Ideal Generator?

[TeddyDiver]

Originally Posted by Dockhead

I think we need your 'shine recipe

50liters of water
8kg of sugar
1kg lemons
Currant leaves
100g of yeast

Boil the water on induction cooktop and ad the sugar
After cooling pour it into big glass tank (a big bottle) and ad the rest of ingredients
Put a water lock on the tank.
Keep it in a warm place and enjoy the view and cosy sound of the water lock

Tell me when fermentation slows down. Hope you have iron bottom pot. It doesn't work on the induction cooktop without

BR Teddy

ps. By the way, induction works best becouse of the precise temperature control

[Pete7]

Originally Posted by Dockhead

But there was a terrible gas explosion some years ago in Poole Harbour on board a Royal Navy training yacht using the absolute best possible practices. The cadets even pumped out the dry bilges with a manual bilge pump as an extra precaution to get any lingering gas out (anyone on here do that?). A cadet lost a leg (IIRC).

So it is impossible to make a gas system on a boat 100% safe.

If there's no choice, then no reason to worry about it -- just make it as safe as possible. But if you do have a choice -- why take the risk? I hate having gas on board.

Indeed, paragraph 1.6 give the details of pumping an empty bilge after any water has been removed to reduce the possibility of gas building up. I certainly remember doing this on all MOD service yachts we sailed.

https://assets.digital.cabinet-offic..._trenchard.pdf

[DotDun]

Originally Posted by Dockhead

.....
So it is impossible to make a gas system on a boat 100% safe.

If there's no choice, then no reason to worry about it -- just make it as safe as possible. But if you do have a choice -- why take the risk? I hate having gas on board.

I believe you meant to say "So it is impossible to make gas systems safe on 100% of boats."

A properly installed/maintained/used system is safe.

[Dockhead]

Originally Posted by DotDun

I believe you meant to say "So it is impossible to make gas systems safe on 100% of boats."

A properly installed/maintained/used system is safe.

Actually, not.

My point was that even the Royal Navy -- who are far more careful than we are -- can't make it 100% safe. Or even 99% safe.


To put it into perspective, however, of course nothing in the world is 100% safe, and we take all kinds of risks, every day, and every hour. Having gas on board is certainly not the biggest risk I take Two weeks ago, I was riding a motocross bike in the Malaysian jungle, and riding it hard. I flew off twice. I am no stranger to risk.

But I like to get some fun or some other reward out of taking the various risks I take. Gas on board seems to me to be simply an unnecessary, and an unreasonable risk. For a boat decently supplied with electrical power, anyway.

[StuM]

Originally Posted by a64pilot

DotDun,
Help me out, rough calculations have it taking 27 AH to raise one gallon of water from 70F to 212F to make it begin to boil, is that correct?

I got there by 212 - 70 = 142 degrees x 8.33 = 1183 BTU
1183 BTU is .346 KWH or 346 WHR ? if you have a 13V bank, that's 26.6 AH?

Doing it in proper units

70F = 21C so we need to raise it 79C
I gal = 3.785l = 3.785Kg

So we need 3.785 x 79 = 299.3 Kcalories
(Call it 300).

1Kcal = 1.162 Wh

So we need 347.8 Wh = 26.75A @ 13V.
Yep, close enough give the precision of the conversion factors

[DotDun]

Originally Posted by Dockhead

Actually, not.

My point was that even the Royal Navy -- who are far more careful than we are -- can't make it 100% safe. Or even 99% safe.


To put it into perspective, however, of course nothing in the world is 100% safe, and we take all kinds of risks, every day, and every hour. Having gas on board is certainly not the biggest risk I take Two weeks ago, I was riding a motocross bike in the Malaysian jungle, and riding it hard. I flew off twice. I am no stranger to risk.

But I like to get some fun or some other reward out of taking the various risks I take. Gas on board seems to me to be simply an unnecessary, and an unreasonable risk. For a boat decently supplied with electrical power, anyway.

My point is there are a lot of boats floating with propane on board. For those boats, it must be 100% safe. The danger of propane in the context you are talking is binary, it's either safe or it's not. No partially safe!

Yes, it's yet another boat system that not only needs proper design, but it also requires vigilance to make sure it stays safe. Propane sniffers and auto shutoffs are wonderful devices, and they need tested periodically.

For a 100% safe boat, one must remove all the knives and scissors, not just the propane!

[mcarling]

Originally Posted by DotDun

My point is there are a lot of boats floating with propane on board. For those boats, it must be 100% safe. The danger of propane in the context you are talking is binary, it's either safe or it's not. No partially safe!

By that logic, every boat with propane onboard is 100% safe the day before a propane explosion and 100% unsafe only on the day of the explosion.

[sailorchic34]

Originally Posted by DotDun

My point is there are a lot of boats floating with propane on board. For those boats, it must be 100% safe. The danger of propane in the context you are talking is binary, it's either safe or it's not. No partially safe!

Yes, it's yet another boat system that not only needs proper design, but it also requires vigilance to make sure it stays safe. Propane sniffers and auto shutoffs are wonderful devices, and they need tested periodically.

For a 100% safe boat, one must remove all the knives and scissors, not just the propane!

Actually boats burn up all the time, well many times a year, due to a propane failure. It does not happen a lot, but it does happen. It's more like 95% safe per year. As gas regulators age, they can lock up or it's diaphram rip. or a hose leaks at a fitting or valve leak at the range. I also suspect not all propane solenoids hold close spring is rated for 120 psig. Under normal conditions the solenoid only sees about 1/4 psig 11 inches water column anyway. A tad more then 1/4 psig. If the regulator locks up, you can easily have 120+ psig at the solenoid valve inlet.

Properly designed and installed, a propane is close to 100% safe when New. 10 or 20 years later, its less safe, year after year.

Which reminds me to replace the old propane hose (I have the new one already), one of these days.

Question is when was the last time folks tested their solenoids to make sure they still seal shut 100%. I suspect it does not happen that often. Even I only check it every year or so.

[Hobie_ind]

Originally Posted by Dockhead

Actually, not.

My point was that even the Royal Navy -- who are far more careful than we are -- can't make it 100% safe. Or even 99% safe.


To put it into perspective, however, of course nothing in the world is 100% safe, and we take all kinds of risks, every day, and every hour. Having gas on board is certainly not the biggest risk I take Two weeks ago, I was riding a motocross bike in the Malaysian jungle, and riding it hard. I flew off twice. I am no stranger to risk.

But I like to get some fun or some other reward out of taking the various risks I take. Gas on board seems to me to be simply an unnecessary, and an unreasonable risk. For a boat decently supplied with electrical power, anyway.

There are risks and some logistical issues with gas, but it's simplicity is tough to beat. Having a gauge installed at the tank allows checking system integrity (isolate the tanks and confirm the pressure doesn't bleed off overnight) and the primary components are relatively cheap to just replace on a regular preventative maintenance cycle.

I like the idea of not having a gas system, but for the cruising we do I'm not willing to have an electric stove/oven that effectively makes the generator a 'mission critical' piece of equipment.

Some friends of ours have had to change their plans multiple times over the past year as they've battled with a temperamental generator. I think they're almost at the point of 'biting the bullet' and dropping a new one in its place so they don't miss the upcoming window for their South Pacific crossing. 5+ years of full time cruising with a fully electric boat really racks up the hours on a generator and reliability starts to degrade with each hour.

For me, flexibility fits on the reward side of the risk/reward equation, but that's a very different and personal analysis for every cruiser.

PS...In the interest of full disclosure, we carry a two burner electric stove as a backup to the gas system in the event we ran out or had an issue with the system. We also have a microwave........I do like redundancy!

[carstenb]

Originally Posted by StuM

Doing it in proper units

70F = 21C so we need to raise it 79C
I gal = 3.785l = 3.785Kg

So we need 3.785 x 79 = 299.3 Kcalories
(Call it 300).

1Kcal = 1.162 Wh

So we need 347.8 Wh = 26.75A @ 13V.
Yep, close enough give the precision of the conversion factors

Stu/Pilot - back when I used t design hydraulic sytems, for a quick and dirty answer we used 15 or 20% as an add on factor for volumetric and mechanical inefficiencies.

I suspect if you add 15-20% to you 27A, you be very close to reality

[Dockhead]

Originally Posted by Hobie_ind

There are risks and some logistical issues with gas, but it's simplicity is tough to beat. Having a gauge installed at the tank allows checking system integrity (isolate the tanks and confirm the pressure doesn't bleed off overnight) and the primary components are relatively cheap to just replace on a regular preventative maintenance cycle.

I like the idea of not having a gas system, but for the cruising we do I'm not willing to have an electric stove/oven that effectively makes the generator a 'mission critical' piece of equipment.

Some friends of ours have had to change their plans multiple times over the past year as they've battled with a temperamental generator. I think they're almost at the point of 'biting the bullet' and dropping a new one in its place so they don't miss the upcoming window for their South Pacific crossing. 5+ years of full time cruising with a fully electric boat really racks up the hours on a generator and reliability starts to degrade with each hour.

For me, flexibility fits on the reward side of the risk/reward equation, but that's a very different and personal analysis for every cruiser.

PS...In the interest of full disclosure, we carry a two burner electric stove as a backup to the gas system in the event we ran out or had an issue with the system. We also have a microwave........I do like redundancy!

This is an intelligent comment on the system architecture issues which were the original subject of this thread, and brings us back to the original theme.

A third and important advantage of gas, which I should have mentioned, is this -- there is not anything which can go wrong with the system (OTHER THAN RUNNING OUT OF GAS ) which can't be fixed with a crescent wrench and a small box of spares.

The boat I am aiming for should be capable of operating autonomously for months at a time, and as much as possible to never need professional service. This goal is almost equally valid for normal coastal cruising, considering how much it spoils any cruise to be stuck somewhere looking for parts or specialized service.

One good approach to this -- what concerns energy on board -- is to concentrate on the most reliable source of electrical power -- solar -- and reduce any loads which would be dependent on generators, be modest everywhere in the use of electrical power, and diversify away from electrical power where possible. This is like my father's boat. Gas is a key element in this approach, which is a perfectly valid one.

OR, you can on the contrary concentrate all your energy needs into electrical power (even propulsion, which I won't do, but that is the logical continuation of this idea), and then make that system as robust, reliable, and serviceable as possible.

That is exactly the approach I am working on, and a very simple, very field serviceable generator based on a reliable marine propulsion engine and simple, reliable, cheap, and highly field serviceable school bus alternators -- seems like a really good way to get there. Backed up by alternators on the main engine which are fully capable of powering the boat.

[Dockhead]

Originally Posted by DotDun

My point is there are a lot of boats floating with propane on board. For those boats, it must be 100% safe. The danger of propane in the context you are talking is binary, it's either safe or it's not. No partially safe!

This confuses risks with outcomes, which are totally different things. Unless you have a time machine. That is not how risk works. Using the same logic, jumping off the Golden Gate Bridge is "100% safe" -- if by chance you happen to survive it.

[NorthernIsland]

Originally Posted by StuM

Doing it in proper units

70F = 21C so we need to raise it 79C
I gal = 3.785l = 3.785Kg

So we need 3.785 x 79 = 299.3 Kcalories
(Call it 300).

1Kcal = 1.162 Wh

So we need 347.8 Wh = 26.75A @ 13V.
Yep, close enough give the precision of the conversion factors

With 26.75A it takes 1 hour to boil.

Sent from my HTC VLE_U using Cruisers Sailing Forum mobile app

[valhalla360]

Originally Posted by NorthernIsland

With 26.75A it takes 1 hour to boil.

Sent from my HTC VLE_U using Cruisers Sailing Forum mobile app

Ouch.

(though I'm sure Stu will admit his error unlike some)

[valhalla360]

The risk discussion is rather silly. There is no 100% safe system on a boat. Electrical fires can and do happen. Even if you go silly and use a solar oven, it's possible it gets bumped and focuses the light on something flamable.

Used with common sense, propane is reasonably safe. If it wasn't it would be outlawed. It does offer a very dense energy storage mediam and still offers the greatest options for cooking. Add in the reliability from a much simpler system and it's hard to beat.