I see that mentions “storm oil”. Do you still carry oil bags or other apparatus for that use? I remember Knight’s Modern Seamanship ca 1949 talking about stabbing colza oil bags with a marlinspike to make a smooth.
Colza oil, marlin spikes; I’ve come over all moist.
Was this ‚storm oil’ ever more than ‚snake oil’ ?
I never understood how an oncoming braking wave could be ‘calmed’ with oil pushed by the storm just inches off the windward side of a ship. Leeward from the ship, there could be some flattening of the waves, with enormous quantities of thick oil… but would that be helpful to the ship?
Some 50 years ago, I read experiences with oil bags on sailing boats. They tried it just once.
The deck became inundated with oil; impossible to do anything useful on the slippery deck.
When the weather forecasts for the open oceans were nearly a lottery, a bottle of olive oil overboard, unscrewed or not, could have saved the ship… without knowing, if the ship could have survived without this bottle.
“Oil on troubled waters” has been an idiom since forever, I think.
Works great on a lake with ripples on it, and it doesn’t take large quantities – a tablespoonful to half an acre of water according to one of the clips below. You end up with a molecule-thick layer with the molecules all lined up so their watery tails are in the water, and their oily heads stick up and tend to move en masse with the wind instead of generating individual ripples.
I don’t know how this scales to the sea with breaking waves. Imperfectly, I imagine. IIRC Knights was advocating it with a bag fore and aft to make a smooth to leeward for launching boats.
Here’s an 1892 NYT article quoting twelve or so masters who wrote to the H.O. giving reports on oil effectiveness. All but one of them reported good results.
Benjamin Franklin famously investigated the calming properties of oil during his visits to England in the mid-18th century, demonstrating the effect on lakes such as Derwentwater. Communications between Franklin and William Brownrigg show that Franklin had first encountered the phenomenon aboard a ship in 1757 and investigated it several years later alongside Brownrigg and Sir John Pringle. This led to the discussion of the topic at the Royal Society on 2 June 1774.
An interesting theory about the dampening of breakers can be found here. Not all oils are suitable but especially fish oil seems to be very effective to smooth capillary wave action.
We have found data that allow modeling of these processes in a single episode recorded by the Hydrographic Office, the saving of the crew of a sinking vessel by the ship Martha Cobb under storm conditions in 1883 [Beehler, 1888]. Storm breakers were annulled in a limited area using oil for (our estimate) an hour, while breakers remained outside the area.
The oil has to have a a polar portion of its molecule, which pure hydrocarbon oils don’t but vegetable and fish oils do to varying degrees.
After the 1 h interval we model the slicked area to extend 3 to 6 km windward of the vessels, as follows. [emphasis mine]
Bloody hell! Because the vessels drift downwind faster than the slick.
These were sailing vessels with a lot of masts, rigging etc which caught a lot of the wind force hence a relatively large drift speed. The oil film will more or less ‘cling’ to the wave’s surface and will move slower. Well, that is my take on this phenomenon.
I believe that the storm oil carried in the lifeboats back in the day was to be dispersed from a container that was fitted into the sea anchor. The boat would be downwind from the sea anchor of course.
I’ve worked on vessels with containers of fish oil. I never thought it was required & thought we had them because over zealous bridge officers ordered them out of a abundance of caution. I’ve always been curious to know if pouring fish oil over the side would attract sharks & others predators under the water?
The USCG regulations also used to require that lifeboats be equipped with storm oil.
I suppose that they could be attracted by the ‘smell’ of the fish oil but that it would be probably useless as a snack.
Another fun fact: British lifeboat books specify “colza” oil for sea anchor work, as Hornblower mentioned. Colza oil is another name for what is called in the UK and Europe rapeseed oil. Rapeseed (pronounced rape-seed) is what is called in the USA “canola” oil. Another example of marketing to make an awful sounding food product sound better. That’s why you order king crab now instead of “spider crab”.
For oiling the fish so they don’t squeak and wake up the Old Man when he’s got his head down. :You know how he gets… :):
Note to Self: Be on something that floats & don’t dangle my fingers in the water if someone pours a bunch of chum oil overboard.
I was cadet on an old Laker, heavily modified over the years, and found reference to a storm oil dispensing system (long since removed) among the stacks of old drawings and manuals. I was out there in the summer and the storm oil seemed so removed from the endless glass calm hours cruising down the lake with the side ports open!
I’ve been told that if you use CBD oil, the sharks just want to rub up on you. If the CG asks, tell’em you didn’t inhale when you poured it over the side.