XPM78 - Explorer Yacht

[twistedtree]

If you refer to choice of parallel hybrid for the main engine, and potential for downsizing the main, I don't see how it is really that adventurous.

Idea behind it is choosing a little smaller main, than what would be chosen otherwise.

Lets take a Nordhavn 68 as an example. It is specified with 425hp main engine, and can do 11kts max speed. Cruise speed is 8kts.

When it is going at that 8kts, the main engine is loaded a little lighter than ideal.

Lets choose one size smaller main engine, coupled with an electric engine, same size as the electric wing we are discussing, same coupling clutch as XPM7802 (*). I don't really want to give a figure without calculations, but lets say a 350hp main would do.

Now when we cruise with the main alone at the original cruising speed of 8kts, it is better (more) loaded than bigger main at same powerpoint, right? Electric engine is not engaged at all at this stage, the reliability of the system is just like the original, even higher than before as our main engine will run happily better and longer with better loading, and with better BSFC, all other things being equal, right?

As a bonus, with that electric engine on paralleling coupling/clutch, we can use it for charging with roughly double the efficiency vs conventional alternators. Less heat in the ER, less fuel burned. In fact, we can disconnect the driving belts of original alternators and leave them for ultimate backup.

Now when we want to go higher than top speed of this smaller main engine, at original/desired top speed of 11kts, we boost it with the electric engine. Short term boost comes from the batteries, if we want to go longer than an hour / two we spin up the wing generator as well.

If we want to go slower, we shut down the main. Short term boost comes from the batteries, if we want to go longer than an hour / two we spin up the wing generator as well. This way we could go maybe 4-5kts?

I really like this setup on XPM7802. Only thing I would have done differently is I would have gone with single main engine, but this is a much longer discussion and would never end

Great blog post on main engine loading vs cruising speed vs main engine sizing:

https://mvdirona.com/2015/08/diesel-engine-underload/

I think the parellel hybrid concept is a (big) improvement in the right direction.

A bit like a CPP-prop, but done differently ie. electronically, the end result being the same: wider range of speed on ideal engine loading and resulting better overall fuel economy. In fact, Trasfluid, one manufacturer of these parallel marine transmissions, quotes 10-15% improvement on fuel economy without any other modifications, which to me sounds pretty good.

* something like this:

Parallel Hybrid Solutions | escopower.be

https://www.bateau-electrique.com/docs/moteurs-transfluid.pdf

Interesting stuff, and I agree technically. But I think it's impractical (mostly) in a boats like we are discussing. Let's use numbers that match the real numbers for a N68.



For round numbers, let's say the wing is 150hp. We need to keep that for acceptable get-home propulsion. So, you could reduce the main by 150hp, and make up the 150hp via electric and batteries, backed by the wing engine as a sustained power source.


You would save the cost, and perhaps size but probably not, of a 425hp engine vs 275hp. And there is no reduction in complexity. The 425hp engine operating at 1500 rpm (a typical cruise speed) has a prop load of about 250-275hp, so the 275hp engine selection is about right. Just keep in mind that it will be running full power all the time while underway. So it has to be a continuous duty engine. The 425 is an M2, Deere lingo for I think 16hrs/8hrs duty rating. We need an M1 rated motor.



Now let's compare complexity and cost.



Conventional setup:
- Cost of a 150hp M1 wing engine
- Cost of a 425hp M2 main engine


Hydrid setup:
- Cost of a 150hp M1 wing engine (same)

- Cost of a 275hp M1 engine (less)
- Incremental cost and complexity of a dual input gear box and clutch(es) (more)

- Cost and complexity of a traction battery bank (lots more)

- Cost and complexity of a traction motor and control system (lots more)


All that cost, complexity, and space just so the main can maybe run at a slightly better BSFC? I just don't see the benefit in a boat. It's all worth it in a car where there is inertia energy to recapture via regeneration, but that doesn't exist in a boat.

 

[Chris Leigh-Jones]

Have you a rough estimate on the power required to drive this hull say 4/5/6/7 kts? Ie. how fast do you see yourself going on electric mode alone, and how much range would there be if slowed down a bit?

I'll try to answer. Electric at 30kW per shaft would give us 6/7 knots for 60kW but that's not really where we use it. One diesel at 120kW should give 10.5 knots which is respectable. If we don't care about fuel consumption then 15 knots is about all we have with both diesels running. We have upped the batteries for redundancy so now have 120kWh installed. Even so at full load they are drained in 90 min or so as the power density is not great for electric. So we use it for dynamic positioning and all maneuvering in port, slow stuff taking a minor few kW sporadically at very low prop speeds. (Unlike a diesel there is no minimum speed) We also have a lump of storage for anchorage so charge infrequently. The 30kW motors produce that at 1000 rpm shaft speed before reduction gearbox or 300 rpm prop speed. When used as generators the engine running at 2300 drives them at 3400rpm or close (Esco Power step down drive). So in that mode they produce 96kW for charging and we sized the inverter at 125kW to cover us. Batteries charge in an hour or, as said in another post, maybe a bit slower so as to not stress them overly. I hope that answers your question?

 

[Dav]

All that cost, complexity, and space just so the main can maybe run at a slightly better BSFC? I just don't see the benefit in a boat.

It is not really worth it alone, that I fully agree.

But combined effect, replacing one main + wing + 2 x generators by slightly smaller main and this electric wing generator combo, reduction from four diesel motors to two, while maintaining full redundancy of any one single part failing and of every major function, starts making sense I think. Getting rid of the hydraulic system is a huge saving, by itself, I believe it is a very expensive option, usually. Less stuff in the ER, less stuff to maintain.

I think in the end it boils to these boats not really being essential, thus all choices are not fully rational. Their is still room for personal preferences, and it is a good thing.

 

[dannc]

Great discussion. We have been watching the Artnuatica designs for many years now and we are talking to them at this point. Hopefully we can get to Europe next year to look a yards and meet in person.

Two quick questions:

• Why did you pick JD engines?
• Why did you NOT pick a CPP, Sabb or other brand?

I like JD engines but their lock down of the ECM and tooling is not a good thing. There is at least one lawsuit happening in the US over this issue which maybe will turn this around.

Later,
Dan

 

[Chris Leigh-Jones]

Great discussion. We have been watching the Artnuatica designs for many years now and we are talking to them at this point. Hopefully we can get to Europe next year to look a yards and meet in person.

Two quick questions:

• Why did you pick JD engines?
• Why did you NOT pick a CPP, Sabb or other brand?

I like JD engines but their lock down of the ECM and tooling is not a good thing. There is at least one lawsuit happening in the US over this issue which maybe will turn this around.

Later,
Dan

I'll try to answer both together here.
Artnautica - I know there is a yard in Holland who has built their 55 foot launch, similar to the one built by Dicky Boats in NZ. Denis would know who and if you don't have his mail : dennis@artnautica.com

Our boat is being built at Naval Yachts in Antalya, email again: Barış Dinc <baris.dinc@navalyachts.com>. XPM-002 is 78 feet and I believe this Yard and Dennis are discussing a client build at 85 feet, slightly different hull configuration and possibly with twin CPP.

We looked around a lot at engines. Volvo, Perkins (Cat), Scania, Cummins ..... settled on JD due to their reputation with the FPB range and ability to get W/W coverage. Honestly that's all, I could have been just as happy with a few other makes though some of the good ones like Cummins don't have a small enough unit.

Wayne, who built XPM-001 Mobius, fitted a Gardner engine. Big solid good looking engine with simple mechanicals and high reliability. Mobius have a Nogva mechanical CPP system installed I think. My mate Geoff, was a fisherman out of Holyhead in the UK. All his boats used Gardners. Emissions regs on a new hull mean we cannot do that and bring the boat to the USA or sell in Europe so we went for a more modern design with its attendant complications. There is though, a case for simplicity. No CPP as we can run on electric down to zero speed so don't have the issue of minimum idle speed you have when using Diesel engines. Makes implementing Dynamic Positioning much easier all round. If we did not have hybrid I'd think long about implementing CPP.

Hope this helps.

 

[dannc]

...

Hope this helps.

Yep that helps. Thank you.

Saw two Gardner engines in a boat yard in China that had been remanned and were gong to be put in river/coastal commercial ship. One of the trawlers we visited was going to have a Gardner. Gorgeous engines, and I REALLY want a Gardner, but we can't import them into the US because of the EPA regulations.

The availability of parts for JD is a plus for them, but some of the other engines, as long as they are based on tractor engines, seem to have good availability. The Iveco engines are being used, at least in the US, by Case and New Holland, which have pretty well developed tractor dealer networks. I almost bought a New Holland tractor years ago but bought JD instead. Kubota is everywhere too.

Scania is also an engine I really like but too big for what we need.

Cummins makes a hydraulic driven 10K watt generator that is interesting. Put a hydraulic pump driven by the transmission PTO should properly load the engine when generating power and one could use the hydraulics for other things.

Flip side is that the LRC's have sooooo much room for solar power, it looks like the boat could produce more power than we could use for most of the year and most use cases. Really wondering if we need a generator, or at least, an diesel engine genset.

Later,
Dan

 

[Chris Leigh-Jones]

Yep that helps. Thank you.

Saw two Gardner engines in a boat yard in China that had been remanned and were gong to be put in river/coastal commercial ship. One of the trawlers we visited was going to have a Gardner. Gorgeous engines, and I REALLY want a Gardner, but we can't import them into the US because of the EPA regulations.

The availability of parts for JD is a plus for them, but some of the other engines, as long as they are based on tractor engines, seem to have good availability. The Iveco engines are being used, at least in the US, by Case and New Holland, which have pretty well developed tractor dealer networks. I almost bought a New Holland tractor years ago but bought JD instead. Kubota is everywhere too.

Scania is also an engine I really like but too big for what we need.

Cummins makes a hydraulic driven 10K watt generator that is interesting. Put a hydraulic pump driven by the transmission PTO should properly load the engine when generating power and one could use the hydraulics for other things.

Flip side is that the LRC's have sooooo much room for solar power, it looks like the boat could produce more power than we could use for most of the year and most use cases. Really wondering if we need a generator, or at least, an diesel engine genset.

Later,
Dan

We scraped the Gen sets in favor of a hybrid drive. The nice thing is when run backwards at full Diesel engine speed the Hybrids generate about 3 times their propulsion power. Inverter is matched to that higher input power. So if batteries charge quickly (1C) then you can load up the engine and shut it down quickly. Also got a theoretical 8kW of PV panels on a good day, low latitude. Not sure how that's going to work out in reality but worth a try.

Amusing Story perhaps - In the 1980's I used to work for an engine design consultancy. One of the technicians got hold of a new and expensive Volvo truck engine removed from the test beds and put it in his fishing boat. All was good till he sent them a message for new parts for an engine that was never released to the market. Smelly stuff hit the fan at that point. oops!

 

[twistedtree]

It's probably clear that I don't agree with the value propulsion behind hybrid propulsion, at least not in an expedition boat. A big part of it is that I'm super conservative around critical systems, and want things what have been well proven over a decade or more, and where the suppliers are established and stable, or where alternate vendor parts can be easily substituted. But people like you will pave the way for people like me, so thanks for going first.


One part of this that is quite interesting to me - well, actually it's all interesting, but something I might actually do - is fitting the propulsion engine(s) with high power electric generation, not for propulsion, but for house loads.


I already have a "hybrid" power system for house loads, as do most small boats. House power comes from batteries via inverters, and 90% of the loads are AC loads powered this way. Batteries get charged off the propulsion engine alternators, off shore power, or off an auto-start generator. This is a significant and tangible improvement over a 24/7 generator both in terms of noise and maintenance. A 24/7 generator requires an oil change about once a week, and racks up thousands of hrs a year depending on how much time you spend away from a dock.


With the advent of LFP, generator charge times come down a bunch - 4-5 hrs down to about 2 - all without stressing the batteries and without exotic cooling. That's another big day to day operational improvement. For me, LFP is about as risky and unproven a technology that I can get comfortable with, even though it's been around for 20+ years, studied exhaustively, and is very well understood. But I still have a dual redundant LFP system and a third backup provision to switch the house power over to a small LA bank.


But one of the weak links remains recharging and carrying house load off the propulsion engine alternators. They are horribly inefficient and as a result throw off a lot of heat. Something that's at least more efficient, and ideally higher power would be great. And in conjunction with the quicker recharge rates of LFP, could conceivable replace a generator or two. The challenge there is running the propulsion engine at about a 10% load for the duration of recharge, vs a smaller generator at 80% load.


But on the flip side, if you get rid of the generators then you have a single point of failure for AC in the batteries and in the inverters. Currently I have tripple redundancy for AC power with inverters and two generators.


So many ways to slice the pie....

 

[dannc]

We scraped the Gen sets in favor of a hybrid drive.

...Also got a theoretical 8kW of PV panels on a good day, low latitude. Not sure how that's going to work out in reality but worth a try.

Amusing Story perhaps - In the 1980's I used to work for an engine design consultancy. One of the technicians got hold of a new and expensive Volvo truck engine removed from the test beds and put it in his fishing boat...

Yeah, Volvo is not on the engine list due to parts availability and cost.

The info Artnuatica sent me had information that made me look at hybrid. Beta Marine in the UK has an interesting system that has been in use for enough years to maybe think one is not a pioneer, or too much of a pioneer, if using their hardware.

The wife and I went around and around on hybrid but just don't see how it fits our use cases. But I was, and still am, interested in using the system to generate lots of power fast, while properly loading the diesel. I need to go back and reread again....

Victron has a very nice calculator where one picks one of their solar panels and a location to see how much power one could expect to see for each month of the year. Very interesting numbers. Dec/Jan in higher latitudes is not good for power production.

What I was told in a solar power class years ago, and what some of the online calculators where saying, is that one can expect to get 77% of the power generated by the panels at the wall outlets. At my latitude, we get about five hours of power generating sunlight all year long. A bit more than five in the summer and a bit less in the winter, so just call it five.

So, for 6KW of solar panels, with five hours of power generating sunlight, and at 77% efficiency, we get 6KW * 5 *.77 = 23.1KW! What the heck are we going to do with that much power? There are panels out there with 400-470 watts of power so I think one can get even more wattage if one wants/needs it.

Course, on a boat, one has shading issues to deal with but the LRC's are not sail boats so this should not be too bad. <Cross Fingers>

This amount of solar power generation opens up other design and equipment choices on the boat. Calling it a game changer might be a bit much, but it opens up some interesting design choices.

Later,
Dan

 

[rslifkin]

Victron has a very nice calculator where one picks one of their solar panels and a location to see how much power one could expect to see for each month of the year. Very interesting numbers. Dec/Jan in higher latitudes is not good for power production.

What I was told in a solar power class years ago, and what some of the online calculators where saying, is that one can expect to get 77% of the power generated by the panels at the wall outlets. At my latitude, we get about five hours of power generating sunlight all year long. A bit more than five in the summer and a bit less in the winter, so just call it five.

So, for 6KW of solar panels, with five hours of power generating sunlight, and at 77% efficiency, we get 6KW * 5 *.77 = 23.1KW! What the heck are we going to do with that much power? There are panels out there with 400-470 watts of power so I think one can get even more wattage if one wants/needs it.

Course, on a boat, one has shading issues to deal with but the LRC's are not sail boats so this should not be too bad. <Cross Fingers>

This amount of solar power generation opens up other design and equipment choices on the boat. Calling it a game changer might be a bit much, but it opens up some interesting design choices.

In my mind, the beauty of having that much solar power isn't the crazy amount of power you can produce on a good day in the summer, but how much you'll still get on an overcast day, or in the middle of winter. And now I feel like serious small potatoes with the 2x 410w panels I just mounted on my own boat...

 

[dannc]

...
One part of this that is quite interesting to me - well, actually it's all interesting, but something I might actually do - is fitting the propulsion engine(s) with high power electric generation, not for propulsion, but for house loads.
...

Yeppers! This is what we want to do so we can get rid of the generator. Can we get rid of the generator? :lol:

...
With the advent of LFP, generator charge times come down a bunch - 4-5 hrs down to about 2 - all without stressing the batteries and without exotic cooling. That's another big day to day operational improvement. For me, LFP is about as risky and unproven a technology that I can get comfortable with, even though it's been around for 20+ years, studied exhaustively, and is very well understood. But I still have a dual redundant LFP system and a third backup provision to switch the house power over to a small LA bank.

Yes, LFP's are a game changer, but I don't like the electronics in the battery. Charging at high C rates is possible with LFP but comes at the cost of battery lifetime. Victron, and I think Mastervolt was the same, had higher battery lifetimes at .5C or lower, course the lifetimes at higher C rates is so high that one might not care.

Having said that, for the LRC designs which have so much solar, lead acid technology batteries might not be a bad choice. Weight and volume is still an issue though.

...
But one of the weak links remains recharging and carrying house load off the propulsion engine alternators. They are horribly inefficient and as a result throw off a lot of heat. Something that's at least more efficient, and ideally higher power would be great. And in conjunction with the quicker recharge rates of LFP, could conceivable replace a generator or two. The challenge there is running the propulsion engine at about a 10% load for the duration of recharge, vs a smaller generator at 80% load.

Not sure where I got the number, but what is in my head, is that the engine needs to at 30% or higher to be properly loaded. If it was lower, things get easier.

My holy grail has been to have propulsion engines sized so that they can run alternators that properly load the engine while only generating power. This pretty much means relatively low HP engines. There is a Goldilocks engine HP range that will allows this to happen.

The LRC design, especially if using two engines, seems to put one in the Goldilocks zone regarding proper engine loading while only generating power.

One of the questions I have, for which I don't have the answer, is can an engine block actually handle hanging a large frame alternator on a 70-100 HP engine?

An alternator attached to a PTO would seem to be an answer. Mobius is doing this with one of the two large frame alternators. The problem on some of the LRC models, is that engine room is not very deep so once can start running out of space if using a PTO alternator depending on the size of the alternator, transmission and engine as well as the location of the alternator. This makes the hydraulic power alternator kinda interesting since the alternator can just be moved to a different part of the engine room away from the engine(s).

On the other hand, with as much solar power that is available on the LRC design, does one "need" a huge/large alternator for power production?

One of my ideas is to "just" put in a couple Balmer, or similar alternators, on each engine that can generate a decent amount of power, derate them for long life and for normal usage. If one needs more power because the solar panels are not producing, increase the power production of the alternators when needed, which should not be often.

...
But on the flip side, if you get rid of the generators then you have a single point of failure for AC in the batteries and in the inverters. Currently I have tripple redundancy for AC power with inverters and two generators.

So many ways to slice the pie....

Yes there is. Sooooo, many of these decisions are based on the use cases and preferences.

The "smaller" LRCs are an interesting design because they can use a fair number of the French canals which opens up some interesting routes. The boat can dry out, especially the twin engine models, and has a very shallow draft, both of which opens up more places to explore. The low air draft just adds more places to visit.

The LRC requiring low HP for propulsion, which seems to get us to a Goldilocks zone of properly loaded engines for power production, as well as the solar power production on the LRC, creates some interesting ways to slice the design/feature pie.

With two propulsion engines that can produce power, as well as solar panels, one has a decent amount of power producing redundancy. One could add wind generators but that seems over the top at this point and one has to be careful of solar panel shading.

Later,
Dan

 

[Chris Leigh-Jones]

Yeah, Volvo is not on the engine list due to parts availability and cost.

The info Artnuatica sent me had information that made me look at hybrid. Beta Marine in the UK has an interesting system that has been in use for enough years to maybe think one is not a pioneer, or too much of a pioneer, if using their hardware.

The wife and I went around and around on hybrid but just don't see how it fits our use cases. But I was, and still am, interested in using the system to generate lots of power fast, while properly loading the diesel. I need to go back and reread again....

Victron has a very nice calculator where one picks one of their solar panels and a location to see how much power one could expect to see for each month of the year. Very interesting numbers. Dec/Jan in higher latitudes is not good for power production.

What I was told in a solar power class years ago, and what some of the online calculators where saying, is that one can expect to get 77% of the power generated by the panels at the wall outlets. At my latitude, we get about five hours of power generating sunlight all year long. A bit more than five in the summer and a bit less in the winter, so just call it five.

So, for 6KW of solar panels, with five hours of power generating sunlight, and at 77% efficiency, we get 6KW * 5 *.77 = 23.1KW! What the heck are we going to do with that much power? There are panels out there with 400-470 watts of power so I think one can get even more wattage if one wants/needs it.

Course, on a boat, one has shading issues to deal with but the LRC's are not sail boats so this should not be too bad. <Cross Fingers>

This amount of solar power generation opens up other design and equipment choices on the boat. Calling it a game changer might be a bit much, but it opens up some interesting design choices.

Later,
Dan

Dan - have a look at Hybrid Marine - nice simple small system that will work as a hybrid and fits Beta and JD, probably others also. Also work as a really big alternator if you wish. This is the guy's email: Graeme Hawksley <graeme@hybridmarine.co.uk> I like simple one man band companies with a passion for what they do. I was there at one time. Good luck. Chris

 

[dannc]

In my mind, the beauty of having that much solar power isn't the crazy amount of power you can produce on a good day in the summer, but how much you'll still get on an overcast day, or in the middle of winter. And now I feel like serious small potatoes with the 2x 410w panels I just mounted on my own boat...

Bing! Bing! Bing!

Exactly.

From looking at sailboats, where putting in 1,000 watts of non shaded panels is about all one can expect, but at the cost of sailing performance, the idea of having 5K, or more, of solar panels was an eye opener. It took me awhile to realize your point regarding winter power production. The wife and I discussed what this surplus power meant and it took awhile to get away from the sailboat mindset to realize the design point was winter time solar power production vs not having enough power to get through the normal day.

I have been joking that we could supply power and water to quite a few boats in the anchorage. Visions of extension cord and water hoses spanning out from the LRC.... :lol:

The design point then becomes having enough power on the horrible power production days in Dec/Jan, if in higher latitudes. That means one has so much available power for the rest of the year, that one can consider using less energy efficient fridges/freezers that are easy to use and store more food vs energy efficient fridges/freezers that are hard to use and don't store much food.

It also opens up using some HVAC from the surplus power....

Later,
Dan

 

[Chris Leigh-Jones]

It's probably clear that I don't agree with the value propulsion behind hybrid propulsion, at least not in an expedition boat. A big part of it is that I'm super conservative around critical systems, and want things what have been well proven over a decade or more, and where the suppliers are established and stable, or where alternate vendor parts can be easily substituted. But people like you will pave the way for people like me, so thanks for going first.


One part of this that is quite interesting to me - well, actually it's all interesting, but something I might actually do - is fitting the propulsion engine(s) with high power electric generation, not for propulsion, but for house loads.


I already have a "hybrid" power system for house loads, as do most small boats. House power comes from batteries via inverters, and 90% of the loads are AC loads powered this way. Batteries get charged off the propulsion engine alternators, off shore power, or off an auto-start generator. This is a significant and tangible improvement over a 24/7 generator both in terms of noise and maintenance. A 24/7 generator requires an oil change about once a week, and racks up thousands of hrs a year depending on how much time you spend away from a dock.


With the advent of LFP, generator charge times come down a bunch - 4-5 hrs down to about 2 - all without stressing the batteries and without exotic cooling. That's another big day to day operational improvement. For me, LFP is about as risky and unproven a technology that I can get comfortable with, even though it's been around for 20+ years, studied exhaustively, and is very well understood. But I still have a dual redundant LFP system and a third backup provision to switch the house power over to a small LA bank.


But one of the weak links remains recharging and carrying house load off the propulsion engine alternators. They are horribly inefficient and as a result throw off a lot of heat. Something that's at least more efficient, and ideally higher power would be great. And in conjunction with the quicker recharge rates of LFP, could conceivable replace a generator or two. The challenge there is running the propulsion engine at about a 10% load for the duration of recharge, vs a smaller generator at 80% load.


But on the flip side, if you get rid of the generators then you have a single point of failure for AC in the batteries and in the inverters. Currently I have tripple redundancy for AC power with inverters and two generators.


So many ways to slice the pie....

I could be convinces that hybrids are not the answer also but wanted to explore the concept a bit. One big bug bear I had was loading up the diesels to recharge batteries. The answer lay in the step up drive for the hybrid motor (Esco Power). Here is how that worked out:
At 30kW e-motor drive max we are turning 1000 shaft RPM to have the prop absorb this power input at about 300RPM. BUT when prop law does not apply, ie in neutral on the gearbox, we can run the e-motor as a generator at 2300RPM shaft (max 2600) RPM being max engine speed. This generates 96kW theoretically meaning our diesel is now loaded up sufficiently (120kW full load capacity) and the batteries charge in quick time, perhaps a little quickly for long life. Engine loading is now solved and it does not hang around at near idle. A slippery hull and low power main engine requirement helps in this respect.

p.s. did anyone see the post on FLIR? Looks interesting but it may be the hype, I've no direct experience other than police You Tube video's. Perhaps someone could chime in?

 

[Fletcher500]

Hi Chris,

Sounds like a great project, and you will have an amazing vessel when done.

I can't offer anything relevant as my motor and battery education ended 30 years ago, but I have been following along and learning. Good stuff.

Question regarding DPS; what do you foresee using this capability for?

 

[Fletcher500]

FLIR - There are people on here that have sophisticated systems, so I will defer to them. My .02: I don't do extensive overseas travel like you have planned, but we do some long coastal runs, and often at night. I had an occasion about 5 years ago where a small un light boat became a problem, and I figured I would have seen them with a Flir. I therefore bought a Flir handheld, I believe the 640 model. It works pretty good, just like binoculars at night. Glad I have it. I have considered mounting one of the high end units on the arch, but I am not sure the bang for the buck is there based on people I have talked to. Still may happen at some point.

 

[Chris Leigh-Jones]

Hi Chris,

Sounds like a great project, and you will have an amazing vessel when done.

I can't offer anything relevant as my motor and battery education ended 30 years ago, but I have been following along and learning. Good stuff.

Question regarding DPS; what do you foresee using this capability for?

Thank you Mr Fletcher for sharing your knowledge. I'm thinking of buying one of those hand held FLIR to play with a while before splashing a more substantial amount if at all. I tend to measure costs in pints of beer not $$. Then make the value judgement, where is the most joy to be found, A or B?!

 

[twistedtree]

I could be convinces that hybrids are not the answer also but wanted to explore the concept a bit. One big bug bear I had was loading up the diesels to recharge batteries. The answer lay in the step up drive for the hybrid motor (Esco Power). Here is how that worked out:
At 30kW e-motor drive max we are turning 1000 shaft RPM to have the prop absorb this power input at about 300RPM. BUT when prop law does not apply, ie in neutral on the gearbox, we can run the e-motor as a generator at 2300RPM shaft (max 2600) RPM being max engine speed. This generates 96kW theoretically meaning our diesel is now loaded up sufficiently (120kW full load capacity) and the batteries charge in quick time, perhaps a little quickly for long life. Engine loading is now solved and it does not hang around at near idle. A slippery hull and low power main engine requirement helps in this respect.

p.s. did anyone see the post on FLIR? Looks interesting but it may be the hype, I've no direct experience other than police You Tube video's. Perhaps someone could chime in?

Makes sense, and works with your large traction batteries, and cooling to accept 1C charging. I think it's harder for a house bank which would be significantly smaller, and likely un-cooled and only chargeable at .5C or lower. But as DanNC pointed out, twins helps a lot because you have half the HP to underload vs a single engine.


I'll reply to the other FLIR thread. I've used one for a while.

 

[twistedtree]

OK, I don't see another FLIR thread, so here goes....


I really like them, but they aren't cheap and have narrow uses, so are down the list of priorities for electronics.


You asked about ice, and I think that's one area where they really shine (pun intended). We were poking around the Columbia Glacier a few years ago and the water was littered with growlers that were smooth and rounded and nearly impossible to see until you were right on top of them. This was in broad daylight. But boy did they light up on the FLIR.


I have also had it save my bacon once getting into a tight harbor entrance with a very inconvenient dog leg, and absolute pitch darkness with nothing but blinding backlighting on shore. Once again, FLIR to the rescue, making everything visible.


What they are not as good at are showing floating junk in the water because there generally is less of a temp contrast. You can see crab/lobster floats, and wood and stuff, but it doesn't light up like ice does.


The only advice I have is to be sure to get the higher resolution version so you really get the full benefit. Many of the models now include stabilization which I'm really looking forward to. My current installation in an M364 which is pan-tilt, and stabilized. But I have yet to turn it on. In fact, I don't think I have it completely hooked up yet. So much to still do....

 

[dannc]

Dan - have a look at Hybrid Marine - nice simple small system that will work as a hybrid and fits Beta and JD, probably others also. Also work as a really big alternator if you wish. This is the guy's email: Graeme Hawksley <graeme@hybridmarine.co.uk> I like simple one man band companies with a passion for what they do. I was there at one time. Good luck. Chris

Yes, I looked at Hybrid Marine and they have some very, very, interesting products.

One of my concerns was the big, honking generator hooked up to the prop shaft. That was much less of a concern after I saw a video they have on YouTube showing that one can manually disconnect the generator from the prop shaft. That removed a good bit of my concern. The system looked a wee bit robust.

Depending on how one calculates HP requirements, and the engine HP, their solution was going to load the engine at 43-53%!

They have been had this in the field for long enough so that one should not be a pioneer collecting arrows with their product.

At this point, for what we want to do, I think decent sized alternators will work because the LRC has so much solar power capability. Having said that, the other design decision is should one use electric power or hydraulics, to run winches, pumps, windlass, etc? That gets me back to the idea of having a hydraulic pump on the transmission PTO. If one goes down that path, then the Cummins hydraulic generator is possible, but I am not sure that is even needed...

There is a conversation on Cruising Forum from a few years ago discussing the build of an AL sail boat in the NL. There are some very good ideas in that discussion. The owners wanted, and got, a fairly simple boat, but there are interesting discussions regarding ventilation, heating, deck covering, deck color to minimize heat gain, electrical, etc. It is a treasure trove of information irregardless of how the boat is moved through the water.

https://www.cruisersforum.com/forums/f47/bestevaer-49st-147499.html

Oh, yeah, when do you get more images of the boat being built? More Please.

Thank you for the link,
Dan

 

[Dav]

It's probably clear that I don't agree with the value propulsion behind hybrid propulsion, at least not in an expedition boat. A big part of it is that I'm super conservative around critical systems, and want things what have been well proven over a decade or more, and where the suppliers are established and stable, or where alternate vendor parts can be easily substituted. But people like you will pave the way for people like me, so thanks for going first.

One part of this that is quite interesting to me - well, actually it's all interesting, but something I might actually do - is fitting the propulsion engine(s) with high power electric generation, not for propulsion, but for house loads.

I think you are slowly starting to accept it, your second paragraph is a good start... I think main point is to stop comparing it to a hybrid system in a car. It is not meant to capture inertial energy, a totally different use case.

You could "just" have a big BLDC-type motor/generator hooked into your main engine, and only use it for charging, nothing more. Quick benefit is around double the efficiency (98% vs 50%) vs conventional alternators and thus much less heat in the ER and some fuel saved. This motor obviously does not need to have that disconnecting clutch setup mentioned, it could be mounted into a PTO-slot or even belt driven. Old alternator belts taken away, but stored as a backup. Fast charging also on high idle, same time acting as a backup for the genset. Sounds good?

Then next step for a new boat would be this same PTO mounted BLDC-type motor/generator, but a size smaller main engine. Still no disconnecting clutch, slightly better loading and economy at cruise speed, slightly lower top speed. But an option to boost top speed back to original by electric assist.

These options above give you also an another, parallel way to start the engine, in case the starter or start battery fails.

We could call the above a "light hybrid", and it already brings you the benefits of charging and better economy + boosted top speed, ie. wider optimal speed band availability. You could very well start with this.

You only need the disconnecting clutch if you want to drive the boat with diesel engine shut down / unavailable. This is either intentional, you want to drive real slow, either cruising or docking or changing main engine oil while underway or dynamic positioning - which I think would be way cool to be able to do safely and reliably for quick "anchoring" - or as a get home option. One might even be happy with this as a main get home option, only downsize it is relies on main prop and shaft being relatively undamaged.

And only complexity this adds into the system is this one clutch in the driveline. I think that is quite mature technology, there is usually a manual "backup" mode available where you shut down everything else and drive the main engine just like before. I don't see many probable failure modes that would worry me in this system.

 

[Dav]

Why did you NOT pick a CPP, Sabb or other brand?

I think CPP is a wonderful piece of technology, but this parallel hybrid system solves the same issue, being able to drive the boat in a wider range of optimal speeds, even better. You can literally drive at 0.1kts, if you want to, with electric engines.

CPP is also expensive in a boat of this size. I talked to Nordhavn, they said the CPP system on N56MS is almost 100k usd - I do not know how accurate this estimate is, but it is still expensive if it really costs half of this. That is a lot of money, I would assume pricewise a hybrid system could be built for a substantially less money, and you can add more battery afterwards.

CPP is also fragile, in a way that if you hit that prop into something hard, it will be hard to fix, and spares are not available in the remote locations. For a fixed prop you can carry a spare.

I have visited many FPBs, they carry spare props, many of them. You might not be able to change the prop yourself, but you can always hire a diver to do this, in any port in the world.

 

[Dav]

I'm thinking of buying one of those hand held FLIR to play with a while before splashing a more substantial amount if at all. I tend to measure costs in pints of beer not $$. Then make the value judgement, where is the most joy to be found, A or B?!

My only advice on this is don't buy one before the launch. The prices are coming down like crazy.

I have a few CCTV ones I intend to monitor wildlife with, I plan to install them in the coming weeks to my house to try them out.

It comes from a reputable brand, one of the top players in the field, has multiple field of view options, optional visible light camera as well, has an IP67 outdoor enclosure, works in winter all the way to -40C.

It costs _way_ sub 1000 usd. Amazing, I say. I used to buy similar units at work for 50k - 100k usd, and it was not that long ago.

 

[Dav]

We scraped the Gen sets in favor of a hybrid drive.

If you ever end up doing inland waterways, adding a small gen is always easy, just save a spot in the ER.

This way you could hit the speed limit all day long and not clog the main engines with low rpms and loading.

In fact, I would maybe consider adding one already, but main thing is to save a spot in the ER for future and maybe even add the plumbing while it is being built, much easier at that stage.

 

[Dav]

But on the flip side, if you get rid of the generators then you have a single point of failure for AC in the batteries and in the inverters. Currently I have tripple redundancy for AC power with inverters and two generators.

Splitting the battery bank into two (or three) and having multiple parallel inverters, as many as you want?

Wastes nothing as they can all be actively used.

Could even carry a spare LFP cell or few and/or a spare inverter.

 

[Dav]

This amount of solar power generation opens up other design and equipment choices on the boat. Calling it a game changer might be a bit much, but it opens up some interesting design choices.

It does.

With a wide enough a boat, say this 78ft long XPM but say with 36ft wide hull, you could _easily_ have enough solar to cover your propulsion needs, at least for slower speed cruising and/or shorter trips provided you have enough battery capacity (*). But a 36ft wide boat will be rather heavy and a lot of drag.

If there only was a way to split this hull into say two parts.

* 58kW or thereabouts.

 

[Dav]

When used as generators the engine running at 2300 drives them at 3400rpm or close (Esco Power step down drive).

- any reason not going with the higher 1.7x ratio vs 1.4x chosen?

- can you give a rough estimate/ballpark figure on the cost of one such Esco Power clutch? What about the e-motors and inverters, just to give rough idea?

 

[Dav]

Yes, LFP's are a game changer, but I don't like the electronics in the battery.

Me neither. I would definitely keep the batteries themselves 100% passive and have an external BMS.

Charging at high C rates is possible with LFP but comes at the cost of battery lifetime.

The answer is having enough battery capacity. LFP is now like 100-200 usd minimum for kWh, so the cost is fairly reasonable. I would always go for double the max charging capacity in kW for battery capacity in kWh, triple is even better.

These boats like the ballast, this way we can make it do something useful as a bonus vs just adding lead...

 

[twistedtree]

I think CPP is a wonderful piece of technology, but this parallel hybrid system solves the same issue, being able to drive the boat in a wider range of optimal speeds, even better. You can literally drive at 0.1kts, if you want to, with electric engines.

CPP is also expensive in a boat of this size. I talked to Nordhavn, they said the CPP system on N56MS is almost 100k usd - I do not know how accurate this estimate is, but it is still expensive if it really costs half of this. That is a lot of money, I would assume pricewise a hybrid system could be built for a substantially less money, and you can add more battery afterwards.

CPP is also fragile, in a way that if you hit that prop into something hard, it will be hard to fix, and spares are not available in the remote locations. For a fixed prop you can carry a spare.

I have visited many FPBs, they carry spare props, many of them. You might not be able to change the prop yourself, but you can always hire a diver to do this, in any port in the world.

Part of the issue, CPPs included, in that this ends up being an exercise in performance tuning in the noise margin. Fuel economy, which is the driving factor for performance improvements like this, is so overwhelmingly dominated by boat speed that it's hard to get excited about fine tuning beyond a conventional drive. A fractional change in speed, like 1/4 kt, will obliterate any savings from these more complex systems. After all, the only thing they really do performance-wise is operate the engine at a somewhat better BSFC point. And any generator-battery-motor derived power has losses that add up to 10-15% best case, which is probably about the same as the BSFC improvement.


So to me the question is whether there is some significant operational benefit to these systems. Dynamic positioning? OK, that would be neat, but I don't find holding station to be frequent enough or troublesome enough to want to pay or complicate my boat for that. If I were a drilling rig that needed to stay spot on for 6 months, sure. But I'm not.


I just think this is solving a problem that isn't near the top of the list of real problems on a boat like this. At least that's my take after running one for a reasonable amount of time. Now if you want to do it because it's cool and you want to do it, go for it. Nobody needs any more excuse than that, this coming from a guy who has done his fair share of "because I want to" projects. That seems to be the case with Chris, and I'm sure we will all learn a lot from it.

 

[twistedtree]

I think you are slowly starting to accept it, your second paragraph is a good start... I think main point is to stop comparing it to a hybrid system in a car. It is not meant to capture inertial energy, a totally different use case.

You could "just" have a big BLDC-type motor/generator hooked into your main engine, and only use it for charging, nothing more. Quick benefit is around double the efficiency (98% vs 50%) vs conventional alternators and thus much less heat in the ER and some fuel saved. This motor obviously does not need to have that disconnecting clutch setup mentioned, it could be mounted into a PTO-slot or even belt driven. Old alternator belts taken away, but stored as a backup. Fast charging also on high idle, same time acting as a backup for the genset. Sounds good?

Then next step for a new boat would be this same PTO mounted BLDC-type motor/generator, but a size smaller main engine. Still no disconnecting clutch, slightly better loading and economy at cruise speed, slightly lower top speed. But an option to boost top speed back to original by electric assist.

These options above give you also an another, parallel way to start the engine, in case the starter or start battery fails.

We could call the above a "light hybrid", and it already brings you the benefits of charging and better economy + boosted top speed, ie. wider optimal speed band availability. You could very well start with this.

You only need the disconnecting clutch if you want to drive the boat with diesel engine shut down / unavailable. This is either intentional, you want to drive real slow, either cruising or docking or changing main engine oil while underway or dynamic positioning - which I think would be way cool to be able to do safely and reliably for quick "anchoring" - or as a get home option. One might even be happy with this as a main get home option, only downsize it is relies on main prop and shaft being relatively undamaged.

And only complexity this adds into the system is this one clutch in the driveline. I think that is quite mature technology, there is usually a manual "backup" mode available where you shut down everything else and drive the main engine just like before. I don't see many probable failure modes that would worry me in this system.

I'm not sure what I'm "slowly accepting", but I've been running "big" alternators for quite a while now. I just don't like the heat they throw off, so if that can be improved, and still be repairable on a remote island, I'm interested.