That's around 2.5kw all in, so you'd expect a 3Kw inverter would be fine. Ballpark 200 amps at 12v DC and 100Amps at 24v DC. BUT I suspect that spin motor electrical demand is during spin up - I doubt it is such a high load when up to speed.

The alternators typically fitted to say 600hp engines will be stretched doing these numbers, but you could fit bigger low-rpm alternators (like the Mastervolt ones I have that do something like 90% of max current at something tiny like 700rpm) and double belts fairly easily

Although Running the gyro load directly off the hi-output alternators underway would leave very little capacity to charge the batteries, perhaps it might make sense to design the whole system around the genny?

 

[mlines]

I am not in the market for these but I am interested in whether they make the boat harder to steer. The same gyroscopic effect that reduces roll sure makes it harder to steer?

Martin

 

[jfm]

I am not in the market for these but I am interested in whether they make the boat harder to steer. The same gyroscopic effect that reduces roll sure makes it harder to steer?

Martin

Absolutely not. The gyro is gimballed athwartships and spins on a vertical axis, so it can only exert a "twisting" force on the boat about the boat's fore-aft axis. It therefore has no material effect on steering

 

[jfm]

Although Running the gyro load directly off the hi-output alternators underway would leave very little capacity to charge the batteries, perhaps it might make sense to design the whole system around the genny?

I think you're steeped in a world of crummy alternators. With an installation like this it makes sense to install decent alternators. There are plenty but here is an example (I have these, in lieu of standard Caterpillar alternators) http://www.cactusnav.com/mastervolt-alternator-24150-incl-3stage-charge-regulator-p-14245.html

These are nominal 150 amps each @24volts, 3.5Kw, so with a pair of them you don't even have to think abut this gyro nor contemplate starting a genset underway. Furthermore they develop high charge current at low RPM (that is their party trick, in fact). Eg 100amps @2000rpm, which with a 2-1 pulley means just 1000rpm at the engine, which is D speed. So a pair of these at D speed powers the gyro, even in spin up mode, and charges your batteries and runs your house load on any size boat that you'd have this gyro in. The full 150 amps comes at 3800 rpm, =engine speed of 1900, ie D speed. You could fit a 3-1 pulley of course: with a 300hp++ engine you have plenty of reserve because these things are taking 8hp or so (each) off the engine

 

[rustybarge]

I think you're steeped in a world of crummy alternators. With an installation like this it makes sense to install decent alternators. There are plenty but here is an example (I have these, in lieu of standard Caterpillar alternators) http://www.cactusnav.com/mastervolt-alternator-24150-incl-3stage-charge-regulator-p-14245.html

These are nominal 150 amps each @24volts, 3.5Kw, so with a pair of them you don't even have to think abut this gyro nor contemplate starting a genset underway. Furthermore they develop high charge current at low RPM (that is their party trick, in fact). Eg 100amps @2000rpm, which with a 2-1 pulley means just 1000rpm at the engine, which is D speed. So a pair of these at D speed powers the gyro, even in spin up mode, and charges your batteries and runs your house load on any size boat that you'd have this gyro in. The full 150 amps comes at 3800 rpm, =engine speed of 1900, ie D speed. You could fit a 3-1 pulley of course: with a 300hp++ engine you have plenty of reserve because these things are taking 8hp or so (each) off the engine

Those alternators look like the dogs ....! I never knew you could get a built in 3 stage charger as well.

...ain't cheap at £1700 each. IMO better to use standard alternators and put the extra £3400 towards a nice slow running onan or NL genny that could work the air/c as well.

 

[grumpy_o_g]

Those alternators look like the dogs ....! I never knew you could get a built in 3 stage charger as well.

...ain't cheap at £1700 each. IMO better to use standard alternators and put the extra £3400 towards a nice slow running onan or NL genny that could work the air/c as well.

Balmer (very popular with raggies) might be a little cheaper - I'd think you would be looking at a lot less than a grand for 150A alternators based on the prices of their 90A and 110A bolt-on replacements aimed at yachts that want to charge at low rpm preferably. Generally regarded as good quality too. Going back a few years a 110A cost a few hundred at most. Remember that wiring may well need beefing up too if you upgrade alternators.