XPM78 - Explorer Yacht

[twistedtree]

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.

Cool, what's the camera?

 

[twistedtree]

Splitting the battery bank into two (or three)

Done

and having multiple parallel inverters, as many as you want?

Done, but keep in mind that all the usual-suspect inverters shut down if a stacked member goes tits up, and re-programming is required to get them back on line. For some people that's no big deal and can be done in minutes, but for most it would mean no AC power for the rest of the trip.

 

[twistedtree]

The answer is having enough battery capacity. LFP is now like 100-200 usd minimum for kWh, so the cost is fairly reasonable.

Where are you finding that price? I'll take a few of those


I suspect a bunch of the disconnect here is the difference between engineering at a desk, and then having to crawl through a boat to install, diagnose, and fix the resulting products, or having to live with operating a boat using them.


Deere is a good example. It is blatantly obvious that the people who engineer the marinization of their engines have never used them, serviced them, or in any way turned a wrench on them for even the simplest repair. My past 6090 require two experienced guys and two days to replace the coolant pump. And the 4045 in question here has a nicely dressed and bracketed wiring harness, including a disconnect plug, that blocks removal of the raw water impeller and ensures the connector and harness will get doused in salt water at every impeller change. Brilliant. Just brilliant.

 

[dannc]

...
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.
...

Well, Nordhavn's are expensive boats. The price for the engine AND CPP transmission we have been sent is under 50K for an LRC.

The CPP's I have read about can have the prop blades replaced on the hub. Just carry spares like one would do with a fixed prop. The CPP blades would be easier to replace since one is just replacing a blade compared to the whole prop.

Later,
Dan

 

[Dav]

Well, Nordhavn's are expensive boats. The price for the engine AND CPP transmission we have been sent is under 50K for an LRC.

Which brand and which power rating is this?

N56 has Hundested brand CPP and most likely oversized a bit to be on a safe side. Not the most affordable brand of CPPs. It is not just being on Nordhavn.

The CPP's I have read about can have the prop blades replaced on the hub. Just carry spares like one would do with a fixed prop. The CPP blades would be easier to replace since one is just replacing a blade compared to the whole prop.

In theory yes.

In practice it is not quite this easy. If you ding the prop a bit, then just maybe yes, but if the internals are damaged/stuck, it requires much more involved repairs/replacement. Most likely hauling out and pulling the shaft in any case.

 

[Dav]

Where are you finding that price? I'll take a few of those

That is the minimum end of the price range, as stated.

280Ah LFP cells are now available for sub 100 usd. Quality cells a bit more, but I think you should find pretty good ones in the 200 - 300 usd / kWh range, if buying direct from the manufacturer - China that is.

With the most affordable cells you most likely also need to buy a few extra cells and be able to measure and select the good ones and eliminate the bad ones. A good battery cell tester is needed for this.

Or you can buy a brand name battery and pay 5000 usd per kWh.

Maybe the optimal is somewhere in the middle.

 

[Dav]

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.

These BLDC type motor/generator will do the trick. They are 99% passive units, in a sense that only thing needing maintenance is the bearing. Properly fused they won't ever fail, as fusing protects the windings from melting in case of short circuit etc. Heck, you could carry a roll of spare wire for the windings, but that would be excessive I think.

What might need maintenance/spares in the remote island is the controller. Carry few spares, that should do it.

Though I think you could device a crude charge controller from spare parts yourself, if you did not need the motor part. Rectifier bridge, large cap and pwm chopper controlling the charge current. Maybe an old/modified PV charge controller could do?

This would not be as efficient as proper BLDC-controller, but should beat the old car type alternators by a wide margin.

 

[Dav]

Cool, what's the camera?

It is a generic HIK Vision brand unit, there are many models available - I have to check my exact model. "Thermal Network Bullet Camera" gives results.

Also "name brand" Axis P1280E is sub 1000 usd:

https://www.axis.com/files/datasheet/ds_p1280e_t10080225_en_2103.pdf

That might be just an ideal unit for ER monitoring!

 

[Dav]

Cool, what's the camera?

Slight correction, the prices are now sub 500 usd

 

[dannc]

Which brand and which power rating is this?

N56 has Hundested brand CPP and most likely oversized a bit to be on a safe side. Not the most affordable brand of CPPs. It is not just being on Nordhavn.
...

In practice it is not quite this easy. If you ding the prop a bit, then just maybe yes, but if the internals are damaged/stuck, it requires much more involved repairs/replacement. Most likely hauling out and pulling the shaft in any case.

N67 150 HP and CPP Helseth 3H60-830 HS.

If one damages the prop shaft, CPP or fixed pitch, one is pulling the shaft. Don't really see much difference there and given the LRC design, not likely to happen.

Later,
Dan

 

[Dav]

N67 150 HP and CPP Helseth 3H60-830 HS.

Ok thanks!

If one damages the prop shaft, CPP or fixed pitch, one is pulling the shaft. Don't really see much difference there and given the LRC design, not likely to happen.

If you hit a blade to anything at all solid, there is a fair risk for the internal pitch control mechanism getting damaged also. In fact, I would be surprised for damage to be limited in such a way, that it would require just replacement of one blade but nothing more.

For a fixed prop, such a blade hit is much less likely to damage the shaft, even if something solid is hit. Not impossible, but it is quite often that the prop is damaged but the shaft remains just fine.

 

[dannc]

Chris,

Is the lock down in Turkey halting work on the boat or is the boat yard considered essential?

Turkey is getting hit hard with this latest pandemic wave.

Later,
Dan

 

[Chris Leigh-Jones]

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.

Thanks for posting. Funny that I just had the same conversation with Praxis. We have split the whole DC bus bar and drivelines. Now got 2 60kWh battery banks that can run independently port and stud (but crosswise). Need to engineer a cooling system for them also and I'll keep that duplicated in case it becomes the point of failure which would be flat embarrassing really.

 

[Chris Leigh-Jones]

Chris,

Is the lock down in Turkey halting work on the boat or is the boat yard considered essential?

Turkey is getting hit hard with this latest pandemic wave.

Later,
Dan

Turks are getting it in the neck but not as badly off as the Indians. The Turkish Government considers manufacturing as an essential industry so its all open. It was the same last Christmas when we visited, had most of Istanbul to ourselves which never happens in the real world. Be careful if visiting though, there may be restrictions returning, it changes by the month. We live in strange times my friend. Have not seen may family in the UK for 18 months now.

 

[Dav]

Need to engineer a cooling system for them also and I'll keep that duplicated in case it becomes the point of failure which would be flat embarrassing really.

Are these batteries you chose (did you mention the brand) liquid or air cooled?

If the battery cooling did happen to fail, I think it should be not _that_ critical if you monitor the battery temperature and limit the charging current accordingly. I think it - the temp - should be monitored anyways, it might give an early warning of some issue if it raises over norminal without a clear reason. Pt100 probes ftw and many of them!

Or if it is liquid cooling, passive convection can do wonders as the thermal load is still pretty reasonable compared to motors or power electronics.

BTW can you share the ballpark price for the Esco paralleling / disconnecting clutch. Like is it 5k, 10k, 50k, 100k a piece? Just to give a rough idea - and I'll be only needing one

 

[Chris Leigh-Jones]

Are these batteries you chose (did you mention the brand) liquid or air cooled?

If the battery cooling did happen to fail, I think it should be not _that_ critical if you monitor the battery temperature and limit the charging current accordingly. I think it - the temp - should be monitored anyways, it might give an early warning of some issue if it raises over norminal without a clear reason. Pt100 probes ftw and many of them!

Or if it is liquid cooling, passive convection can do wonders as the thermal load is still pretty reasonable compared to motors or power electronics.

BTW can you share the ballpark price for the Esco paralleling / disconnecting clutch. Like is it 5k, 10k, 50k, 100k a piece? Just to give a rough idea - and I'll be only needing one

Dan - batteries are from Praxis Automation but they are the integrator not the initial cell manufacturer. Cooling is 50/50 water/Glycol with inlet temp of 35 deg.C. It can go higher but then they de rate the batteries in terms of their charge or discharge rates. Temp is monitored I believe as is balance between cells, charge rate ....... I'll pm you the price indication and a contact at Esco.

Chris

 

[Iggy]

Sounds like a dream project for an engineer or any boat geek. I like your management style: cruise the BVI on a cat while the work is underway.

I look forward to following the adventure.

Yep!!! Wow, what a boat.

 

[Chris Leigh-Jones]

Anyone have a clue how to correct a spelling mistake in a thread title? I was drinking a bit when I started the thread and now its annoying the heck out of me. "Punishment" I suppose but what for? XPM78-Explorer"e" yacht.

 

[koliver]

Anyone have a clue how to correct a spelling mistake in a thread title? I was drinking a bit when I started the thread and now its annoying the heck out of me. "Punishment" I suppose but what for? XPM78-Explorer"e" yacht.

Done.

 

[Chris Leigh-Jones]

Done.

Thanks.

 

[dannc]

Turks are getting it in the neck but not as badly off as the Indians. The Turkish Government considers manufacturing as an essential industry so its all open...

That is good that manufacturing is still going. The workers and company need the money and you need a boat. More seriously, I know times are hard in Turkey so having work is really important.

Yes, it is strange times. We had hoped to visit the NL this time last year, but of course, we had to cancel. Hopefully next year we can get to the NL and Turkey. <CrossFingers>

Turkey seems like a great place to visit, though I am afraid the food might cause my waist size to increase...

Later,
Dan

 

[Chris Leigh-Jones]

Had an update for the yard today. Main deck is welded and set on the jigs ready to stand the bulkheads. They sanded the surface where welds will fall so we have clean metal to weld to.

The Yard sent me an update, bulkheads are assembled and ready for setting on to the upturned decks. I think they now have to wait for more materials in from the water jet cutters. They also updated the GA as we agreed aft cabin layout. ER entrance moved to midships between the engines to save space, got a lot to squeeze in to her narrow beam. No lockdown at the yard. Chris

 

[dannc]

The Yard sent me an update, bulkheads are assembled and ready for setting on to the upturned decks. I think they now have to wait for more materials in from the water jet cutters. They also updated the GA as we agreed aft cabin layout. ER entrance moved to midships between the engines to save space, got a lot to squeeze in to her narrow beam. No lockdown at the yard. Chris

In a surprisingly short period of time, that flat stuff is going to magically transform into a boat.

Later,
Dan

 

[aktxyz]

Wow, what a great thread. There went my morning and early afternoon catching up.

Actually seeing welded aluminum is very inspiring ... s*** just got real.

 

[Chris Leigh-Jones]

In a surprisingly short period of time, that flat stuff is going to magically transform into a boat.

Later,
Dan

Just as you said!

 

[Chris Leigh-Jones]

They sent me an update. There is a period building a home that is, to be honest, quite depressing. A boat load (exc the pun) of money goes in the ground up to soil level and it still looks the same aka a mud pit. Then magically, it pops up and starts to go vertical. I build homes and see my client's faces change just as magically.

Our yacht just entered that phase. Here are two photo's. the first is the collision bulkhead aft of the forepeak, the second is the bulkhead fwd of the rear cabin. I guess X!@?? just got real! Ha!

 

[socalrider]

They sent me an update. There is a period building a home that is, to be honest, quite depressing. A boat load (exc the pun) of money goes in the ground up to soil level and it still looks the same aka a mud pit. Then magically, it pops up and starts to go vertical. I build homes and see my client's faces change just as magically.

Our yacht just entered that phase. Here are two photo's. the first is the collision bulkhead aft of the forepeak, the second is the bulkhead fwd of the rear cabin. I guess X!@?? just got real! Ha!

Congrats! Must be so satisfying to see progress!

I know the house thing goes in phases as you said - I imagine you'll eventually see an analogous perceived slowdown once the vessel is skinned and the endless finish work begins! But by then you'll have a boat, rather than a set of drawings, an empty bank account, and a pile of metal plate. Thanks again for this thread.

 

[aktxyz]

Great stuff ! I also love the fork lift crane setup, very clever.

Keep the pics flowing, as Helen of Troy said, you can never have too many pics.

Hopefully I will be starting a similar thread soon to track progress, we signed a contract with the same yard and designer recently, drafting off Chris and Wayne

 

[Chris Leigh-Jones]

Great stuff ! I also love the fork lift crane setup, very clever.

Keep the pics flowing, as Helen of Troy said, you can never have too many pics.

Hopefully I will be starting a similar thread soon to track progress, we signed a contract with the same yard and designer recently, drafting off Chris and Wayne

Hey Andrew - you sleuthing me? Wasn't it Robert the Bruce who said "You can never have too many Picts!" or am I confusing my history?

 

[RWestermann]

Artnautica Europe -- yard in Holland (Aluboot)

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.

Hi Chris,


Let me elaborate a bit here. As you know I represent Artnautica Yacht Design (Dennis Harjamaa NZ) in Europe.


The Dutch yard you are referring to is Aluboot (Hindeloopen). Aluboot has built the single-engine 90HP Beta Marine LRC58-3 Britt (2017) which I own and just a week ago Aluboot launched the twin-engine (2 x 75HP Beta Marine) LRC58-5 Aldania. Both have fixed propellor systems.


Have a look at http://artnautica.eu and I also post on Instagram (http://instagram.com/artnautica.eu).

Rob Westermann