Used, Laid Up Trawler about 50 ft

[Hybrid1]

I am looking to purchase a laid up, two engine, Trawler, not a Salvage Vessel, about 50 ft. I am working on converting an older vessel to a Plug-in Hybrid. I will need to remove the engines and genset and replace them with the Hybrid power train, high capacity Lithium batteries, control system, inverters. i am in Southwest Florida, but will travel for the right vessel.

 

[Comodave]

Welcome aboard.

 

[twistedtree]

I'd love to hear more about your hybrid plans, how you envision using the boat, and what sort of performance you expect. And what are you goals? Quiet running, and if so, what % of operating time? Better fuel efficiency for diesel/gas operation? Ability to supplement diesel/gas with renewables, and if so, what portion?

 

[Mambo42]

Welcome aboard and am very interested in hearing what you have in mind.

 

[Delta Riverat]

Me too!

All electric with fuel generator to feed batts/motors or clutched engine to props?

What size motors and controllers? What size batteries? How much solar?

Cool project!

 

[boomerang]

I remember a thread started by a poster with the same aspirations several years ago. I think he had a Gulf Star 36. His postings came to a halt so I don't know if he found the task insurmountable ,found the cost prohibitive or what but I do know lots of people have the same dream of converting an old boat to electric or hybrid but have never known of anyone's plans to come to fruition.

 

[Hybrid1]

Thanks for your interest. Right now, I am a bit hesitant to discuss much of the project, except to say that I have been working on this project for about two years. The biggest obstacle so far has been selecting the right technology and technology supplier. Finally, i have a technology supplier. Now my challenge is the vessel. Once I get the vessel, I will be happy to share what i have learned. In general, I plan to cruise on the batteries leaving and entering marinas and slow zones using about 2 hours of battery capacity and hull speed. In SW Florida, we have lots of slow zones.

 

[PierreR]

Thanks for your interest. Right now, I am a bit hesitant to discuss much of the project, except to say that I have been working on this project for about two years. The biggest obstacle so far has been selecting the right technology and technology supplier. Finally, i have a technology supplier. Now my challenge is the vessel. Once I get the vessel, I will be happy to share what i have learned. In general, I plan to cruise on the batteries leaving and entering marinas and slow zones using about 2 hours of battery capacity and hull speed. In SW Florida, we have lots of slow zones.

There are very few good vessels for a hybrid conversion. The difference between the two propulsion system in terms of energy density and power is an order of magnitude in the marine world. When good mileage is 3mpg, not 40mpg and even at 40mpg, the range of electric is marginal and the systems are expensive.
In order to get a boat that is efficient enough for even modest electric or hybrid is almost always a start from scratch build with a long waterline and narrow beam. Look for a long, skinny displacement hull or a catamaran.

I looked into a hybrid as a neat idea but I build things and the numbers just did not add up to pulling the trigger. I all comes down to what you deem as acceptable ROI. Resale will be very low.
The costs are staggering and the performance too marginal for most peoples needs.
I look at the idea like the impossible triangle. Easy to draw and imagine but near impossible to build anything practical.

 

[Pascall]

https://zeroemissionservices.nl/en/itg-nedcargo-zes-accelerate-sustainability-of-inland-shipping/

In the Netherlands, several commercial ships sail electrically, but it is expensive and the infrastructure needs to be adapted.
Greeting

Pascal.

 

[Gdavid]

I remember a thread started by a poster with the same aspirations several years ago. I think he had a Gulf Star 36. His postings came to a halt so I don't know if he found the task insurmountable ,found the cost prohibitive or what but I do know lots of people have the same dream of converting an old boat to electric or hybrid but have never known of anyone's plans to come to fruition.

I recall that project and wish they owner had an update for us. I think the gulfstar is a pretty candidate, while true-full displacement recreational trawlers are pretty rare, and even fewer in a twin engine application, the gulfstar motor yacht hulls appeared very heavily influenced by their sail-driven siblings and there are also plenty languishing in boat yards

The battery costs for such a project has come down dramatically over the past 2 years, the OP of this thread should be able to make a good conversion is the electric drive motors can be sourced reasonably. I would set it up like a true electric drive, similar to a locomotive or diesel electric tug rather than a Toyota synergy drive or the Green line boats. Easier to configure the system and replace components that way.

 

[twistedtree]

https://zeroemissionservices.nl/en/itg-nedcargo-zes-accelerate-sustainability-of-inland-shipping/

In the Netherlands, several commercial ships sail electrically, but it is expensive and the infrastructure needs to be adapted.
Greeting

Pascal.

That's an interesting approach they have taken with shipping container batteries that can be swapped for a charged container at various "refueling" stations. I recall an electric ferry in Norway where they also swap batteries while the ferry is loading and unloading, and the batteries are recharged on land while the ferry is in transit.

Some time ago in early EV days, one company, perhaps even Tesla, was promoting a similar approach. Battery packs would be standardized and "gas" stations would just swap battery packs. Obviously that didn't materialize.

 

[Mac G]

I think Cigarette makes an electric model.

Back in the 1970s I had a summer job in a commercial tugboat shipyard.
Many of their harbor tugs were diesel electric.
Was amazed that an electric motor actually drove those things but the advantage for a harbor tug was being able to go from full forward to full reverse quickly without having a conventional transmission to mesh and mess with.
Electric motors are fast and responsive.
The diesel engine produced the electricity.

I think the post suggesting a catamaran makes sense as would be sleeker and faster on the waterline plus offers all that space between the hulls for the enormous batteries required.

A diesel genset to charge the batteries would make sense, but have no idea how long that might take or where and what size that fuel tank would have to be.

Very interesting project indeed.

 

[O C Diver]

While I have very little experience with electric boats, the one takeaway I found from owning a 3 HP outboard for a 10' dinghy was that power required grows exorbitantly after any hull wake and increase in hull length. Running my dinghy below 3 knots gave a range of 30+ miles. Exceeding 3 knots about cut it in half. Very interested to see what a 50' vessel consumes and if it can be run at 6 or 7 knots.

Ted

 

[twistedtree]

While I have very little experience with electric boats, the one takeaway I found from owning a 3 HP outboard for a 10' dinghy was that power required grows exorbitantly after any hull wake and increase in hull length. Running my dinghy below 3 knots gave a range of 30+ miles. Exceeding 3 knots about cut it in half. Very interested to see what a 50' vessel consumes and if it can be run at 6 or 7 knots.

Ted

A quick check with a prop calculator says it will take 25hp to move a 50' lwl, 16' beam boat at 6kts. I also used a very favorable 50,000 lbs displacement.

25 hp is a little over 18kw. 4hrs cruise time will consume 72kwh. Based on that I'm probably design for a 100kwh battery bank to allow reserve for weather and sea conditions. Recharging 72kwh from shore power, using about 80% of the rated shore power, would take 7-8 hrs for a 50A 240V outlet, and about 25hrs on a 30A 120V outlet.

But that's for pure plug-in electric, and this is to be a hybrid. I'll assume it's a parallel hybrid since that's really the only thing that makes sense for a boat. You would run on electric that you obtained and stored from solar, or from shore power, presumably renewable shore power, not coal shore power. Then once depleted you would switch over to direct diesel propulsion.

Although you could run a diesel to recharge the batteries, that is less efficient that using the diesel directly for propulsion because of conversion losses. This is why a serial hybrid doesn't make sense for a boat.

And a diesel electric doesn't make sense either. Yes, it's used for locomotives and tugs, but as Mac G pointed out, that's done for it's power transmission qualities and is at the expense of efficiency, not to gain efficiency. There are some efficiency gains for tugs, but it's specific to their very unique power requirements. When tugging, they have very high power requirements, yet when repositioning they have much lower requirements. Diesel electric allows them to run a giant engine only while tugging, and run a much smaller engine when repositioning.

 

[Pascall]

I think most people are surprised how many ships are diesel/electrically powered.
In the 1960s, ferries in the Netherlands were already designed in this way, but all passenger ships are now diesel/eclectic.
A big advantage is that you can use several small diesel engines/generators and switch to the required power.
The option to place it in a (random) place in the ship also plays a major role in the choice of diesel/electric.

Greeting

Pascal.

 

[O C Diver]

A quick check with a prop calculator says it will take 25hp to move a 50' lwl, 16' beam boat at 6kts. I also used a very favorable 50,000 lbs displacement.

25 hp is a little over 18kw. 4hrs cruise time will consume 72kwh. Based on that I'm probably design for a 100kwh battery bank to allow reserve for weather and sea conditions. Recharging 72kwh from shore power, using about 80% of the rated shore power, would take 7-8 hrs for a 50A 240V outlet, and about 25hrs on a 30A 120V outlet.

But that's for pure plug-in electric, and this is to be a hybrid. I'll assume it's a parallel hybrid since that's really the only thing that makes sense for a boat. You would run on electric that you obtained and stored from solar, or from shore power, presumably renewable shore power, not coal shore power. Then once depleted you would switch over to direct diesel propulsion.

Although you could run a diesel to recharge the batteries, that is less efficient that using the diesel directly for propulsion because of conversion losses. This is why a serial hybrid doesn't make sense for a boat.

And a diesel electric doesn't make sense either. Yes, it's used for locomotives and tugs, but as Mac G pointed out, that's done for it's power transmission qualities and is at the expense of efficiency, not to gain efficiency. There are some efficiency gains for tugs, but it's specific to their very unique power requirements. When tugging, they have very high power requirements, yet when repositioning they have much lower requirements. Diesel electric allows them to run a giant engine only while tugging, and run a much smaller engine when repositioning.

I would guess your numbers are pretty good with required HP. My 43' lwl boat with a sub 50K displacement requires 1.2 GPH (24 HP +/-) to move the boat at 6 knots with normal electrical loads other than air conditioning.

Certainly using a repurposed hull instead of an optimized one, will have a moderate impact. Depending on the boat, removing all that weight may generate a stability concern. Finally, Depending on the original design speed and propeller size, steering may be a bit of an issue if the rudders are planing hull small.

Ted

 

[Shaunc]

I am looking to purchase a laid up, two engine, Trawler, not a Salvage Vessel, about 50 ft. I am working on converting an older vessel to a Plug-in Hybrid. I will need to remove the engines and genset and replace them with the Hybrid power train, high capacity Lithium batteries, control system, inverters. i am in Southwest Florida, but will travel for the right vessel.

I know of someone who has one on the hard at glades boat storage near Moorehaven.


The boat was rough but I believe they intended to do something similar but never got it going.

 

[Kit_L]

I am joining to add a comment or two. 50' is a good displacement length, I feel, because that length's hull speed is about 9.5kn, and an efficient speed is around 7.5 (S/L 1.1). I made these calculation on a waterline length of 50'.

None of the electric-only vessels I have seen so far (all expensive cats) have been able to do more than 5kn for time using what is harvested from the sun, even with all roof space covered in efficient panels. I think a parallel hybrid vessel makes a lot of sense, and I am very interested in the discussion.

 

[Barrie]

This is my old boat. Does about 4 knots at best. The link will give you more detail.

https://plugboats.com/vote-for-the-...in-the-2023-gussies-awards/#jp-carousel-27933

 

[delirious duo]

maybe try from a bare hull. Saves removing **** from the boat. This not my *yard decoration* lol. I’m never sure why people think this is a good idea in a vessel who’s load and demands don’t change like tugs and commercial vessels. Just my opinion but it seems like mass work for just a more complicated boat.

https://portland.craigslist.org/nco/boa/d/chinook-50-super-econo-navy-hull/7719818684.html

 

[SteveandZoila]

What seems left out of this plan is: How much electrical power you need for other stuff. I have solar, but its all going to house bank for all the stuff I have running.Could be 300 or more Amp hrs a night. Where are you going to get that if you deplete your batteries for propulsion?? Oh yes, Sun didn't shine much the last 2 months in the Keys.

 

[Hybrid1]

A very good point. In my configuration, the battery packs will provide enough capacity for the House load for 24 hrs. When cruising on the diesels, the electric motors act as generators to recharge the battery banks in about 1 hour. I will also have a solar panel configuration and be able to connect to shore power when docked.

 

[Hybrid1]

If possible, I would like to know more about the vessel. On the surface it seems as if might be good fit. Would it be possible to talk with the owner and find out more.
thanks

 

[Hybrid1]

Thanks for the lead. Is there any chance you could put me in contact with the Owner?