# Why do ocean-going vessels burn oil instead of diesel? **URL:** \ **Category:** Factual Questions\ **Created:** [May 15, 2013, 1:55am UTC](https://boards.straightdope.com/t/why-do-ocean-going-vessels-burn-oil-instead-of-diesel/658367 "2013-05-15T01:55:01Z")\ **Posts on this page:** 9\ **Page:** 2
**Author:** ![Sailboat](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/sailboat/32/461_2.png) [@Sailboat](https://boards.straightdope.com/u/Sailboat)\ **Post date:** [May 16, 2013, 5:30pm UTC](https://boards.straightdope.com/t/why-do-ocean-going-vessels-burn-oil-instead-of-diesel/658367/21 "2013-05-16T17:30:23Z")
> [@Son\_of\_a\_Rich](#): > > Seems like the most environmentally friendly way to propel ships would be to somehow use wind power. I wonder if anyone has ever tried that. Historian John Keegan has written that few things built by Man have been so perfectly suited to their purpose as the sailing vessel. For several hundred years, the square-rigged men of war were able to go anywhere the oceans reached, on voyages lasting up to years at a time, keeping to sea except when needing to replenish food or water, using no fuel, and they could be heeled over on any beach and repaired (usually using local materials). When coal-powered ships came along, we were freed from most\* concerns about wind direction, but paid a heavy price – the ships suffered vastly shorter radius of operation, and coaling was a dirty, lengthy process of backbreaking labor, frequently repeated. Obtaining adequate bases for coaling provided the impetus for a lot of competition and colonization and perhaps influenced several wars. Metal ships could generally only be repaired in dock facilities. \*Wind direction remained a significant factor in many coal-era battles because dense smoke from a fleet could blind gunners and hide ships and signal flags. ---
**Author:** ![Snnipe\_70E](https://avatars.discourse-cdn.com/v4/letter/s/b5a626/32.png) [@Snnipe\_70E](https://boards.straightdope.com/u/Snnipe_70E)\ **Post date:** [May 16, 2013, 6:32pm UTC](https://boards.straightdope.com/t/why-do-ocean-going-vessels-burn-oil-instead-of-diesel/658367/22 "2013-05-16T18:32:04Z")
> [@bump](#): > > It’s doubtful that the Navy would re-work one of their carriers to use a fuel significantly different than what the rest of the conventionally fueled ships used in that time frame. > > What’s more likely is that the Navy as a whole, moved from some heavy grade of bunker oil- like #5, to something much lighter like bunker A, or even something that both steam turbine ships and gas turbine ships can both run. > > During the 1960s and 1970s, there was a fairly significant change among the frigates, destroyers and cruisers of the Navy to be gas-turbine powered instead of using the old steam turbines. So it makes sense that a carrier battle group would want to use the same fuel for everything. The Navy used what was called NavySpecial. That was bunker “C” cut with enough deisel that it could be pumped with out heating and only heated to around 130 degrees F to burn in the boilers. Problem with this oil was it was still a residual fuel and contained dirt. Sometime in the late 60’s or 70’s the Navy changed over to #5 which is a distilled fuel and therefore does not have dirt in it. Boilers, gas turbines, and diesel ships can burn both Bunker “C” or 35 fuel oil. ---
**Author:** ![Learjeff](https://avatars.discourse-cdn.com/v4/letter/l/94ad74/32.png) [@Learjeff](https://boards.straightdope.com/u/Learjeff)\ **Post date:** [May 16, 2013, 7:21pm UTC](https://boards.straightdope.com/t/why-do-ocean-going-vessels-burn-oil-instead-of-diesel/658367/23 "2013-05-16T19:21:20Z")
> [@Snnipe\_70E](#): > > When bunker “C” is room temperature is is not quite solid. But it is too thick to be pumped. In fact I have seen water float on bunker “C”. It must have been winter, then, because he talked about walking around on top of the fuel, taking measurements. > [@Sailboat](#): > > … coaling was a dirty, lengthy process of backbreaking labor, frequently repeated. Of course, working on a sailing ship was constant toil, as well. Cf., [Two Years Before the Mast](http://en.wikipedia.org/wiki/Two_Years_Before_the_Mast) by Richard Henry Dana (non-fiction). A well-spent $1 for my ebook! Highly recommended to anyone who is interested in tall-ship seamanship of the early-to-mid 1800’s. Still, I think I’d rather crawl the ratlines than shovel coal. ---
**Author:** ![gnoitall](https://avatars.discourse-cdn.com/v4/letter/g/bb73d2/32.png) [@gnoitall](https://boards.straightdope.com/u/gnoitall)\ **Post date:** [May 16, 2013, 7:30pm UTC](https://boards.straightdope.com/t/why-do-ocean-going-vessels-burn-oil-instead-of-diesel/658367/24 "2013-05-16T19:30:23Z")
> [@Sailboat](#): > > Historian John Keegan has written that few things built by Man have been so perfectly suited to their purpose as the sailing vessel. For several hundred years, the square-rigged men of war were able to go anywhere the oceans reached, on voyages lasting up to years at a time, keeping to sea except when needing to replenish food or water, using no fuel, and they could be heeled over on any beach and repaired (usually using local materials). > > When coal-powered ships came along, we were freed from most\* concerns about wind direction, but paid a heavy price – the ships suffered vastly shorter radius of operation, and coaling was a dirty, lengthy process of backbreaking labor, frequently repeated. Obtaining adequate bases for coaling provided the impetus for a lot of competition and colonization and perhaps influenced several wars. Metal ships could generally only be repaired in dock facilities. > > \*Wind direction remained a significant factor in many coal-era battles because dense smoke from a fleet could blind gunners and hide ships and signal flags. And sea empires became land empires, because the worldwide military naval power of an empire became logistically more dependent on reliable shore assets with strong and secure resource-gathering hinterlands. Horatio Hornblower, Master and Commander of His Majesty’s (more or less) independent frigate, went the way of fixed regional fleets tied to permanent overseas bases. The shape of modern sea power. Although colonization had been driving inland for centuries (cuz that’s where the gold, and the farmable land, etc.) were. I guess it’s not so much that the shorter ranges of non-wind-powered ships specifically inspired inland land empires, but rather greatly increased the perceived need for them. Interesting insight. I always liked Sir John’s work. ---
**Author:** ![phreesh](https://avatars.discourse-cdn.com/v4/letter/p/9fc29f/32.png) [@phreesh](https://boards.straightdope.com/u/phreesh)\ **Post date:** [May 16, 2013, 8:14pm UTC](https://boards.straightdope.com/t/why-do-ocean-going-vessels-burn-oil-instead-of-diesel/658367/25 "2013-05-16T20:14:41Z")
> [@Son\_of\_a\_Rich](#): > > Seems like the most environmentally friendly way to propel ships would be to somehow use wind power. I wonder if anyone has ever tried that. Installing wind turbines on a ship would be highly complicated and I can’t imagine they’d be very efficient. I think we’re probably at least decades away from a ship that utilizes the wind to ever be feasible. 🙂 ---
**Author:** ![Sailboat](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/sailboat/32/461_2.png) [@Sailboat](https://boards.straightdope.com/u/Sailboat)\ **Post date:** [May 16, 2013, 11:28pm UTC](https://boards.straightdope.com/t/why-do-ocean-going-vessels-burn-oil-instead-of-diesel/658367/26 "2013-05-16T23:28:48Z")
> [@phreesh](#): > > Installing wind turbines on a ship would be highly complicated and I can’t imagine they’d be very efficient. I think we’re probably at least decades away from a ship that utilizes the wind to ever be feasible. 🙂 I know it’s a joke, but…[Rotor Ships](http://en.wikipedia.org/wiki/Rotor_ship). ---
**Author:** ![Enola\_Straight](https://avatars.discourse-cdn.com/v4/letter/e/dec6dc/32.png) [@Enola\_Straight](https://boards.straightdope.com/u/Enola_Straight)\ **Post date:** [May 17, 2013, 3:17am UTC](https://boards.straightdope.com/t/why-do-ocean-going-vessels-burn-oil-instead-of-diesel/658367/27 "2013-05-17T03:17:18Z")
Those running used deep fryer grease in their diesel vehicles are using the same setup…using a heat exchanger (antifreeze) to heat the viscous grease to the point where it is thin enough to be atomized by injectors. In any case, a superior heat exchanger source has been tapped…the oil return line from the turbocharger. ---
**Author:** ![phreesh](https://avatars.discourse-cdn.com/v4/letter/p/9fc29f/32.png) [@phreesh](https://boards.straightdope.com/u/phreesh)\ **Post date:** [May 17, 2013, 3:12pm UTC](https://boards.straightdope.com/t/why-do-ocean-going-vessels-burn-oil-instead-of-diesel/658367/28 "2013-05-17T15:12:34Z")
> [@Sailboat](#): > > I know it’s a joke, but…[Rotor Ships](http://en.wikipedia.org/wiki/Rotor_ship). My company used Enercon for its wind power project and their rotor ship mentioned in your link brought the turbines over from Germany. There were plenty of jokes about wind-powered ships going around the office. ---
**Author:** ![Learjeff](https://avatars.discourse-cdn.com/v4/letter/l/94ad74/32.png) [@Learjeff](https://boards.straightdope.com/u/Learjeff)\ **Post date:** [May 17, 2013, 3:45pm UTC](https://boards.straightdope.com/t/why-do-ocean-going-vessels-burn-oil-instead-of-diesel/658367/29 "2013-05-17T15:45:27Z")
> [@Sailboat](#): > > I know it’s a joke, but…[Rotor Ships](http://en.wikipedia.org/wiki/Rotor_ship). I have an essay by Einstein where he explains the Flettner ship, and points out that the motor to turn the cylinder can be as small as feasible; the amount of power delivered by the cylindrical “sail” is independent of the power of the motor. The motor only needs to turn the rotor, and propulsion doesn’t “fight” against the turning of the rotor. Pretty cool, really. Plus they point higher than conventional sails, according to the wiki page. [Previous page](https://boards.straightdope.com/t/why-do-ocean-going-vessels-burn-oil-instead-of-diesel/658367.md?page=1)