Anders_P42
Member
Some info here on Seakeeper 5 install, including vid. Looks like it works a treat.
http://prnautica.com/seakeeper-sk5-on-a-princess-p43/
http://prnautica.com/seakeeper-sk5-on-a-princess-p43/
Princess 43
- Thread starter Magnum
- Start date
Magnum
RIP
Does anyone know if this article has been published yet? Keen to get some feedback before SIBS.
D
Deleted User YDKXO
Guest
Was it not in last month's MBY? I'm not sure it added much to the general font of knowledge about stabs as they seemed to choose a flat calm day to test it but IIRC it did highlight another advantage of stabs in terms of damping the motion of the boat during steering manoeuvres. Happy to scan the article and email it to you if you want. I guess I shouldn't say that
Anders_P42
Member
The link I posted above shows video and graphs of roll with/without gyro locked.
Magnum
RIP
Thanks Anders, I saw that. I was looking for an independent review that discussed the pros and cons.
jfm
Well-known member
Hi Magnum. It's really hard to get a properly good review of these things. The physics is pretty complex and so many reviews contain a degree of bllx. But still, you can be very confident a gyro will make a material benefit to the princess 43 at anchor, and some benefit underway, but don't expect miracles
The Dave Marsh article in MBY seems to imply that all the manufacturers have to do is make a small gyro for small boats. It's way more complex that that. A small boat has a much shorter roll period than a large boat, so when a big and a small boat are beside each other in same anchorage the big one might be rolling at 2x the roll period of the smaller one (i.e. at half the angular speed)
Therefore to stabilise a 1/2x size boat you cannot just fit 1/2 x size of gyro and expect same result. The gyro has to precess faster (which means the hydraulics that control the precession have to work faster, which is an engineering challenge) and while the boat might weigh half as much it is rotating (rolling) faster so its angular momentum can be more than 1/2 that of the larger boat. (though, there is a square law applicable to distance of mass from roll centre, so it all depends on design of boat). End result is that stabilising small boats is no walk in the park
Now, the Seakeeper product is very impressive stuff indeed (understatement) and I'm highly confident their gyro y will do a great job at anchor even with these constraints, so I'd definitely support anyone speccing one for a p43, but do not expect miracles
Underway, any given waves and their periods are bigger relative to a small boat than to a large boat. AOTBE a gyro-ed small boat will get less stabilisation benefit than a finned small boat, and the gyro/fin difference out to be bigger than for a larger boat. The limitation on gyro stabilisation underway is that the gyro precesses only so far then has to hit the stops and thus cease to offer any anti-roll torque, whereas fins can be held at an angle all day. With gyros underway, you can have a lot of stabilisation torque for a small interval of time, or vice versa, but not both. With fins you can have both. My hunch therefore is that you will find the gyro of some benefit but not miraculous underway. However afaik there are no fins available for p43 right now (there will be soonish), so you are where you are, and the gyro is still worth having in my book
Remember also that the gyro isn't there just for big seas underway. Even if you go out in calm seas it is great to remove the small amount of roll that you'd otherwise get. Reduces seasickness, makes for easier cups of tea and just all round comfort. I run my stabs even in very calm weather and they justify their existence even in those conditions imho
The Dave Marsh article in MBY seems to imply that all the manufacturers have to do is make a small gyro for small boats. It's way more complex that that. A small boat has a much shorter roll period than a large boat, so when a big and a small boat are beside each other in same anchorage the big one might be rolling at 2x the roll period of the smaller one (i.e. at half the angular speed)
Therefore to stabilise a 1/2x size boat you cannot just fit 1/2 x size of gyro and expect same result. The gyro has to precess faster (which means the hydraulics that control the precession have to work faster, which is an engineering challenge) and while the boat might weigh half as much it is rotating (rolling) faster so its angular momentum can be more than 1/2 that of the larger boat. (though, there is a square law applicable to distance of mass from roll centre, so it all depends on design of boat). End result is that stabilising small boats is no walk in the park
Now, the Seakeeper product is very impressive stuff indeed (understatement) and I'm highly confident their gyro y will do a great job at anchor even with these constraints, so I'd definitely support anyone speccing one for a p43, but do not expect miracles
Underway, any given waves and their periods are bigger relative to a small boat than to a large boat. AOTBE a gyro-ed small boat will get less stabilisation benefit than a finned small boat, and the gyro/fin difference out to be bigger than for a larger boat. The limitation on gyro stabilisation underway is that the gyro precesses only so far then has to hit the stops and thus cease to offer any anti-roll torque, whereas fins can be held at an angle all day. With gyros underway, you can have a lot of stabilisation torque for a small interval of time, or vice versa, but not both. With fins you can have both. My hunch therefore is that you will find the gyro of some benefit but not miraculous underway. However afaik there are no fins available for p43 right now (there will be soonish), so you are where you are, and the gyro is still worth having in my book
Remember also that the gyro isn't there just for big seas underway. Even if you go out in calm seas it is great to remove the small amount of roll that you'd otherwise get. Reduces seasickness, makes for easier cups of tea and just all round comfort. I run my stabs even in very calm weather and they justify their existence even in those conditions imho
Magnum
RIP
Thanks jfm That all makes sense. Personally I'm only really bothered about performance at anchor.
Princess are telling me the price quoted in the MBY article is incorrect and have quoted £39, 650 ex VAT for the Seakeeper 5 fitted in-build. Tht's not an inconsiderable sum for a boat of this value and quite a bit more than the US RRP of $29,000. They are checking the quoted price ...
That all makes sense. Personally I'm only really bothered about performance at anchor.Princess are telling me the price quoted in the MBY article is incorrect and have quoted £39, 650 ex VAT for the Seakeeper 5 fitted in-build. Tht's not an inconsiderable sum for a boat of this value and quite a bit more than the US RRP of $29,000. They are checking the quoted price ...
benjenbav
Well-known member
Thanks jfm
Princess are telling me the price quoted in the MBY article is incorrect and have quoted £39, 650 ex VAT for the Seakeeper 5 fitted in-build. Tht's not an inconsiderable sum for a boat of this value and quite a bit more than the US RRP of $29,000. They are checking the quoted price ...
Haven't got the article in front on me but recall being surprised by how much of the total figure was made up from fitting costs which I would have thought should be quite modest: Bolt down unit. Attach power.
Maybe the cost is in sourcing the bolts instead of using self-tappers as per usual?
Magnum
RIP
Haven't got the article in front on me but recall being surprised by how much of the total figure was made up from fitting costs which I would have thought should be quite modest: Bolt down unit. Attach power.
Maybe the cost is in sourcing the bolts instead of using self-tappers as per usual?
The article quoted 250 hours installation time but said that "installing it during the build should be substantially quicker and cheaper".
D
Deleted User YDKXO
Guest
Sounds like somebody in the costing dept has just taken the purchase cost of the unit, stuck his finger in the air and said let's double the price just to be on the safe side because we don't really know how much these things cost to install. I'm with bjb on this. Even as a retrofit, 250hrs to fit the thing sounds ridiculous. Thats 3 weeks for 2 blokes. All it consists off is a bit of extra grp work, bolt the thing down and connect up the power. As an OEM fitment I would say 3 days for 2 blokes max plus a bit of CAD design work. Call it £25k + VAT to leave a bit of a margin for the manufacturer and dealer, not forgetting that undoubtedly the manufacturer will get an OEM discount out of Seakeeper
rafiki_
Well-known member
Normal translation from US$ price to UK£ is 1:1, ie $29,000 = £29,000. Don't really understand why, other than VAT is considerably more than US Fed + local taxes. I would have thought a fair quote would be £34,000 ish, a couple of £k to fit and an additional 10% margin.
D
Deleted User YDKXO
Guest
The manufacturer would be able to reclaim any VAT on importation. Note that the selling price is also ex VAT at £39650 + VAT so VAT should not factor in the price calcs anywhere. On the other hand, there will be shipping costs to the UK plus, possibly, some duties to pay but as I said, I bet that Princess will get an OEM discount which will more than compensate for those 2 costs
Anders_P42
Member
Installation guide here, some electrics and pluming to do but drop in if they design mounts in to boat.
http://www.seakeeper.com/uploads/do...45-5_SEAKEEPER_5_GYRO_INSTALLATION_MANUAL.pdf
http://www.seakeeper.com/uploads/do...45-5_SEAKEEPER_5_GYRO_INSTALLATION_MANUAL.pdf
Magnum
RIP
Just received a quote from PR Nautica. Retrofit cost is £33,450 + VAT.
jimmy_the_builder
Well-known member
Where is it retro'd - lazarette? If so - is there a compromise available where you source the gyro, then simply get Princess to drop it into the laz before the deck moulding is fitted, and then have the rest of the install work done later?
D
Deleted User YDKXO
Guest
The only problem with that is that Princess are going to deny any warranty responsibility if they can vaguely blame any other problem on the installation. If Magnum got Princess to drop their price by say 10-15%, which IMHO is perfectly feasible, then their price is close enough to the retrofit price not to make it worth bothering with the retrofit and Magnum gets to sleep at night. I still think that £33k is over the top as well
Anders_P42
Member
Worth asking Osmotech for a quote too.
Magnum
RIP
A very productive day at SIBS today talking to Princess, Cummins, Raymarine and Seakeeper regarding the specification of my boat. For those that are interested I've decided to make a couple of additions to the specification.
Firstly, a Seakeeper SK5 gyro. I think it's hard to argue against the benefits this will bring to our time at anchor. The only downside - as with most really good things - is cost. It will be fitted by Princess during the build which avoids the 10 day retrofit time and hopefully result in a cleaner install.
Secondly, I'll be having Raymarine eS128 MFDs in lieu of the optional e128 units. The eS units look sharper, have pinch-to-zoom and built in CHIRP sonar.
Thirdly, Princess have agreed to fit (at extra cost) a Miele KM6115 4 ring induction hob instead of the optional Ceramic 3-ring hob (thanks jfm )
Finally, although I hate maintaining teak the absence of it on the flybridge makes it uncomfortably bright, so teak it is.
That was the easy bit. Have you seen the thickness of Princess's fabric books?
Firstly, a Seakeeper SK5 gyro. I think it's hard to argue against the benefits this will bring to our time at anchor. The only downside - as with most really good things - is cost. It will be fitted by Princess during the build which avoids the 10 day retrofit time and hopefully result in a cleaner install.
Secondly, I'll be having Raymarine eS128 MFDs in lieu of the optional e128 units. The eS units look sharper, have pinch-to-zoom and built in CHIRP sonar.
Thirdly, Princess have agreed to fit (at extra cost) a Miele KM6115 4 ring induction hob instead of the optional Ceramic 3-ring hob (thanks jfm
)Finally, although I hate maintaining teak the absence of it on the flybridge makes it uncomfortably bright, so teak it is.
That was the easy bit. Have you seen the thickness of Princess's fabric books?
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pks1702
Well-known member
No spec for Scatter Cushions mentioned.......
I am sure an expert will be along soon
I am sure an expert will be along soon
MapisM
Well-known member
Great specs for what will surely be a great boat!
But...
In your boots, I'd rather use sunglasses...
More seriously, on the f/b particularly, I've yet to find anyone regretting to NOT have specced teak, while I heard several folks regretting the opposite.
Hurricane being one example, IIRC - and he has a Princess, too...
But...
...I have to say that this is the weirdest reason I've ever heard for glueing some wood above a perfectly good GRP surface (and pay for that, too!).
In your boots, I'd rather use sunglasses...
More seriously, on the f/b particularly, I've yet to find anyone regretting to NOT have specced teak, while I heard several folks regretting the opposite.
Hurricane being one example, IIRC - and he has a Princess, too...
