Electric tug under design and to be built

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For those who are interested in electric propulsion.From an article in Work Boat magazine. Don't know if the link will work, text copy / pasted below.

https://www.workboat.com/shipbuildi...U4-y1UoC8gX53BUoeLRKDky29BO7Dc8OifQQfyyH35sA*

Elliott Bay Design Group (EBDG) and Miller Marine announced in November that the two companies would design and build a fully electric truckable push tug.*

The 26' tug is purposefully designed as a multifunctional utility boat servicing marine construction sites, tending dredges, tending buoys, short range ferry operations and other near shore operations such as crew transportation or line handling, EBDG said. The tug will be a test case to understand the market demand for an all-electric vessel.

Miller Marine, a boat building and steel fabrication company based in Deltaville, Va., builds assorted workboats and passenger vessels. Seattle-based EBDG is a naval architecture company that has been in business for 36 years. They have designed vessels ranging from 20' to 700'.*

A request for designing an electric truckable tug

Last year, Miller Marine reached out to EBDG to discuss partnering on development of a battery-electric option for Miller's popular truckable tug design.

Knowing that EBDG had experience with designing hybrid-electric ferries, Miller Marine saw a market opportunity for an electric version of a truckable tug design they had been building for several years — a result of new EPA regulations and government grants for zero and low emission vessel construction. Also, other states are starting to follow California’s lead in giving credit to low-emission or zero-emission operations, making the use of electric tugs more desirable.*

An industry-first electric tugboat

For EBDG, the new electric tug is another significant step in its goal to become market leaders of green and alternate fuel technologies, as well as an industry-first and test case to understand the market demand for an all-electric option that operates differently than a diesel tug. The electric tug will be built in an inland style with a lot of room in the hull for batteries. EBDG will incorporate an electrical propulsion system into Miller Marine's truckable tug design. Once the design phase is complete, Miller Marine will build the vessel at its 15,000-sq.-ft. production facility.

Designing electric or hybrid vessels is a bigger and more complex design challenge, said Mike Complita of EBDG. “Although the hull itself is easily adapted to an all-electric option, the biggest challenge is to work with multiple smaller component providers who don’t offer a complete integrated solution, which means picking each component individually and ensuring everything communicates together properly and effectively,” he said.

One example is proprietary shore power plugs, which are being developed by several companies and must be treated differently than land-based applications.*

Design phase and production roadmap

EBDG’s primary 3D design tool is Rhino, which integrates with AutoCAD. Other software tools used by EBDG are Navisworks and ShipConstructor for reviewing and performing structural analysis.*

The tug is made up of two pieces — a shoe box-looking hull and a customizable superstructure with an enclosed steering station. Both pieces can be loaded separately on a single flatbed trailer and towed anywhere in the U.S. without the need for any special permitting or road closures. EBDG is currently working with vendors to select the tug's components and equipment. Construction is scheduled to begin in the summer with the first tug completed and put in operation by the first quarter of 2024.

Size and configuration details

The 26' vessel will be powered by two permanent magnet motors with a total power of over 300 kW (400 hp). The new tug will not only be truckable, but 26' is also the cutoff for Subchapter M oversight by the Coast Guard.*

Shore power will be used to recharge the vessel's battery banks overnight, taking*about eight hours. On a full charge, the vessel will operate with contingency for 12-plus hours. A closed-loop fluid cooling system will provide temperature control of the batteries, motors and electronics, maximizing their lifetime. This configuration is ideally suited for shallow and silty water operations, EBDG said.

The future for electric tugboats is looking bright

The electric tug is designed to support public agency and private enterprise marine construction operations and short-range logistics, with dredging being a key market. Dredging that requires truckable tugs is typical in a port or near-shore body of water. Thus, the customer doesn’t have to go far out to do dredging work so they can come back and charge at night. An in-port application would provide access to electrical recharging power at the shore. “This tug also offers customers the option to truck it into landlocked sites instead of building it on site and having it stuck there,” said Complita.*

In the next two years, a similar type of electric boat designed for fleeting operations will hit the water. This fleeting boat scales the current design up about three to four times to create a giant raft of barges that are pushed down a river by a larger tug with long-range capability. The new fleeting boat design will provide a zero emission option to manage individual barges.

Screenshot_20230214-075058_Firefox.jpg
 
I wonder what capacity the batteries will have? Article does not mention. It does say 400 hp and 12 hours duration, if combined that means 3.8 mega watt hours or about 50 Tesla long range batteries (or 3200 Battleborn 12V). They also mention 8 hours recharge time, with that battery would require 1000 amps @ 480V.
 
Obviously the 12 hour battery life is not at 400 hp continuously, but I get your point.

Many such new EV applications work that way. Just like the electric RV that needs recharging every 80 miles.

They all sound good at first, then reality sets in.

David
 
I wonder what capacity the batteries will have? Article does not mention. It does say 400 hp and 12 hours duration, if combined that means 3.8 mega watt hours or about 50 Tesla long range batteries (or 3200 Battleborn 12V). They also mention 8 hours recharge time, with that battery would require 1000 amps @ 480V.
The article is very short on technical details. As you estimate it's going to require quite a charging system. Part of the lacking tech details. I will suggest that the nature of the work this tug is being designed for won't require 400 HP continuous. It will interesting to see the final design and eventual build.
 
One of the interesting aspects of the charging station is that it will likely allow bi-directional flow. If you have a big battery sitting idle it can generate a revenue stream while connected to the grid.

Electric seems like a natural fit for a lot of fleeting and harbor tugs that are tied up a lot of the time.
 
The article is very short on technical details. As you estimate it's going to require quite a charging system. Part of the lacking tech details. I will suggest that the nature of the work this tug is being designed for won't require 400 HP continuous. It will interesting to see the final design and eventual build.

Puttering around a harbor and occasionally giving a 400 hp shove, this could be viable. That is similar to a Tesla, 600 hp momentarily but 20 hp continuously. Now hitch that tug to a log boom and run it the length of SE AK - I don't think so, though routine for diesel. Autos need a very small percentage of peak power most of the time, which makes electric just becoming viable. Long haul trucks, aircraft, trawlers may use 60 - 80% power continuously. Now electric has a capacity problem. This is why most electric cars can do 0-60 in 3 seconds, but can't even tow a light trailer. It isn't just battery capacity either: the motors, motor controllers, and batteries overheat, just not in 3 seconds.
 
Humm, two 1,000 kw onboard backup generators.

For a harbor tug it still makes sense I think. You size the generators for average demand and let the batteries cover the peaks and low power periods. That should let you extract optimal efficiency from the generators and electric drive gets rid of the need for controllable pitch props and such to optimize thrust for the wide range of operating loads a tug sees.
 
RSL
The design criteria says the gensets will only be needed a few times per year. Brian’s link is worth reading
 
I get the sense that large electric pods are used on a variety of boats these days. Maybe subbing in batteries for large diesel generator(s) isn't the hard part. The shore side facility is a big project.

There are a lot of moving parts. The port may benefit from having a couple of MW on tap, like now as a cyclone bears down. As I mentioned earlier, a big battery can be used for peak load grid management.
 
I attended a seminar on electric propulsion several years ago. I'm sure battery technology has evolved since then as there is incentive for funding battery research.
One example given was a harbor tug. Never went too far, worked regular hours, the work cycle lent itself to recharging, etc. The cost curves between the diesel and the electric tugs favored the electric tug...until it came time to replace the batteries. Then the cost curve was all shot to hell.

That was several years ago and battery technology is moving at a very rapid pace. As the technology and capacity come online cost should come down. I doubt those curves would be similar today.

A good example is the Gee's Bend Ferry in Alabama. Link below from Workboat is from 2020 about the 1 year anniversary of operation. Again, the operational criteria was within the envelope of the driveline cycle. Short run, opportunity the recharge, never went further than across the river. Part of why this worked 4 years ago is how this was funded:

"The $1.8 million project was funded in part with a $1.09 million Environmental Protection Agency (EPA) Diesel Emissions Reduction Act (DERA) grant. The state kicked in the rest."

:socool:

https://www.workboat.com/passenger-vessels/first-all-electric-ferry-in-u-s-reaches-milestone
 
I understand there is development of an electric ferry which runs from Anacortes to Gumes island. Haven't checked on it lately but did look into the program a year ago. Lot's of infrastructure required at the Anacortes end and it didn't seem cost effective, but they were going to give it a go.
 
It isn’t clear what problem this means of propulsion is trying to solve. A solution in search of a problem?
 
I understand there is development of an electric ferry which runs from Anacortes to Gumes island. Haven't checked on it lately but did look into the program a year ago. Lot's of infrastructure required at the Anacortes end and it didn't seem cost effective, but they were going to give it a go.

The plan is for one to be funded by 2025 for Guemes Island, which is a very short cross channel hop from Anacortes.
Our "illustrious" CiC, aka "where's Joe?" is pushing for one north of there on Lummi Island, that most residents are just shaking their heads in wonder about.
 
It is the same issue for electric cars. It would be nice if it simply helped the planet but sadly, it creates a host of new problems. Standard Li-ion requires critical elements Lithium, cobalt, manganese and graphite.
Mining is often done in 2nd or 3rd world countries with slave labor and the reckless excavating rapes the land with no regard for the local landscape. Search any web space on "hidden cost of cobalt mining" for starters.
As the first wave of electric cars begin aging out, imagine the mountain of thousand pound batteries and the challenge of recycling.
Teslas and the like are significantly heavier than ICE cars such that car-carrying trucks are incapable of hauling them and they're creating weight concerns for bridges, overpasses and multi-story garages... and I haven't even mentioned growing strain on the national power grids... oops i just did.
I'm not a curmudgeon that wants to burn fossil fuels forever... I just mean that as an engineer I don't yet believe batteries are a long term solution. just my .02
 
...Teslas and the like are significantly heavier than ICE cars such that car-carrying trucks are incapable of hauling them and they're creating weight concerns for bridges, overpasses and multi-story garages...

A Tesla weighs less than a Dodge Charger, an F-150 or a Chevy Tahoe.
 
Rudolphs Diesel and the energy density inherent with liquid hydro carbon fuels aren’t going away. At the same time, smart people are making great strides with other technologies. The average age on this forum is about 65 years old I would guess. It may make for good internet banter, but the reality is our opinions are irrelevant on this subject. Younger people and future generations will decide how this plays out, not us. BTW, complaining about oil companies and their “profiteering” is a bit rich coming from people who have such strong opinions on anything green. Big oil has been hammered and their stock prices have been in the dumps for years, until recently when things finally turned for them. They are returning a lot of their cash back to shareholders and provide good jobs for many people for a fluid that we need for every day life and the products we use. Funny to hear people complain about paying $5/gal for a refined product when a 12 oz can of pop costs a couple bucks.
 
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I'd guess that this is just the trucking industry seeing an opportunity to have their load limits increased so they can carry more weight and make more money. No one seemed concerned about the weight of Cadillac Escalades, Hummers or other large heavy vehicles that have been sold for years. Why would EV's suddenly be a problem ?
 
Over 75% of the world’s population live in areas that are short on electrical power generation and reliable grid systems. Moving from oil fueled vehicles to EVs recharged by fossil fuels is palliative only.for this 75%.

Until nuclear power and clean coal technology are widely embraced only us yacht and heavily subsidized EV owners can afford a Tesla or Lightning pickup. Then enter the EV need for an additional 500 or so pounds of various metals as compared to a non EV vehicle.

Thus more power is required to produce these presumed justifiable EV metals. The overall power requirements to build, operate and maintain an EV worldwide fleet are intentionally obfuscated by governments and “us guys.”

Windmill and solar generation worldwide growth is more than matched by coal and gas growth. Why? Too many new bodies demanding and needing electricity to meet basic needs.

So how do we really reduce fossil fuel requirements? Mother Nature does it by thinning the herd.
 
A Tesla weighs less than a Dodge Charger, an F-150 or a Chevy Tahoe.

Actually this statement is false for three of the four Teslas in production.
Tesla Model X = 4,555 lbs
Model X = 5,185 to 5,390 lbs
Model S = 4,561 to 4,766 lbs

But hey F-series trucks brings up a good point, let's compare apples to apples

Standard Ford F-150 = 4,021 to 5,014 lbs
F-150 Lightning EV = 6,500 lbs
In the lightning, the battery alone weighs a whopping 1800 lbs, yikes(!)

Anyway, I should know better than to weigh in on a controversial topic. Didn't mean to ruffle anything, i'll probably let this thread alone now... ;)
 
Actually this statement is false for three of the four Teslas in production.
Tesla Model X = 4,555 lbs
Model X = 5,185 to 5,390 lbs
Model S = 4,561 to 4,766 lbs

But hey F-series trucks brings up a good point, let's compare apples to apples

Standard Ford F-150 = 4,021 to 5,014 lbs
F-150 Lightning EV = 6,500 lbs
In the lightning, the battery alone weighs a whopping 1800 lbs, yikes(!)

Anyway, I should know better than to weigh in on a controversial topic. Didn't mean to ruffle anything, i'll probably let this thread alone now... ;)
Actually you list 2 different weights for the Model X and Model Y tops out at 4416 lbs if that's what you meant.
A fully optioned F150 weighs closer to 5800 lbs wet. Source: Car&Driver 2023 F150 Specs
I think of the Lightning as the most fully optioned F150, sort of like earlier Lightnings.
 
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A fully optioned F150 weighs closer to 5800 lbs wet.


And the newer F-150s are somewhat lighter than they used to be as well. The switch to aluminum body panels a few years ago saved a few hundred pounds compared to the previous steel body.


The more capable EVs are heavy, but they're not insanely heavy compared to some other similar vehicles.
 
Last year we bought a new F150 gas powered. The weight is listed as 5650 lbs. An equivalent Lightning weighs in at 6500 lbs. The Lightning is an amazing vehicle with the latest Motor Trend calling it their "Truck of the Year." This magazine issue is worth getting your hands on if you're considering buying a pickup and can afford the wait and 40% or so price premium.

Of note, Ford has temporarily shut down the Lightning production line as they root out a battery/electrical fire that occurred with a recently built and still in the too be shipped line. Also Chrysler says don't park your Cummins diesel pickup in the garage until they figure out a remedy for wiring harness fires.
 
Been reading about the U.S. rail road system it decimated the horse based teamster industry and made cowboys nearly unnecessary for cattle drives. Changed infrastructure greatly with towns and even cities appearing and disappearing. Totally changed agriculture and industry.
People talk about the infrastructure needed for EV In comparison to RR and the interstate road system proportional not as biggy.
 
Changes in infrastructure at the end of the 19th century were a whole different thing. Driven by monopolies and unrestricted by any regulation. Cannot be duplicated today.

You should not hold your breath waiting for quick charge infrastructure to be ubiquitous in marinas for your electric trawler. You will turn blue and die.
 
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