Complexity vs mission-worthiness and reliability

The friendliest place on the web for anyone who enjoys boating.
If you have answers, please help by responding to the unanswered posts.

Gilhooley

Veteran Member
Joined
Sep 21, 2014
Messages
70
Location
Greenland
Greetings..

After 10 years, I’m in the process of selling my Nordic Tug 42 and doing that 100% myself for reasons that would not be interesting in a power forum. You have to, at a minimum message a product you’re intending to sell and for me that is easy... the clear value of a low-complexity/purely mechanically controlled diesel. My 6CT and the resulting mission-worthiness is the leading point of emphasis and I selected a boat I considered best in class across it’s product evolution. Minimum viable complexity is a no-prisoners requirement in any machine I’ll own.. a top of mind consideration in anything I’m making/integrating... and the prime suspect on any system design I’m reviewing (“rescue consults”). People simply can’t help themselves on this point.

I’m reasonably educated and experienced in systems, design and electronics and have experienced significant exposure to why systems/machines fail (131 “rescue consults”) and why designers might go off the rails, how to approach design (think) to optimize for the system’s mission, and how to find the faults in system design prototypes. That perspective is how I ended up with Clock Work, and it is something maybe 20% of interested parties I’ve spoken with “get” from the start... The remaining 80% universally ends up nodding in agreement as we speak, though retention/bleed-off can be imperfect. I’m using a new method of generating leads and this new method will likely be (already is) expanding my need to have this conversation, so I decided what I hoped would be a simple cheat sheet for a certain potentially interested person who is not that “mechanical”... a person looking out at what’s available for a second-gen Nordic Tug 42 in the price range where you can actually find engine choice in the inventory, and what they might gain or lose stochastically from pushing their decision one way or the other. That is... it’s for a decider pre-choice.. not post (i.e. already has their boat). Posted here if anyone’s interested. Thanks.

Diesel Engine Complexity vs Reliability/Mission-Worthiness – Silicon vs Cast Iron

Take care,
G
 
Not sure about other TFers... I know some will read your post with interest.

I struggled.... not sure what you were getting at. Something like because you have a mechanical diesel you think that is a selling point?

I hope you get what you want... just skimmed over the post the first time and lost interest...read it a second time to actually try to understand it. Think I did.... everyone is different... but if all you are trying to do is convince people that a mechanical diesel is the way to go...you might try simplifying the post.

Many here are pretty smart... they either think mechanical diesels are the way to go or not really. Probably why I started wandering even in the first paragraph. Many buyers really don't get that detailed in powerplant selection.
 
Last edited:
I too struggled with the meaning of the post. But I certainly do like my 6CTA…
 
An interesting hypothetical to contemplate (it will never happen) is what would an engine designer at Cummins do, today, if there were no regulations on emissions? Completely mechanical engine? I doubt it, there are too many advantages of some electronic controls. Those electronic controls could be much simpler, since a large percentage of the complexity is in the emission control part of it.

If we look at gas engines, the best of them today is as reliable - actually much more reliable - than fully mechanical ones from the 50's and 60's. There is tremendous complexity in the electronics, but the electronics are also phenomenally reliable. Also, make diagnostics very easy, at least for the tech that has all the requires software - the restrictions on access to those is a business, not an engineering problem.
 
Bit of a head scratcher and I don't much understand the post. But I did notice that your mechanical 6CTA is controlled by electronic Glendenning controls. And that your bow and stern thrusters appear to be connected by an electronic interface. So if the intent is minimal complexity as stated in your post, that didn't appear to work, a choice was made to add complexity when it wasn't necessary. Just sayin'.
 
You might be underweighting the possibility that the people you discuss this with just have different priorities, so they nod and move on. Electronic diesels have some significant benefits that outweigh any theoretical reduction in reliability they may give us relative to mechanicals.

I own and operate both and prefer the cleaner running, less stinky, more efficient electronic Deere. We are only about 15,000miles into this one so too early to judge the reliability, but good so far.

I don’t mean to reopen the overworked debate about mechanical v electronic. I’m just suggesting that a prospective buyer may not share your engine preference even after being enlightened, because their priorities are different than yours.
 
Greetings,
Mr. G. Agreed although I think it is more redefining representation and plurality of application in an intersectional framework.
Perfect, RTF !
 
You might be underweighting the possibility that the people you discuss this with just have different priorities, so they nod and move on. Electronic diesels have some significant benefits that outweigh any theoretical reduction in reliability they may give us relative to mechanicals.

I don’t mean to reopen the overworked debate about mechanical v electronic. I’m just suggesting that a prospective buyer may not share your engine preference even after being enlightened, because their priorities are different than yours.

Agree.

FWIW, we had 6CTAs. Liked 'em. Now have electronically- controlled diesels. Like 'em (although I'd prefer an in-line 6 vs V8). I mostly prefer the advantages of the newer engines.

None of my preference needs Taylor Swift, Bono, Clooney (etc.) approval. :)

-Chris
 
Last edited:
I to got lost in the weeds of the original post.

However, I had a thought as a result of this thread, that I'd not had before. The Achilles heel of electronic engines is the electronics (brilliant, I know). Years ago, I flew ultralight aircraft. Failure of spark generation at the spark plug was enough of a risk that most of the aircraft that I flew, had redundant systems. Why not duplicate the injection system (or atleast the electronics) on a diesel. Have two independent systems that either fire together at half the rate, or alternate periodically. Obviously have an override in case one system fails.

In my own tier 2 John Deere diesel, having 2 independent ECMs to control the solenoid pulsing the injector pump would have been priceless. Maybe with tier 4 you would need two independent systems including the injectors, but independent redundancy would certainly reduce the risk of single engine boat failures, IMO.

Ted
 
I don’t think most Nordic Tug buyers care about your perception of the advantages of a mechanical diesel.

I’d wager most actually view the electronic engine as an advantage, since it’s more sociable (less smoke, easier starts, etc), should run better at very low loads it’s likely to see in a NT, and provides more diagnostic information to the operator.

To most buyers, the mechanical diesel just seems older and dirtier.

Do you have any data that shows electronic diesels are less reliable than mechanical diesels?
 
I chose the boat I have in part because it had a modern(ish) electronically controlled motor. Despite having had serious issues with those electronics I don't feel like it was a mistake.

Given that mechanical diesels are now well into mid-age it's hard for me to imagine a compelling case for choosing them over modern replacements from an overall reliability/service point of view. And the modern ones are quieter, better behaved and produce significantly less noxious exhaust.
 
Do you have any data that shows electronic diesels are less reliable than mechanical diesels?

My assumption is electronically controlled diesels are very reliable. I don't see many OTR trucks broke down with their engine bay open. But for a shade tree mechanic like myself, I believe I have a decent shot of receiving an old ailing diesel. Plus it sorta fits the genre of an old Willard - old technology for old technology. But there is much to recommend a modern diesel. They're quieter, lighter, more compact, smoother, cleaner, and more fuel efficient.

Peter
 
I wouldn't think so either.

Same as todays gas engines also computer controlled. If the engine shuts off, you call AAA - :)
 
Like Ted, I've thought lots about reducing the vulnerability of computer failure.

I'd lean more towards periodic preventative replacement of ECM and wiring harness. Say every ten years if you're super conservative. Keep the previous components for spare.

That's maybe 3k for parts on our small motors. Not an outrageous proposition.
 
Last edited:
In terms of functional specificity(thanks to K Rudd, ex PM now Australian Ambassador( and pontificating lecturer to US Govt and anyone else nearby), I doubt it really matters to buyers whether the engine is electronically controlled or not. But it might tip the scales for someone.
 
I see very little advantage to a mechanical diesel if the owner cannot work on diesels to begin with. The majority of boat buyers are limited in knowledge of propulsion systems.
In addition, most boat buyers are over concerned with the amount of fuel burn figuring that is the big costs. An electronic engine is going to be a big plus for most buyers.
Now if I were in Greenland, I would prefer the mechanical diesels but then I can work on diesels.
 
I see very little advantage to a mechanical diesel if the owner cannot work on diesels to begin with. The majority of boat buyers are limited in knowledge of propulsion systems.
In addition, most boat buyers are over concerned with the amount of fuel burn figuring that is the big costs. An electronic engine is going to be a big plus for most buyers.
Now if I were in Greenland, I would prefer the mechanical diesels but then I can work on diesels.
While it may have changed some, 10+ years ago a good diesel mechanic could work on a number of different manufacturers of diesel engines. Now with the proprietary software to diagnose engine problems, many times you are tied to an authorized dealer. Fine in a big boating area, but not if you're off the beaten path. When I had issues with my ECM, there wasn't a John Deere marine dealer on Lake Superior or Hurron. If it had been necessary, the same engine is used in John Deere agricultural and logging equipment, so I could have gone to one of those dealers.

Ted
 
Surprised no one has mentioned EMP (unless it was in the original post in which I too devolved into skimming). Over the years I have had a few clients looking specifically for steel yachts with mechanical engines. I almost started a trawler breakaway forum for conspiracists :)
 

Lightning is the most spectacular element of a thunderstorm. Lightning strikes release raw power in the form of electricity, light, and heat in a matter of milli- or even microseconds. While a direct lightning strike will cause significant damage to structures and electrical equipment, most damage results from electromagnetic pulses (EMPs). As such, most engineered structures require some form of EMP and surge protection.

Electromagnetic pulses from lightning strikes damage or destroy sensitive electronic equipment by generating over-voltage and power surges. Even though these surges are short-lived, they can drive tremendous amounts of energy through your facility’s electrical circuits, causing extensive damage to equipment and electrical systems.
 
Your discussion was way over my head, a challenging, slow and worthwhile read. Applying lessons learned and wisdom of others, I employed the basic application of simplicity in choosing my Camano, also putting keel and skeg protected prop on my list of requirements. The Volvo TAMD41 is a proven engine in recreational use, also in light commercial use, such as water taxis, so that was a plus. Adding to reliability, performance and maintenance reduction, I use Valve-Tect fuel and full synthetic 15W40 oil, which have combined to reduce smoke, and progressively clean up oil at the end of the last few seasons. Running a little higher RPM has eliminated carbon sludge in the exhaust, which was a problem at the end of my initial year as an owner. Shell's evaluations of T-6 full synthetic against their own blend and mineral oils are pretty compelling, all available on Shell's Rotella web site. Just to be safe I use the same additive for preventing bacteria/etc., in fuel that the Coast Guard uses. So, I get what you're saying about simplicity by design, but came about it more intuitively - keeping it simple, putting reliability in purchase, electronics (like 2 fixed, one hand held VHF) and maintenance decision. Nothing is fool proof, but we can prioritize reliability step by step. More to do on my boat to improve reliability, as always. Isn't that what winter is for?
 
Choices regarding engine complexity can be rather limited if one has to comply with pollution regulations. Engine choices, especially low HP engines, are limited to a few brands and models and the number of such engines is reduced even more when one has to comply with emission regulations.

One might want to lower engine complexity by having an mechanical engine but that might not be possible due to the various pollution regulations.
 
Greetings..

After 10 years, I’m in the process of selling my Nordic Tug 42 and doing that 100% myself for reasons that would not be interesting in a power forum. You have to, at a minimum message a product you’re intending to sell and for me that is easy... the clear value of a low-complexity/purely mechanically controlled diesel. My 6CT and the resulting mission-worthiness is the leading point of emphasis and I selected a boat I considered best in class across it’s product evolution. Minimum viable complexity is a no-prisoners requirement in any machine I’ll own.. a top of mind consideration in anything I’m making/integrating... and the prime suspect on any system design I’m reviewing (“rescue consults”). People simply can’t help themselves on this point.

I’m reasonably educated and experienced in systems, design and electronics and have experienced significant exposure to why systems/machines fail (131 “rescue consults”) and why designers might go off the rails, how to approach design (think) to optimize for the system’s mission, and how to find the faults in system design prototypes. That perspective is how I ended up with Clock Work, and it is something maybe 20% of interested parties I’ve spoken with “get” from the start... The remaining 80% universally ends up nodding in agreement as we speak, though retention/bleed-off can be imperfect. I’m using a new method of generating leads and this new method will likely be (already is) expanding my need to have this conversation, so I decided what I hoped would be a simple cheat sheet for a certain potentially interested person who is not that “mechanical”... a person looking out at what’s available for a second-gen Nordic Tug 42 in the price range where you can actually find engine choice in the inventory, and what they might gain or lose stochastically from pushing their decision one way or the other. That is... it’s for a decider pre-choice.. not post (i.e. already has their boat). Posted here if anyone’s interested. Thanks.

Diesel Engine Complexity vs Reliability/Mission-Worthiness – Silicon vs Cast Iron

Take care,
G
Interesting post. In the last 8 years I've owned a Perkins powered DeFever, QSB powered American Tug, and now buying a Lugger powered Nordhavn. Comments are welcome..... lol.
 
Complexity and reliability are not necessarily mutually exclusive, and complexity is in the eye of the beholder. I was overwhelmed by the complexity of my boat at first, but I have been coming around to appreciate how simple it is. "Only" 12 VDC. No propane. No solar. One diesel. One holding tank. Pretty simple in the scope of things.
 
Owning a first generation Nordic Tug (002), with a 6CTA, I appreciate simplicity. At the same time, I probably have one of the more complex electronics setups than most with a mixture of Garmin (new and old), Raymarine, and Coastal Explorer all tied together. The problem with complexity, if you don’t understand how it operates, you can’t troubleshoot the system. What’s missing in most complex electronic systems is a good discussion of the theory of operation. In other words, when I start my electronically controlled diesel what happens. There is a sequence of steps that the engine goes through to start, what are they. I guess if you go through the manufacturer’s school, you will learn those steps, but for us poor schmucks who buy a used boat that we intend to use in out of the way places, we need all the help we can get when it doesn’t start.

Even if we had the diagnostic software, without understanding how something operates, we are probably lost. Electronics has made engines more efficient, quieter, and more powerful. The diagnostics allowing the owner to understand what’s broken without a secret decoder ring hasn’t. If I was going to spend my time away from the crowds and a ready source of towing and repair, I would prefer my old mechanical diesel as I understand how it works, and carry enough parts to probably fix a few things.

Tom
 
The one thing I liked about my DD's is that they were totally mechanical, at least once started. Conversely, my QSM11s are reliant on ECMs that no mechanic can fix (at least so far as I understand, please correct me if I am wrong). I am told that if replacement of the ECMs (in a marine version QSM11) is necessary, the originals must be sent to the factory, where the replacement is programmed with the engine serial number and number of hours taken from the original ECM, which the factory keeps. It isn't even possible to buy backup ECMs (for safekeeping in a Faraday cage in order to be available for use immediately after an EMP event).
 
Last edited:
Back
Top Bottom