Diesel Electric Propulsion

It will come in more yachts, as we have seen in a number of recent megayachts built or under construction. With pods or straight axles for less draft.

Eventually the fuel cells will be a part of the power generation. Nice and silent.

It's ironic you should ask. I'm currently writing a a 40 page / 120 hour feasability study for a major transportation manufacturer on this very subject. In answer to your question... YES.

The steerable podded propulsor provides the greatest potential due to favorable hydrodynamics and control, while being competitive with conventional propulsion systems.

The benefits of diesel electrific propulsion (podded) are many...

1. Integrated electric power and propulsion systems enable design flexibility and save space, by eliminating gear trains and propeller shafts.

2. Hydrocoustic dampening is increased by eliminating the mechanical link between the power plant and the propeller. Essentially, electric drives will enable the reduction of noise and vibration.

3. Improved operational flexibility and reliability. With a diesel electric power-station concept, power is supplied by a set of primary gensets that provide power to propulsion and other designated loads. This approach provides the flexibility to shift power between propulsion, onboard services, and other electrical loads. It also enables improved speed control and maneuverability over conventional propellor and rudder configurations. Pods can rotate 360 degrees for directional thrust, eliminating thrusters.

4. Increased space. Eliminating gears and shafts from the propulsion system will make more space available for other uses. Also, the primary power (engines) will no longer be tied to the propeller shaft line, so the gensets can be distributed to more idealistic locations throughout the yacht, i.e. more favorable C.G. locations.

6. Reduced Crew. Due to digital control and automation, which will be an integral part of the yachts electrification, the requirements for additional engineering staff are reduced.

7. Reduced logistics. Common power and propulsion modules can be used across a variety of hull types and model lines.

8. Reduced costs. Commercial technology is likely to be available for many of the system elements.

9. Life-cycle cost. Overall operational efficiency is greatly improved as electric motors are able to sustain higher RPM's with less maintenance throughout their operational parameters.

10. Redundancy. Instead of one or two primary engine sources, multiple gensets can be utilized, both on-line and off-line, as power is needed. If one fails or is down for maintenance, the other gensets can provide power to the propulsors as needed.

11. Fuel-consumption savings. The diesel electric concept has been proven over a wide range of applications, from trains to ships, as a more economical source of propulsion.

I could continue, but you are probably falling asleep by now...

This reminds me.......

of a thread I started on 23 Sept last, then called "total energy plan"!
maybe Carl should integrate these 2, same subject.
Perhaps my title was not all-too-clear, lack of fluidity in English
But this type of solution will come, whatever the title, and it will come fast.
Fuel's getting too expensive, even for the zillionnaires; why else would they travel 1000's of miles out of their way to bunker cheap fuel in Malta or Gibraltar? (That's our part of the known world, Carl!)

The negative points?

I like this discussion, because this is the way this conservative industry will go forward!

And this is perhaps the first and one of the major negative points: this industry is conservative! Like the aircraft industry (untill Airbus installed fly-by-wire!)
Maybe it just takes someone to do it in a logical way, on a medium-sized yacht.
Second negative fact is of course that the overall installation will become more complicated, suffice to draw a complete functional flow chart analysis.
Third may be the resistance of propulsion engines manufacturers. They can and will influence their (not always so knowledgable) clients to stick with the known-and-trusted technology.
The yards (unless they build on spec and with courage) will probable not want to experiment, and after all the client decides.

Conclusion: there may be much more reasons found against DE, it's easier to find negative arguments than positive!

I think the engine manufacturers have no objections to diesel electric propulsions since most of them already make gensets, it is just a matter of transition.

To lift the pods is an intriguing thought, however they are very heavy, needs to be fixed with heavy-duty stuff to the hull and in general needs very little maintenance. Remember, they are used in ferrys in daily traffic all year round.

The sound effect is nothing to worry about on big yachts, where you should hear little or nothing if well built.

So in general, I think the DE systems will take over step by step and going down in size of yachts as well.

For lifting azimuth pods go to schottel.com
I guess Lars is right for the sound.
Vrooooooooooooooooom is for the fast show-offs.
Most yachts of interest are slow with very silent engines anyhow.
That's it for the week guys,
Ciao

it's coming

Diesel-electric, or total energy plan, or whatever you call it, it's coming, it's here!
After the 50M Benetti with her ABB Azipod electric drives, I just received information about a 75ft (powercat of course) with diesel-electric as a straightforward option, printed in clear in the brochure!
Go to teamboat.fr
She's call Galileo 75 - Voyager.

On an even smaller level Bavaria and Panda Fisher have worked out an electric version of a 47ft monohull saling yacht and Fountaine-Pajot, the french sailing cat builder, proposes electric versions.

Professional BoatBuilder article

The Dec/Jan 2005 issue of Professional BoatBuilder has a really excellent article on the subject of diesel-electric propulsion by Nigel Calder

alternative propulsion

would be a broader denominator.
D/E is fine, well known but hydraulic propellor-drives are an alternative solution.
Someone, someday will have to shake up this (our) sleepy and ultra-conservative industry!
One is certain: 2 big diesels to drive propellers only during an infinite percentage of the lifetime of any boat is madness, old fashioned and will be overruled shortly!
Please prove me wrong. That way the (r)evolution will take place.

I have read the other postings on this topic and yes it has potential, my concern for all of the benefits is from a safety perspective. Stored charged energy units (batteries) in standby mode can very well discharge, and especially in colder climes may tend to expand when recharged, potentially causing a fire or an explosion within the battery cores. Particularly in a damp marine environment. This alternate approach could well demand conditioned engine rooms at more stable environmental constraints that currently available and getting the cooling must come from sokmewhere.What are the long term storage issues when going through constant charging cycles? Anybody worked specifically on this issue?

Also: Has anyone come up with an optimized engine room design for a single engine terawler say with a 30ft beam? ANY inputs on this topic would be of interest. One reads quite abit about how well an engine room looks but very liottle about how functional the engine room is for maintenance or rebuilds at sea if required..

Most of the Engine-Room designers build their engine-rooms whitout ever having worked in one for a longer period of time, let alone rebuild an engine in one at sea or at a dock (not a dry-dock). The same goes for interior- and exterior designers, ... well basically most of the designers... You do not always hear or read about them, but they are out there....

That is why the most successfull yachts are built by owners and craftsmen who have actually lived and worked aboard large vessels.

I for one have a big interest in yachting, motors and ICT which means I am enthousiastic, but look at everything in a logical way. Not going from A to C without passing via B.

If I take a detailled look on how 99% of the yachts are equipped for Multi-media and Telecom, it is hilarious. Most designers think that because they slap in a big-screen plasma they have created a high-quality media-room. If you look at where the speakers are mounted it says enough. Even the location of the screen itself often says enough of the planning, most (and I really mean most) are mounted so that the sun will always reflect into the screen, especially at sea where you not only have top-light from the sun, but also reflecting glare from the water. Ceiling-mounted speakers are a bad idea for quality, especially on a yacht that has giant vibrating diesels on board creating 1000 - 1500 Hz resonances throughout the structure. let this frequency now be smack in the middle of where most conversation is replayed on a movie, TV. you won't hear the noise, but if you would listen to the same move in a solid structure with descent floor-standing speakers you would notice the different worlds of quality. even if they use the same amplifier, player, ...

The same goes for the engine-rooms. I have seen pictures and layouts of engine-rooms that really look nice, untill you have to do something in them. An absolute nightmare. A technique not used on yachts, but found in every single diesel car is to use a swirling air-intake so that the air creates a small vortex within the combustion chamber to get more air in at the same time with less noise and a stronger better combustion asa a result.

Why this isn't done ?

Simpel : The money is there for fuel and big-cube engines anyway.
Why generate more power from smaller engines while a slightly bigger one will easily sell as "more solid". take a look at modern diesel-cars. Who whould have imagined a 330 bhp diesel car 5 yrs ago ?
Why spend days and weeks of carefull planning on something invisible as the engine-room. it is not the owner that will spend his time in there, it is the crew. Do we built the boat for the crew? Nope, it is being built for the owner... it is sad to say, but I fear this is a well known fact. The only places in the yachting industry is in the hard-core racing yachts/boats. There everything must be strong, light, reliable and easy to maintain. Eventually some things will filter down from "racing-technology" into "common-technology" but this most of the time does take years, many many years...

Take a detailled look at loads of engine-bays and imagine what would happen in the case of a fire. Scary.

I must admit, this is all judges upon what I have seen and learned from video- and foto - coverages and visiting a few yachts (7 to be exact, ranged between 47 to 118 ft). But these yachts and captains where all about how well sorted it was. Now if I, a non-engine-room designer, can easily imagine a better and safer world, then why don't most of the designers really invest some time in it. It will definitly profit them in the long run, even in the short-run if they play their cards right.

Regarding battery-storage on yachts : All batteries are monitored (or definitly should be) on acid levels and pressure levels within the battery and casings. It is a well known fact that when the acid-gradient rises to high, vapours will be formed (lethal ones that is) and pressure builds up within the battery the point of explosion. This is a rather slow process and goes together with slowly reduced capacity and performance of the batteries. A good indicator to check the health of them.

Ok, and I agree, so what is your solution to engine bay design?
As for batteries, I submit there is a greater risk with a short circuit when recharging the battery stack .

Well, have persons involved that actually have rebuild engines at sea and have worked on larger vessels for longer periods of time where not everything went as supposed to.

Modern technology allows to build a complete virtual 3D tour of the vessel before even one sheet of metal is cut or ordered. Have those images looked at and investigated by experienced people would be a better way. Take the new London Heatrow terminal 5 building as an example. Only after re-investigating and re-creating the 3D images they found out that the walking escalators would have to be build inside the terminal or that the terminal design-phase needed to be altered. Otherwise there was no way that they could place the walkways and escalators. Now and we are talking of the biggest airport-buildings being constructed in the last few years and with a very high level of architectural skill on board the project. Why not repeat it in the yachting industry.

The current designers use this already for interior and exterioir designing and hydro-dynamic testing, why not extend it just that little bit further. Most of the time complex situations need the simplest of solutions, but youmay need to look at it from a different viewpoint.

THAT should be the real talent of a succesfull designer / architect. And history has proven this over and over again.

The best idea's are generated when under pressure, so people that needed to perform ordinary tasks at out-of-the-ordinary places or times are the best sources of experience.

IMHO it all boiles down to experience with working in and on boats and later having evolved in designing them. I don't know how many of the current designers have actually this type of people on their team, but they should be considered absolutely key. And obviously this is not just for the engine-room design, but goes for every aspect of yachting.

As I have lived onboard a couple of yachts for five years, worked as a hands-on captain and also as a yacht broker, now designing yachts I am glad you asked...

Unfortunately you are right about the problems with bad designs. Many buyers are not very experienced and if the yacht brokers should know and tell them the full truth on what is behind some of the glossy exteriors, many yachts would remain unsold...

This can be a long story, but to keep it short I´ll start with the initial problem that a custom made boat is designed and built from scratch every time. Can you imagine that with a car or an airplane? The chance of mistakes when you put together a new team and new techniques and new materials and the most recent equipment? And each time the yacht gets bigger and the expectations grew and more new ideas (like electric pods) and gadgets are incorporated.

We used to say that an average yacht, 100-150 feet included 2.000 drawings!

Next problem is what you are pointing at, the lack of hands-on experience. Not only the designers but also the engineers and the boat builders have very limited experience of the day-to-day life on a boat at sea or in port and what the crew have to do to keep it floating, alive and shining.

The idea of making a useful and realistic 3-D rendering of the engine room would probably cost more than building it, since there are so many fittings, tubes and wires that you would need a committe of people fighting around the computer. It is probably too complex to achieve since as I said, there are always new equipment you have sometimes not even seen before it arrives.

There are many more design errors and blunders made on yachts because of sheer ignorance. Things that will cost in terms of more expensive construction and maintenance, more crew needed, perhaps less good working and living environment leading to less good crew and finally you just want to replace the yacht. Some people say this is what keeps the industry busy, but in worst case people will also give up yachting.

But, there are solutions. A good yacht broker would help the unexperienced buyer to put together a team prior to construction. What you need early on is a project manager and a captain. It can be the same person. They can together with the designer/-s and the owner decide on all the aspects and desires of the dreamyacht so that nothing is left aside that later end up as a compromise. They will together select the best (for this project) shipyard and follow the construction on site, so that there is always someone that can answer to problems, make solutions and take decisions.

As I said, this story could be very long but there are people out there who united can get you a very good yacht. And it happens every day

Back to DE please!

Hi,

Although I extremely appreciate and support the last replies, the initial subject was Diesel Electric propulsion.
Can we get back to that?

Whereas brokers are concerned, I think this would make a nice, funny but acid separate thread!

OK. The original point in my bringing out the safety and engine room issue is simnply, the environmental consraints to deisel electric power generation support is one aspect no one speaks of. It seems to be the case that unlimited funds will always produce wastefull unlimited design. True design takes into account efficiency which includes environmental maintenance, not in terms of polluting the environment, but in terms of the engineering environmental effects. So what is achievable and what is doable versus what is prudent, must all be taken into account not just I want x performance and I have unlimited resources to achiev it. In terms of design, the new volvo approach with forward facing props is packaged very well. I would like to see Diesel/Electric put as much thought into efficiency.

A very interesting thread - fuel prices will never be as low as they are right now, in terms of oil wars, global warming and the PeakOil scenario, so what will happen when it reaches USD100, USD200 or USD500 a barrel? USD1000??
It makes sense that the super-wealthy will continue to ply the oceans after the wells have run dry, so how will they do it??

Bear in mind that most plastics will also become very expensive as time goes by, as plastics are petro-derivatives. Epoxies, vinylesters, foams, fillers and fibres would become ever-more expensive....................(one would think that hardly possible )

Will wooden sailing vessels return to being state-of-the-art?? Who knows.........

I think that for a good while biodiesel will offer a decent alternative, there may even be biodiesel powered craft out there already. A rather pleasant alternative, if emissions and sustainability are taken into account.

Hydrogen will never present a real alternative, because hydrogen is an energy carrier, not an energy source. This is because it costs more energy to extract hydrogen from whatever compound it is taken from (usually methane, I believe); than it yields as a fuel.

Photo-voltaic arrays are a good plan for house power, but I doubt their abilities to supply the kind of grunt required for main propulsion........but I would suggest one moves on that quickly, because most PV panels are heavily plastics-dependent and will become more and more costly as oil becomes dearer.

A very interesting option would be a hybrid system, primarily powered by sail and with something like the electric wheel as an auxiliary power plant.

I think DE will be used as a short term solution on a few vessels, but the really interesting stuff will be what the military are planning to do and the spinoff from there to the yacht industry.

It stands to reason that the military will become ever-more nuclear oriented, and so the conservative yachting industry ( perhaps the conservatism is because of the military connections that have for ever linked the two industries??) will almost certainly be able to offer a prospective customer one of two options in the medium term (25 to 50 year) future - sail or nuclear......................

Who would want to be a Chief Eng in 50 years time???