Steam vs diesel

[Guest]

Interesting BBC Documentary on the history of the Diesel engine:

http://www.youtube.com/watch?v=wCA5pInfPpM

Long, and the only boats mentioned in any great detail are submarines and container ships but overall nice eye & mind candy for gearheads.

[Guest]

It seems that a comparison between the fuel consumption of the former steamers upgraded with diesel engine by Lower Lakes Towing before and after their repowerings would clearly demonstrate any fuel savings. This information, however, is likely unavailable for review.

I believe that during the 1960s US Steel took two nearly identical ships and repowered one with a Skinner Unaflow engine and the other with a diesel engine. I believe the results of this experienment resulted in a number of their older vessels being later repowered with diesel engines.

[Brian Ferguson]

Comparing apples to oranges. Dykstra had a larger beam than the Henry Ford II. Thus requiring more fuel to push it thru the water. No matter what you are moving, the faster you go, the more fuel you will burn.

Very marginally larger-

Dykstra 67' beam
Ford II 62' beam

2.5' per side which isn't much. I have the consumption hours on the William Clay Ford which is 8' wider than the Henry Ford II which I didn't use not because of the difference in beam but the totality of length, beam, and depth. Beam isn't a factor in fuel consumption between vessels of similar size as much as hull shape is, for example the Lee A. Tregurtha VS the James Oberstar, or a bulbed bow vs a traditional bow.

[Guest]

When CSL had there bulkers the bay boat 730s would burn almost double the Richelieu with the M/V also burning mostly heavy fuel with some pure diesel also, so quite a difference.

[Guest]

Having worked as an engineer on several steamers and motor vessels (including the Munson as both) I can honestly say that comparing the two plants are apples and oranges.

The diesel vessels have far more equipment, such as pumps, coolers, purifiers, etc. So they are more labor intensive to maintain, but they are far more economical to run when compared to the steamers. On the Munson for example the short runs it makes allows the ME to be shut down at the dock. So the only fuel used is for power generation.
Also, as others noted heavy fuel is going by the wayside on the lakes and the steamers have been grandfathered in. For now. That may change.

Another aspect that engineers face on the steamers is the age of the vessel and the lack of parts. The AAAs were all built in the early 50s and many parts for the the plant and supporting equipment are not necessarily readily available and have to be specially made.

[Guest]

Bunker C is cheaper than diesel. Ok a lot cheaper.

But it is no longer legal to use Bunker C, and in the few parts of the world where it is still legal it is hard to find.

What makes you say it is no longer legal to use Bunker C? HFO and IFO (Bunker C) is still widely available and utilized. Granted a vessel must be equipped with an Exhaust Gas Cleaning system or in some limited cases be grandfathered like the Sykes.

[djwmusk65]

When the Lee A. Tregurtha was converted to diesel,it was my understanding that her fuel cost was reduced by half. Along with the fuel is also the savings with fewer engine room crew. There is no need for boiler tenders,firemen(if they still had them) plus if you install an engine monitoring system, it can be certified for unmanned operation and that gives you further savings. This is how 300,000 dtw tankers or bulk carriers with a crew of 10 or 12, or the Wagonborg boats with a crew of 8.

[Guest]

Both plants require maintenance to be reliable. They both have their pluses and minuses. The big difference is that steam plants burn a lot of fuel. Most of the time, fuel is a big portion of operating costs, often exceeding personnel costs. Steam is romantic, but not very efficient.

Bunker C is cheaper than diesel. Ok a lot cheaper.

Bunker C maybe cheaper but steamers use A LOT more of it than even a heavy oil fueled diesel.

For example in the Ford years two similar sized ships, their power plant, and fuel consumption

John Dykstra 644' 5000hp De Laval turbine 350 gallons/hour

Henry Ford II 612 feet 3000hp Sun-Doxford Diesel 160 gallons/hr

Granted the Dykstra is marginally bigger and has more power but that "state of the art" for the time steam set up used more than double the fuel per hour. The diesel also occupied less space than the boilers and turbines. 13mph was the industry standard for speed until the Sykes came out and when the saltwater conversions came out fuel mileage was thrown out the window. On all the ships I worked on there was a rubric of such a speed, at such a draft, burns this much fuel, which figures the bottom line at X It was all math. When I was on the Roger Blough it never moved as fast as it could.

Comparing apples to oranges. Dykstra had a larger beam than the Henry Ford II. Thus requiring more fuel to push it thru the water. No matter what you are moving, the faster you go, the more fuel you will burn.

[JFB]

Bunker C is cheaper than diesel. Ok a lot cheaper.

But it is no longer legal to use Bunker C, and in the few parts of the world where it is still legal it is hard to find.

[GuestfromEU]

Just to put things into perspective:

Assuming Bunker C presently costs somewhere around $300 per metric ton on the lakes
(current rates for other places here http://shipandbunker.com/price)

And Bunker C Distillate No 6 weighs about 8.25 pounds per gallon

Then one metric ton would contain around 267 gallons

Which would make it about $1.12 per gallon + taxes and bunkering fees

Your calculations are correct. Two quick notes to add:

1) Ships are generally exempt from sales tax on purchases, including fuel. They load red-dyed diesel oil in the USA, same as off-road equipment. Often a delivery, or barge fee, will be added, often $10k-50k flat fee depending on the port and quantity of bunkers delivered.

2) The current bunker pricing noted on the website for Houston and New York is very different than pricing in the Great Lakes. Shipping companies often use many tools to their advantage - buying on a fixed rate, discounts for X amount of purchase by volume in a given timespan, and working with brokers to secure the best price.

Sarnia is currently around $300/MT of HSHFO 380 (suitable for ships with scrubbers), and $620/MT for ULSMGO (0.1% sulphur). Compare this to Houston (often the cheapest bunker port in the world), LSHFO 380 and ULSMGO are tracking at a $20-40 spread, e.g. $230/MT for LSHFO, $260/MT for ULSMGO, $168/MT for HSHFO.

Bunker "C" is terminology no longer used within the bunker industry. That designation dates from a time when fuel blending and categorisation was far less strict than now. It was known as the "leftovers from the refinery", and often could be. Many engineers on motor ships will recall taking bunkers full of cat fines, cleaning filters as fast as they could for days. Those times are mostly gone now, but not unheard of, thanks to independent lab testing and shipowners not afraid to file suit against bunker supplies who deliver off-spec fuel. Steamships often only had a coarse filter for removing large particles, as nothing more was needed. Fuel quality and energy contained per volume measurement were not tracked so closely in the heyday of steamships. Now, real-time monitoring tracks the exact fuel consumption on new ships to a very precise value.

[Colin]

Bunker C is cheaper than diesel. Ok a lot cheaper.

What are the current prices of the two? I could not figure it out.

[Brian Ferguson]

Both plants require maintenance to be reliable. They both have their pluses and minuses. The big difference is that steam plants burn a lot of fuel. Most of the time, fuel is a big portion of operating costs, often exceeding personnel costs. Steam is romantic, but not very efficient.

Bunker C is cheaper than diesel. Ok a lot cheaper.

Bunker C maybe cheaper but steamers use A LOT more of it than even a heavy oil fueled diesel.

For example in the Ford years two similar sized ships, their power plant, and fuel consumption

John Dykstra 644' 5000hp De Laval turbine 350 gallons/hour

Henry Ford II 612 feet 3000hp Sun-Doxford Diesel 160 gallons/hr

Granted the Dykstra is marginally bigger and has more power but that "state of the art" for the time steam set up used more than double the fuel per hour. The diesel also occupied less space than the boilers and turbines. 13mph was the industry standard for speed until the Sykes came out and when the saltwater conversions came out fuel mileage was thrown out the window. On all the ships I worked on there was a rubric of such a speed, at such a draft, burns this much fuel, which figures the bottom line at X It was all math. When I was on the Roger Blough it never moved as fast as it could.

[Guest]

Just to put things into perspective:

Assuming Bunker C presently costs somewhere around $300 per metric ton on the lakes
(current rates for other places here http://shipandbunker.com/price)

And Bunker C Distillate No 6 weighs about 8.25 pounds per gallon

Then one metric ton would contain around 267 gallons

Which would make it about $1.12 per gallon + taxes and bunkering fees

[navarch]

Disclaimer, I do not have experience operating ships hands-on, but I am a naval architect/marine engineer that understands the working principle and am familiar with fleets on the Great Lakes, including many of the steam-to-diesel repowers that have happened.

While steam turbines themselves are quite reliable (just single rotating component) and can last many decades, boilers become maintenance intensive, and anyone involved in fleet maintenance can tell you that re-tubing a boiler is VERY expensive. Modern diesel engines have more moving parts, but many of these are designed for maintenance (removable cylinder liners, modern computer diagnostics, etc.).

Economically, while Bunker C or HFO is indeed much cheaper than No. 2 Diesel, many of the steam-to-diesel re-powers can still burn HFO, and on top of that are MUCH more fuel efficient. Diesel engines can also run shaft generators from their gearboxes, saving fuel vs. running an independent generator. Modern diesel engines also offer a variety of systems that can reduce pollution in a way that would not work as well on a steam turbine (EGR, SCR, scrubbers, etc.).

From a safety standpoint, many diesel powerplants use two engines for redundancy and do not have many high-pressure boilers or steam lines that can leak/explode. Diesel engines can also maneuver more safely due to controllable pitch propellers (can reverse much quicker) and direct pilot house control of the pilot-house system.

I get the romance of steam engines, and it's hard to replace the sound of a classic steam whistle. But there is no denying the benefits of a modern diesel engines.

[Guest]

Both plants require maintenance to be reliable. They both have their pluses and minuses. The big difference is that steam plants burn a lot of fuel. Most of the time, fuel is a big portion of operating costs, often exceeding personnel costs. Steam is romantic, but not very efficient.

Bunker C is cheaper than diesel. Ok a lot cheaper.

[Guest]

It’s like anything concerning noise in life. You adapt n get used to it. Always noise on a ship no matter the type of engine. On conventional style Lakers it is quiet up forward but not so much back aft.

[Guest]

Question for sailors out there when you used to hear steamships passing down a lock etc it was practically silent, then you'd hear a diesel some very loud like the lakers with 4 fairbanks so question is did you notice the noise of the engines when sleeping or eating?

[guest346]

Both plants require maintenance to be reliable. They both have their pluses and minuses. The big difference is that steam plants burn a lot of fuel. Most of the time, fuel is a big portion of operating costs, often exceeding personnel costs. Steam is romantic, but not very efficient.

[Guest]

The weak link in a steam plant are the boilers. The tubes would wear, pumps would fail, but as long as the turbine had steam it would keep running. I also enjoyed the triple expansion steam engines. My Dad peeled me away from the rail on the Boblo boat when we reached the island.

[Guest]

Very true. However, steamers are still more reliable than diesels and quieter.

Not that I disagree, but on what do you base the claim that steamers are more reliable?

My father-in-law was a retired GE turbine specialist. He installed and maintained GE turbines all across the mid west. He even balanced the turbine on the Munson one year during their five year inspection. The Munson has a GE turbine where the AAA’s have Westinghouse.