As we wait for someone to explain how the Dali lost power from its 55,000 hp (or 0!) German diesel engine, The Mysterious Case of Rudolf Diesel: Genius, Power, and Deception on the Eve of World War I (2023) may be worth a read. In addition to a biography of the man who created the efficient reliable (except sometimes) high-torque engines, the book has some interesting stuff about
- the rapid industrialization of Russia circa 1900 (I’ve read in other places that it was the world’s fastest growing economy prior to the revolution)
- the development of Standard Oil
- the utopian dreams of rich industrialists, including Diesel, circa 1900 (see also Andrew Carnegie!)
Who else would like this book? Greta Thunberg! Diesel predicted that we would completely trash the earth from burning fossil fuel (not an unreasonable prediction at the time given that cities were already horribly polluted from coal smoke), that we would run out of fossil fuel, and that solar energy would ultimately be our primary source of power. Diesel also loved the U.S., predicted that it would become and remain the world’s dominant industrial power, and was very impressed by our passenger train system(!). He thought that the U.S. was guaranteed to stay ahead of the Europeans in passenger rail because we weren’t constrained by old cities (i.e., California high-speed rail should be easy, quick, and cheap to construct!).
MAN was a leader in diesel technology 100+ years ago and remains a leader today, an interesting story in corporate continuity right through to making the Dali‘s engine.
Let’s have a look at the engine family… (for scale, check the staircases and handrails; source)
Mark Zuckerberg also chose German-made (MTU) diesel engines for his climate-saving yacht:
From Wikipedia: “Dali is propelled by a single low-speed two-stroke crosshead diesel engine coupled to a fixed-pitch propeller”. All news to me! I didn’t know that these large engines are two-stroke, and didn’t know about crosshead design, so this diagram was quite confusing initially.
I wonder what is “low-speed” in this context. Does it have continuous injections to move this huge piston slowly?
Greenspun would fill it with avgas.
Large two stroke marine diesels run at ~100 rpm (full speed). They have a single exhaust valve at the top of the cylinder. Fresh air, both as new combustion source and for scavenging (displace exhaust gases) is fed into the cylinder through a port at the bottom of the cylinder. There is no crankcase charging. Instead, modern two stroke marine diesels require positive intake air pressure for scavening, which is provided by blowers. At higher speed settings, that pressure is nowadays provided by a turbocharger, but for low speeds or at startup, it’s provided by an electric blower. Further, in modern engines, the exhaust valve is not mechanically actuated but through an electro-hydraulic system, so to allow for variable valve timing, Similar, the fuel injection and the fuel heating are all electric. Failure of a ship’s electric system will, therefore, stop the engine, just like it would in a modern car.
The diesels in small boats like the $300M Zuckerberg runabout are four stroke engines that run at 1000 rpm+, and typically drive generators for a diesel-electric propulsion.
Zukerberg’s runabout seems to be underpowered. Reported max speed is just 24 knots. Probably for pleasure cruising off Florida coast.
Stephan: Interesting. I had no idea that they were so dependent on electrics. I would have thought that once a big diesel engine started it would have enough of its own little generators to keep anything electric that it needed going (i.e., it wouldn’t depend on the overall electrical system of the entire ship). Kind of like an old Cessna 172 with the magnetos providing the spark and the generator and battery used for radios and other less-critical systems.
Maybe I was unclear. Large ships of course have a dedicated emergency electrical system for the engine, and for things like rudder, emergency navigation and radios. A blown main breaker on the general purpose bus will not stop a ship. The level of redundancy, however, is generally lower than what one finds in aviation, even when compared to a Cirrus piston.
What I wanted to express is that electrical issues can and do stop two stroke ship diesels for the reasons stated. That’s unlike, for example the common tractor or construction machinery diesel which is all mechanic. Those diesels, including the old two stroke Cummins etc., run even with the battery disconnected.
In a gasoline engine powered car, engine charges battery and battery keeps engine in operation. There is no extra power source in a vehicle, only original battery charge.
I would assume that diesel engines are built around the same idea, especially the kind thst goes on a boat.
Why hasn’t there been any news regarding an investigation into the electrical failure on the Dali? How tough can it be to figure out what went wrong?
There were such news: https://apnews.com/article/baltimore-bridge-collapse-investigation-85bd81d1dfefc6efc5bc9a2e22d6999a
Stephan: That just says that investigators are trying to figure out what went wrong and there isn’t any news about a finding!