The adoption of tanks will be facilitated by pump development. In the old timeline, Truscott's pump was officially adopted in 1812, and it could be used to pump water from the water tanks directly to the cooking coppers via leather tubes (Macdonald 85).
The iron tanks, typically of rectangular or square plan, could be close-fitted and overall occupied half the space of an equal capacity of casks. However, a danger in close fitting is that water can leak if the tank is overfilled and, draining down through the cracks in-between the tanks, cause rusting of the tanks and rotting of the wood underneath (Stevens 864). In 1871, Admiralty tanks ranged from 100 to 600 gallons (17-101 cubic feet) capacity and weighed 364-1190 pounds empty (Stevens 31). Note that large tanks are more weight-efficient than small ones. The actual water weighs 8.34 pounds per US liquid gallon (3.785 L, almost the same as the wine gallon of 3.79 L).
While it is certainly possible to fill or empty a large iron tank (too large or heavy to move) a bucket at a time, preferably water can be pumped in or out with a hose. I will talk about pumping in a later part.
It should be noted that iron water tanks should be placed well away from the ship's compass, if possible, or the deviation caused by the tank noted for future reference. Commander Walker reported that in 1818, he set a WNW compass course, but found that the ship, equipped with new iron water tanks, actually bore NNE, and, after sailing 21 miles, was at least eight leagues further south than it should have been (Walker 84).
Reviewing a draft of this manuscript, Jack Carroll suggested that it may be advantageous to apply a thin copper coating to the inside of an iron water tank in order to inhibit rust, and that in the new time line this can be practically achieved by electrodeposition of a very thin metallic coating on plates, and the plates then shaped and riveted together.
While copper by definition cannot rust (i.e., form iron oxide), it is corroded (tarnished) by fresh water (although being lower than iron in the galvanic series, it is corroded more slowly). The corrosion rate is dependent on pH, dissolved oxygen and carbon dioxide, and hardness (Rossum).
Another advantage of copper is inhibition of microorganisms (oligodynamic effect, discovered 1893). However, if the water were used to reconstitute a vitamin C-rich juice concentrate, the copper ions would catalyze oxidation of the vitamin C (see below).
Watering a Ship. Transferring water to a ship had its own difficulties. In this period, water is likely to be in casks, either carried by boats or rafted over. Rafting was necessary on a coast with a surf, as a heavily laden boat could otherwise be swamped. The casks could be towed broadside on, in single file, or end on, in pairs.
Later, canvas or leather bags were supplied to boats, and they would be filled by hoses from a shore pump. Typically, the bag had two halves that saddled the boat (Henderson 183).
Seawater. If you run out of the stored beverage, you're in trouble, because drinking seawater in significant quantities leads ultimately to dehydration. Seawater is 3% salt, and the kidney can't make urine from water saltier than 2%, so it take the water it needs from the tissues (docastaway.com). This is obviously self-defeating. As Coleridge's Ancient Mariner put it, “Water, water, every where, Nor any drop to drink.”
Shore collection. If a ship was near shore, it might send a landing party to look for fresh water, hoping to find a spring or stream. There was of course the danger of encountering hostile inhabitants or merely of unwittingly collecting water from a contaminated source.
Rainwater Harvesting. One method of catching rain was simply to plug the scuppers and collect the water from the main deck. Of course, the water is likely to pick up all sorts of nasty stuff that was on the deck. In a similar way, you could catch it from the roof of the superstructure, assuming you could improvise a wall so it wouldn't just run off the roof. You could set out buckets, or spread canvas horizontally, attaching it to the mast and rigging, and empty the harvested rain into a cask.
There were two problems. First, whether it would rain or not was unpredictable. Second, the collection methods were likely to lose water if the ship were rocking (and rain tends to be associated with rough water). Finally, how much rain could be collected would depend on how much surface area could be presented to the skies above, and on a ship, space was at a premium.
Melted Ice. Ships traveling in high latitudes in winter may encounter icebergs, sea ice and snow. New sea ice (formed by freezing of seawater) is actually very salty, but as ice ages the brine is expelled by various mechanisms. Icebergs are made of freshwater ice.
Melting ice or snow requires much less heat than boiling seawater. Icebergs thus provide opportunity as well as risk: on January 9, 1773, the second lieutenant of the Adventure, James Burney wrote, "being very fine Weather we brought too by an Island of Ice & hoisted our Boats out to pick up the loose pieces to water the Ship—we got 6 Boat Loads which when melted in the Coppers gave us 7 Tons of Excellent fresh water" (captaincooksociety.com). This expedient was apparently resorted to at least as early as 1671 (Goethe). I suspect this is a reference to a whaling expedition to Spitzbergen, memorialized by Friderich Martens in 1675.
Fish. While you do not want to eat high-protein food when you are thirsty and short of water, you can drink the aqueous fluid from the eyes and spine bones, which is almost free of salt (Soule).
Desalinated Seawater. The separation of salt from water goes back to ancient times; but generally it was the salt, not the water, that was sought. Salt production of course was simpler. the sea would rush over a dam at high tide; some of the seawater would remain behind when the tide receded; and the confined seawater would be heated and evaporated by the sun, leaving the salt behind.
A thirsty mariner, however, does not want the water vapor to escape, but rather to trap it and allow it to cool and condense.
Desalination with a “Fire Still”. There was both classical and ecclesiastical authority for desalination by distillation. Aristotle (Meteorology lib. ii. ch. ii.) proclaimed, "Sea-water can be rendered potable by distillation: wine and other liquids can be submitted to the same process. After they have been converted into humid vapors they return to liquids." In his fourth homily, Saint Basil said that having been shipwrecked on an island without drinking water, he and his companions heated saltwater in an iron basin and condensed the vapor on sponges, squeezing out the fresh water (Stevenson 2:569 n2).
These statements were put to the test by mariners before the RoF. Sir Richard Hawkins wrote that in his South Sea voyage of 1593, "with an invention I had in my ship, I easily drew out of the water of the sea, sufficient quantities of fresh water to sustain my people with little expense of fuel; for with four billets I distilled a hogshead of water … The water so distilled, we found to be wholesome and nourishing" (Hawkins 82). In 1606, a Spanish captain, finding that he had been shorted water barrels, likewise made "sweet water” by distillation using "a copper instrument he had with him" — i.e., not an improvised device (Queiros 196).
The Dutch, notably Jan Huygen van Linschoten (d. 1611), Aegidius Snoeck (d. 1637), and Cornelius Drebbel (d. 1633), promoted shipboard distillation technology (Delyannis 6). Nonetheless, it appears that at least VOC crews were prejudiced against it for some reason (Beekman 23), and Snoeck's 1620 device was expensive (Torck 214).
There was also, unfortunately, a strange belief that distilled water was not pure, but rather also included "a bituminous substance, and a spirit of sea salt" (Lind 332). This in turn led those experimenting with distillation to add various neutralizing substances that probably did more harm than good. For example, in the time of Charles II it was proposed to add lime (Columb 12) and in 1753 Appleby essayed lapis infernalis and calcined bones (Lind 334). About the same time Alston promoted limestone and Hales, powdered chalk. Soon thereafter, Doctor James Lind conducted a controlled experiment, to compare the various proposed additives, and was surprised to discover that the control (distilled seawater with nothing added) was equal in quality to distilled rainwater. He published his findings in 1761,
and proposed that for distilling water, the ship's copper pots, used for boiling victuals, be fitted with "still-head covers," and a pipe used to carry the steam from the pot to a cask of cold water (336-344). A trial was conducted in 1768, on the Dolphin; "56 gallons of sea water were put into a still, and 42 gallons of fresh water drawn off in the space of five hours thirteen minutes, with the expense of nine pounds of wood, and of sixty-nine pounds weight of coals; this was upward of a quart of water for each man on board" (345).
Lind even described a method of improvising the still using the pot, a tea kettle (or a wooden hand pump), a musket barrel, and a cask (Ibid). In the Dorsetshire, this kludge converted 22 quarts of seawater to 19 quarts of fresh water in four hours, expending ten pounds of wood (Clarke 130).
In the eighteenth century British navy, the ship's kettle was divided in half by a partition, and peas and oatmeal were cooked on only one side, but with water kept on the other. Doctor Irving showed that the spare half of the kettle could be filled with seawater and distilled by a method similar to Lind's, while the peas or oatmeal were boiling, without any additional fuel (Falconer 428).
The 74-gun HMS Aboukir (1807) was one of at least thirty ships equipped in 1809 with the "Lamb Patent Fire-Hearth," which had three boilers. With saltwater in one of them, it would produce eight gallons of freshwater an hour, without extra fuel being consumed. And of course you could use all three boilers at once in an emergency to produce twenty -four gallons per hour (Naval Economy, 1811, pp. 16-22).
It's hard to be sure, but it appears that the nineteenth-century sailing ships carrying distillation apparatus were primarily exploration vessels (Cook's Resolution) and large warships and East Indiamen. The development of steamships gave additional impetus to distillation technology. If seawater were used in the boiler, there was a buildup of brine and scale. Hence, they used freshwater. With efficient condensers, the initial charge of freshwater could be mostly recycled, but the system needed to take in additional feedwater to make up for losses. However, note that for this water to also be useful as drinking water, the system had to be designed to avoid contaminating it with lubricants. The fuel consumption necessitated by the evaporator could be minimized if the heat source was the exhaust from the main engines, but unfortunately it varied in heat value depending on the operating condition of the engines (USN).
It's evident that at least the basic Lind distiller doesn't require anything beyond the pre-RoF technological infrastructure and thus could be adopted as soon as someone thinks to do so.
It has been suggested that the thermal efficiency of the still could be improved by a cross-flow heat exchanger to exchange heat between the distillate and the feedwater. Actually cross-flow heat exchangers (hot fluid flow perpendicular to cold fluid flow) are not as efficient as counter flow models (hot and cold fluid flows are parallel but in opposite directions) but more efficient than parallel flow (same direction).
If the seawater were taken up manually, by the bucket, it could be poured into the intake for a concentric condenser jacket, and then passed through the jacket and ultimately into the boiler of the still. If the feedwater moved by gravity flow, then this would in effect be a parallel flow heat exchanger because the condenser would be arranged so the condensate would flow by gravity away from the boiler. However, one could pump the feedwater upward to make it a counterflow device. Or instead of using a concentric jacket, the feedwater could pass by gravity through a tube that spiraled around the vapor tube, resulting in cross-flow heat transfer.
All of these improvements in heat efficiency come with the disadvantages of increased space requirements and cost and are unlikely to be adopted unless fuel costs are high.
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There is a possibility that early seventeenth-century Japanese mariners, like Hawkins, resorted to distillation of seawater in emergencies. That they did so in the nineteenth century is well established.
When the Japanese merchant ship Tokuju-Maru was left adrift in 1813 as a result of a storm, they had plenty of soybeans but little drinking water. So Captain Jukichi rigged a makeshift still: "seawater is boiled in a big kettle. A pipe is poked through a hole in the bottom of a big pot which is then placed on top of the kettle. As the steam passes through the pipe and cools, it forms into drops of water, which are then collected in the pot for drinking water. By using this ranbiki they were able to make about 7 or 8 shi [about 14 liters] of water per day … ." (Torck 221; Plummer 80).
A study of nineteenth-century Japanese castaways identified seven incidents, Jukichi's included, in which seawater was desalinated by distillation. Five of them claimed to have either designed the device themselves or to have been inspired by a dream (Jukichi included). But the frequency of adoption of this expedient suggests that "it was common knowledge among both maritime communities and alcohol distilleries" (Wood 110).
Jukichi's device was a makeshift ranbiki; the purpose-built one, used by Japanese apothecaries, was more elaborate. It was made of ceramic or copper, and had three chambers: one holding a liquid, to be heated by a charcoal fire; a top chamber to receive the evaporate; and a middle chamber that could be filled with herbs from which the steam could extract herbal oils. The evaporate condensed in the top chamber and the condensate descended through a side pipe, dripping into a receptacle. The top chamber was equipped with an annular cooling tube (Michel).
Some think the Portuguese introduced the ranbiki (the name is thought to come from "alembic") to Japanese medical practice If that is correct, then it occurred before 1639, when the Portuguese were evicted. On the other hand, it is possible that it was part of the "Dutch Learning," and if so might have come later; a distillery for essential oil extraction was established by the Dutch on Deshima in 1671 (Michel).
It may even have come from the Ryukyu Islands rather than from the Europeans. There, on Okinawa, they drank awamori, made by distilling alcohol from fermented rice. It is sometimes called "island sake;" but sake is not distilled—the Japanese equivalent is shochu. Awamori was sent as tribute to China at least as early as the fifteenth century (Wikipedia), and so the Okinawans were practicing distillation back then. And distillation was learned from the Siamese.
In view of this history, I assumed that some Japanese mariners in the seventeenth century have knowledge of distillation and might think of it in a water crisis. In 1636: Seas of Fortune, the Japanese expedition to Vancouver Island encounters a Japanese castaway who recounts a tragedy similar to Captain Jukichi's, but his is set in 1624. And he, like Jukichi, rigs a distillation apparatus.
My only technical criticism of Jukichi's device is that since the connecting tube is vertical, the condensate might run back down into the boiler. Perhaps it would be better for the boiler and the condenser to be side-by-side, with an upside-down U-shaped tube connecting them, thus mimicking a retort.
Desalination with a Solar Still. One of the disadvantages of the "fire still" is its demand for fuel. If the water is heated by the sun, no fuel is needed. Solar distillation of water is described by Della Porta's Magiae Naturalis (1589) so it's not an alien concept for the down-timers.
The up-timers are certainly aware of the possibility of constructing a "solar still," in which heat is supplied by the sun. Wilderness survival books will almost certainly mention the basic "pit" type in which one digs a cone-shaped hole in the ground, buries a collection cup at the center, and suspends a plastic sheet over the cup.
Probably the simplest still design suitable for shipboard is a single slope box still. The box has a blackened sides and bottom (to better absorb solar radiation) and the seawater is placed inside. The roof is made of glass and inclined; the lower end overhangs a collection trough outside the box. Water vapor condenses on the relatively cold glass and runs down the inner surface, and out through a gap between the downslope side wall and the glass, and falls into the trough. The still is pointed toward the sun (so sunlight strikes the glass as close to perpendicularly as possible). The amount of fresh water collected is of c
ourse dependent on the amount of solar energy striking and absorbed by the seawater (which depends on latitude, time of year, time of day, cloud cover, angle of incidence, and the projected surface area) relative to the latent heat of vaporization of water. The efficiency of this simple system can reach 60% (Suresh).
The transparent glass has several important functions: it lets visible light through, it blocks the escape of heat radiation and water vapor, and it provides a track for the condensate.
For shipboard use, the collection trough must be high-walled enough so that the water doesn't spill out when the ship rocks. A further concern is that a wave might crash down on deck and bring seawater into the trough. Hence, it would be better if the trough were contained by making it a partitioned-off portion of the box, thus protecting it from wave action (and also evaporation).
Productivity is dependent on the temperature difference between the seawater and the condensing surface. We can maximize the rate of fresh water production per unit deck area by:
1) capturing additional heat energy (aiming the cover so it's perpendicular to the sun; providing an additional heat source, such as waste heat from another process)
2) increasing the heat absorption efficiency (adding black dyes to the water or black gravel to the base of the basin)
3) minimizing heat losses (side and bottom insulation, e.g., with sawdust)
4) reducing the volume of water to be heated
5) increasing the evaporation (place sponge or wick in basin) and condensation surface areas
6) reducing the cover temperature (blowing air or run cold seawater over the top of the glass (Sathyaraj)
7) increasing the amount of solar energy captured per unit deck area (a vertical reflector can be placed above the roof ridge of the still so that sunlight that would be otherwise lost is redirected to the still cover) (Lienhard)
Grantville Gazette, Volume 64 Page 14