Boat in build pics (2013 Fairline Squadron 78)

[rafiki_]

Yup - if we could get even 15bhp from a non reciprocating engine that would be fantastic for overnighting.
Hmmm. I wonder how small a (diesel burning) gas turbine+gearbox+alternator you can buy...

I'm not aware of anything this small, but will put out some feelers. The Torotrak transmission might be suitable, but needs the right engine. Jaguar were considering a pair of turbines for the CX75 at one stage, but I think military drones might be s source too. Who do you know in the Pentagon JFM?

 

[Deleted User YDKXO]

With Onan at least, it is dead easy to wire an additional start-stop switch. They will sell you a kit or you can diy it

Applying some logic to this, if it gets too hot in your cabin but you're still asleep, you don't care anyway so there's no real need for an auto start to fire up the gennie. Its when you wake up because its too hot that you want a/c and if you wake up, you can manually start the gennie. The problem is being too idle to get out of bed to do it so the solution is, as you say, a remote gennie start switch. So I've just ordered one for my Kohler. Looks like £100 well spent. And I get to put it on my side of the bed unlike the A/C control which is on SWMBO's side

 

[scubaman]

Sorry for the slight off topic and this may have been covered already elsewhere, but:

AFAIK, none of the builders add any thermal insulation to their boats, probably to save weight and cost.

However, this would seem an easy task at the build phase and there would seem to be plenty of room for adding a light layer of insulation. This would probably not add to usability in bigger boats, where there is room for enough genny -capacity to feed all the air-con needed, but it might make sense in smaller boats where 'oversized' gennies add a lot of weight and take up room?

Insulation would be beneficial both in colder and hotter climates and of course it would help save energy (fuel) in all sizes of boats?

 

[prv]

Applying some logic to this, if it gets too hot in your cabin but you're still asleep, you don't care anyway so there's no real need for an auto start to fire up the gennie. Its when you wake up because its too hot that you want a/c and if you wake up, you can manually start the gennie.

Applying slightly more logic, if you had an auto-start gennie and air-con system, you wouldn't wake up because it's too hot in the first place

But what do I know, the nearest I get to aircon on board is kicking the duvet off a bit

Pete

 

[jrudge]

A simple thermostat with adjustable dead band should enable you to do this, you simply have it activate one two pole or if you like two single pole relays, one fitted to the Genset so it's contact starts that and one to start the AC system in a similar way.

However, the load on the AC system will likely be less at night, so it could end up switching in/out too frequently, so chose a make-on-rise thermostat that has an adjustable differential of say 4 degrees or so, some electronic thermostats have adjustable dead bands and should suffice.

So for instance, say you normally leave your normal daytime setting on your AC set to switch-on the compressor at 23C and it cools down to switch it off at say 21.5C. When you retire, you can switch off the AC and enable your night thermostat circuit.

The internal temp rises to say 25C which activates your night t'stat starting the gennie and AC, the AC control senses the temp is much higher than its setpoint (23C) so it switches on and cools the space down to 21.5C and then switches the compressor off, but because the night t'stat has not reached its lower switch-off differential (25-4=21C) the gennie is kept running. If the temp inside falls below 21C then both Gennie and AC is held off. It will not start again unless the space rises to 25C again. Just playing with setpoints but you get my drift.

I thought the same thing... you will find that this part HONEYWELL DT90E WIRED ECO DIGITAL ROOM THERMOSTAT STAT ( £20 on ebay http://www.ebay.co.uk/itm/HONEYWELL...arden_Hearing_Cooling_Air&hash=item19d9ecdd60) does exactly this.

I bought one for exactly this reason. I have it in my pile of things to do. Electrically it is simple. Finding somewhere neat to mount it and the associated "auto" switch is actually far harder!

 

[jfm]

Sorry for the slight off topic and this may have been covered already elsewhere, but:

AFAIK, none of the builders add any thermal insulation to their boats, probably to save weight and cost.

However, this would seem an easy task at the build phase and there would seem to be plenty of room for adding a light layer of insulation. This would probably not add to usability in bigger boats, where there is room for enough genny -capacity to feed all the air-con needed, but it might make sense in smaller boats where 'oversized' gennies add a lot of weight and take up room?

Insulation would be beneficial both in colder and hotter climates and of course it would help save energy (fuel) in all sizes of boats?

In a lot of modern boats, and Fairline for sure, much of the deck and superstructure mould is cored with 20mm or so of rigid foam, so that offers some insulation. The hulls on many boats (incl fairline) are generally not cored though (Jeanneau core their hulls). On uncored areas you'd have to apply insulation boards/sheets and I'm not 100% sure I'd want it - it would be cut all different ways to fit between frames and stringers and would have to be cut around pipes and wires, plus it would remove visibility of seacocks and hull, etc. It could be done at some cost but there's quite a package of downsides you'd have to live with too

 

[Deleted User YDKXO]

Applying slightly more logic, if you had an auto-start gennie and air-con system, you wouldn't wake up because it's too hot in the first place

True!

 

[Deleted User YDKXO]

The hulls on many boats (incl fairline) are generally not cored though (Jeanneau core their hulls).

I thought it was common to core hulls but only above the waterline? It would be interesting if the boaty mags published an article on major boat builders comparing their construction methods. I don't recall ever seeing an article comparing the virtues of hand lay up v spray lay up, cored v non-cored hulls, vacuum bagging, resin infusion etc

 

[jfm]

I thought it was common to core hulls but only above the waterline? It would be interesting if the boaty mags published an article on major boat builders comparing their construction methods. I don't recall ever seeing an article comparing the virtues of hand lay up v spray lay up, cored v non-cored hulls, vacuum bagging, resin infusion etc

You may be right about widespread coring above w/line - I don't have the data. The Fairline hulls I'm familiar with are not sheet-cored even above the w/line. Actually the transoms are cored but that's more to allow them to screw parts to - if you make the transom solid then apply core material then a couple layers of light grp you can drive self tappers in nicely

A comparison of build methods as you say would be good but to be any use it needs to be done by an engineering lab not a yachtmag journalist. Then you can compare mechanical properties properly. Of course, if they compare a properly cored fibreglass panel with an uncored one of same weight the cored one will be stiffer and stronger in bending loads. The real issue is build quality, because an improperly cored hull will be worse. It's difficult to cover that in a test because to find out whether production cored hulls are properly cored requires destructive/intrusive examination

 

[Deleted User YDKXO]

A comparison of build methods as you say would be good but to be any use it needs to be done by an engineering lab not a yachtmag journalist. Then you can compare mechanical properties properly. Of course, if they compare a properly cored fibreglass panel with an uncored one of same weight the cored one will be stiffer and stronger in bending loads. The real issue is build quality, because an improperly cored hull will be worse. It's difficult to cover that in a test because to find out whether production cored hulls are properly cored requires destructive/intrusive examination

Of course you're right. I wasn't suggesting that the mags actually test hull construction methods because they wouldn't want to piss off any of their advertisers anyway. I just think there's a lot of ignorance on the part of boat buyers about what they are buying and possibly some more comparative information in boaty mags would lead buyers to carry out more research into what they're actually buying

 

[petem]

A comparison of build methods as you say would be good but to be any use it needs to be done by an engineering lab not a yachtmag journalist.

Good for who, you? Rather a disparaging comment isn't it?!?! For most of us mere mortals a journo might be perfectly equipped to explain the basics in a way that an expert may not be able to.

 

[vas]

Sorry for the slight off topic and this may have been covered already elsewhere, but:

AFAIK, none of the builders add any thermal insulation to their boats, probably to save weight and cost.

However, this would seem an easy task at the build phase and there would seem to be plenty of room for adding a light layer of insulation. This would probably not add to usability in bigger boats, where there is room for enough genny -capacity to feed all the air-con needed, but it might make sense in smaller boats where 'oversized' gennies add a lot of weight and take up room?

Insulation would be beneficial both in colder and hotter climates and of course it would help save energy (fuel) in all sizes of boats?

having discussed this issue with a colleague who's speciallisation is HVAC and shading, he recons that a combination of 30-40mm of insulation on the decks/topsides together with a reflective membrane is the only thing you need for cutting down the heat loads. Mine has 30mm white polywhatever and it's still bleeding hot in there when stationary/marina based. He recons I can reduce temps by 4-5C by this reflective sheeting. Problem is how toget it on (my deck is ply on iroko frames that are 250-300mm apart and all this zig-zag is a bit too much to handle.)

Further, for the summer heat, I wouldn't like a cored below w/l hull as the sea temp would be a nice means of heat dissipation

Also true that I definitely wouldn't like a loose/glued on layer of insulation on the inside either...

Decent windows large openings, good airflow (open doors/no privacy!, mosquito nets, etc) is imho the solution.


V.

 

[rafiki_]

Of course you're right. I wasn't suggesting that the mags actually test hull construction methods because they wouldn't want to piss off any of their advertisers anyway. I just think there's a lot of ignorance on the part of boat buyers about what they are buying and possibly some more comparative information in boaty mags would lead buyers to carry out more research into what they're actually buying

Do you really think the majority of boat buyers would look into this level of information? You 2 guys might, but I'm not convinced that the majority of buyers would be able to make a sensible judgement about what is right/wrong, better/worse. I think people buy more on specification, value, style and personal choice. I dont think anyone selects an Audi A8 over a Bimmer 7 series because the Audi has a alu body. I also don't think anyone would select an Audi over a Jag XJ because the one is bonded, and the other rivetted, despite them both being aluminium.
As an Engineer, I would be very interested in hearing about different build processes, and the reasons behind them, but not sure it would really sway my choice, unless I felt one build process was a disaster waiting to happen, but this is more likely to be reflected in the residual value, which I wuld definitely be interested in before a purchase.

 

[halcyon]

Yup - if we could get even 15bhp from a non reciprocating engine that would be fantastic for overnighting.
Hmmm. I wonder how small a (diesel burning) gas turbine+gearbox+alternator you can buy...

Rover made them in 1955 see http://www.flightglobal.com/pdfarchive/view/1955/1955 - 0701.html, this was aircraft, but they made portable as well.

We were there once.

I sometime wonder about two or three gas turbines driving alternators, then use electric propulsion. You have silent smoth power for propulsion, and power station for domestic power that burn nearly anything.

Brian

 

[scubaman]

Just one further comment on the insulation.

In theory, the spaces between stringers on the sides could be filled with insulation without it being in the way of anything important. The bottom could do without any, as a big part of the heat/cold comes from the outside surfaces.

An added bonus could be a slightly quieter hull as it could absorb at least some of the higher frequency noises (ie. water generated noises both under way and at rest). Don't know how much difference it would make at the end of the day, but at the moment keeping the boat warm in the autumn requires a heater powerful enough to heat a house in the winter. Basically it's the same trying to keep the boat cool in the med.

 

[rafiki_]

Wouldn't any insulation in the hull become waterlogged with foul smelling bilge water over time? You would never be able to dry it surely? I like the idea of Vas's reflective material, but this might become a bit of a pain if all med boats were mirrored? An alternative would be to use infer red resistant paint, like the army uses. This is surprising good at resisting the temp increase due to solar loading. Again, might not look so good on a Sq 78.

 

[scubaman]

Wouldn't any insulation in the hull become waterlogged with foul smelling bilge water over time? You would never be able to dry it surely?

Not if you only put it to side walls and perhaps ceilings of the superstructure, where possible.

Agree on the paint, although it might become the next big hit. Just look at some of the super cars with their matt finishes...

 

[jfm]

might become a bit of a pain if all med boats were mirrored?

Scubaman, yup you are right and maybe this needs more thought. Rafiki, I assumed Vas's reflective material would be hidden below the decks and above the ceiling liners, not on show. But I might be worng on that. It would be better if on show on the deck, but will work to a degree if stuck below the deck. Same with paint. The insul wouldn't get waterlogged if it was closed cell foam

 

[vas]

Scubaman, yup you are right and maybe this needs more thought. Rafiki, I assumed Vas's reflective material would be hidden below the decks and above the ceiling liners, not on show. But I might be worng on that. It would be better if on show on the deck, but will work to a degree if stuck below the deck. Same with paint. The insul wouldn't get waterlogged if it was closed cell foam

spot on J,

the idea is that UNDERNEATH the skin (be it deck/sundeck/whatever) you place this thin film (bit like aluminum foil that you use in the kitchen only thinner and much stronger) and under it the insulation.
Obviously not visible, just reflects the heat back to the deck (means the deck is slightly warmer/hotter than without the film.
Film costs peanuts, you can also get it bonded onto an insulation slab (presumably to cut the costs of fitting it)

I'll do it on mine, but need the dust to settle and getting into the clean assembly mode (give me some time )

Reflective paints is another way, but imho the industry hasn't yet produced something with tangible advantages.
Hm, now that I typed it, the colleague I mentioned before, last year completed a research project measuring the performance of an insulating paint featuring nanospheres of something rather (by a Greek manufacturer). I'll ask him and come back to you.

cheers

V.

 

[benjenbav]

Scubaman, yup you are right and maybe this needs more thought. Rafiki, I assumed Vas's reflective material would be hidden below the decks and above the ceiling liners, not on show. But I might be worng on that. It would be better if on show on the deck, but will work to a degree if stuck below the deck. Same with paint. The insul wouldn't get waterlogged if it was closed cell foam

Thing is, if you sort the temperature out completely without running the a/c all night your nubile nymphs won't be glistening and writhing under the 3,000 thread count egyptian cotton sheets and there where will you be?

It'd drag Match 2's OB rating into the gutter.