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Computers That Thrive in Salty, Humid Environments?
To start us out, frostman asks: "A friend of mine is living on a sailboat, and would like to set up a nifty computer system. It doesn't need to be too powerful, but it should be small, rugged, fairly quiet, and cheap. He has a standard PII/400 mid-tower system he can gut for parts (400Mhz would probably be enough). He wants to do normal internet stuff, watch DVD's, listen to MP3's (with good speakers)... and he needs it to run on 12 volts when he's sailing. Any suggestions from the hardware gurus on Slashdot?"
websensei continues with this query: "I am about to become a full-time live-aboard on my sailboat. I'm in the process of selling all my machines and plan to spend about $2000 on a new laptop for the boat. I'll use it for work and play (movies, gaming, TV via USB TV tuner?) etc. Please share any advice/experiences relating to computing on boats or other harsh/damp environs."
And last, but not least, Alioth asks about fishes, not boats: "How about computers in fish factories? Not only do we have to contend with the room being jetwashed, but the atmosphere is very salty. I've been looking at stainless steel enclosures - what's their salt water resistance like, not just the stainless parts, but the parts that fasten the stainless parts together, not to mention being able to keep the computer cool as well (meaning it's got to vent somewhere)?"
Just as an opening thought, I'd remove as many fans as possible since they would be the first to go.
Maybe something based on the Cyrix 933 processor? They run a lot cooler, and would require only a heatsinc.
The less moving parts the better.
The US Navy generally uses ruggedized notebooks. In other electronics, the US Navy generally makes sure that they are hermetically sealed and test a few with a salt-water spray before deploying them.
I remember that there's a common problem with the electrical systems on boats - Since the "ground" is just the hull of the boat, and it has to discharge through the salt water, there's an abnormally-significant problem with corrosion of metal electrical contacts on a lot of salt-water vessels. I have no idea what effect this would have on a computer, and don't have any intentions of finding out anytime soon. :)
.... um, i lost you after "0110100001101001".
It would probably be a bit more realistic to find a manufacturer of a box which is conductively cooled to the outer (sealed) casing. That takes care of corrosion issues in the computer itself; the keyboard, mouse and display will have to take care of themselves, and of course you're going to have to use something like a USB floppy/CD drive to avoid penetrations through the casing.
Scientists restrict study to entire physical universe; creationist
Yes. Imagine HP Vectra computers on shock-proof feet to protect them from engine vibrations. We often used to use these as part of our ISIS engine management systems in engine control rooms: hot, steamy, smelling of saltwater and diesel fuel.
The Vectras lasted just fine. I think any other quality computer would, too. The biggest killer is the vibrations; the heat, humidity and salt are no worse than if you lived in, say, Tampa, with no air conditioning.
Equipment specifically built for a marine environment is always very tough, but that's the same for almost anything sold to industry instead of consumers. Industry more often wants quality; consumers claim they want quality and then run out and buy Samsung TV sets.
Here's a radar system with a 68000-based computer doing the video processing. Here's a Great Lakes bulker, pretty small potatoes in the marine world, yet it still has a diesel engine approximately four stories tall.
Fire and Meat. Yummy.
a friend of mine had a bunch of hard drives die on his boat. The solution was simply to have the drive vertical parallel to the length of the boat. the problem was caused by the spinning drive platter behaving like a gyroscope and resisting the motion of the boat. with a lengthways vertical install, you remove most of the spin related gyroscopic effects
I work at a neutral buoyancy facility at the University of Maryland -- neutral buoyancy is how NASA trains astronauts to perform EVAs. It uses water to simulate weightlessness. Instead of training astronauts, we design robots to repair broken satellites and to assist astronauts on orbit. As a consequence, we put quite a few computers in very moist environments, and they actually get doused from time to time. The environment isn't salty, but it is highly chlorinated and really warm (the water is kept at around 90 degrees, for reasons I won't get into).
We tend to use embedded machines - PC/104, CompactPCI, etc. These systems are essentially the same technology as desktop machines, the same processors, memory, etc, but have a smaller footprint and tend to use less power. They are remarkably robust. We've had CPU boards that are actually flooded, with the power on. You turn everything off, douse it with WD-40 to dry it out (WD-40 was originally developed to prevent water-based corrosion in electronics, *not* as a lubricant), let it sit for 24 hours, and more often than not it's just fine.
The lesson from this I think is that unless the machine is going to be actually in the spray from the boat, you're going to be okay with a quality out-of-the-box desktop machine. Put one of those rubber membranes over the keyboard - keyboards do tend to die when they get wet. If the machine gets significantly wet, dry it out and maybe hit it with WD-40 or some other water repellant. Other than that don't worry about it.
My time in Uncle Sam's canoe club was as a keypunch operator / computer operator on USS Midway, CV-41. The computer was a tape system (no disks) with card input. The tape drive had rubber seals around the doors and various parts, and (rumour had it) could operate under water. Now, since we were one deck under the flight deck, I always figured I didn't want to be around when that was necessary.
After the evacuation of Saigon (April 1975), Radio Hanoi called us pirates for not returning all the planes and helicopters flown out of country by the escapees. Our captain promptly broke out the Jolly Riger.
So I am a real high seas pirate, by no less an authority than Radio Hanoi, and we had a computer built to operate under water!
Infuriate left and right
I just returned from the Pacific Cup race from San Francisco, CA to Kaneohe, HI and was in charge of the computers. We carried two laptops primarily as backup and to use with the Iridium phone but the main computer was a Capuccino from Think Geek.
We mounted a Tote Vision monitor on an adjustable arm at the nav station and controlled it with a wireless keyboard and wireless mouse. The Tote also includes a TV receiver so you can eliminate one other piece of equipment.
For our use we needed more serial ports so we got a USB-serial converter box which gave us a total of one on the PC plus 4 external. For the race we collected HF weatherfax using mScan meteo software. The software controlled an ICOM PCR-1000 general coverage receiver via. the serial port and used the internal sound card to receive the weatherfax data.
Another serial port was dedicated to the B&G tactician software to B&G instrument connection.
The next port provided NMEA GPS input to the Nobletec navigation program and another provided general NMEA instrument data to Nobletec (the Nobletec software can display maps as well as a console with wind info, boat speed, heading, water temperature and whatever else your instruments collect).
Finally, another port sent NMEA navigation info back from Nobletec to the onboard instruments for display to the driver (range/bearing to waypoint, cross track error, etc.)
The whole thing worked great (we won our division!).
The advice is somewhat obvious - keep the computer dry. We mounted the PC and Icom behind the breaker panel as electrical areas are generally pretty dry on a boat. The whole thing runs on 12v so we didn't need to run the ship's inverter. (Capuccino uses a 12v-18v adapter, Tote is 12v native. The Canon printer is 13.6v and worked great only when the batteries were fully charged).
Heat build-up is a problem on hot days or in the tropics so we added a fan to pull air through the instrument/electrical compartments. This solved our heat-related crashes.
Access to the computer requred twisting two screw latches so it was pretty easy but not convenient if you need to access the CD a lot. It's likely that you could find a spot near your nav table to mount the mini-PC where you could access the disk easily.
I know many people who live and work on their boats. Most use laptops but one uses regular PCs with a huge LCD monitor. None have really had any trouble but they don't leave the computers where they are exposed to the elements. Usually a boat that is large enough to live on has some dry areas.
As to the other question, you need industrial electronic enclosures. I don't recall which companies make them but my former roommate worked on systems that were used in food packing and they used standard enclosures designed to withstand the 180 degree 1000psi pressure wash that they used to clean the processing equipment. Google??
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"You are not remembered for doing what is expected of you." - Atul Chitnis
Or I should say, it works too well. The system worked great initially, but pretty soon the oil got in between the connections of all the components that weren't soldered or printed on the mainboard, and thus rendered each of those components useless (CPU, memory, video card, and anything else in the PCI slots).
The only way to do a mineral cooled system would be to solder everything down. Of course, then you couldn't upgrade anything. I guess that might work for a laptop (how many people actually upgrade a CPU or a video card on a laptop?), but the memory would need to be maxed out, and then you have the extra weight of all the mineral oil in there to lug around. So maybe not.
Check carefully into the power supply for on-ship electronics. One of the interesting things with computers on US Navy ships is the power supplies they have. Navy ships do things slightly differently for supplying electricity.
The guarantee for shipbaord power is very different from your standard land-based poewr company. Shipboard power is (or at least was 15 years ago) guaranteed as "the difference between these 2 wires is 120Volts, at 60Hz". Note that carefully. No reference to what the actual voltage levels will be, just the voltage difference between the 2 wires.
Most computer power supplies assume "the difference between these 2 wires is 120Volts (actually 116volts, I think) AND the actual voltage levels will be approximately 0volts and 120volts".
The Navy burned out a lot of computer power supplies before some bright boy realized this. Having voltage levels of -80volts and +40volts did bad things.
There's a reason MILSPEC costs as much as it does.
Of course, if you're looking to power it off a 12VDC line, this isn't really a concern, is it?
This is my sig. There are many like it but this one is... Oops. Frank, I've got your sig again! Where's mine?
I worked on the software for one of the first onboard PC systems in the US navy (and no, not the crappy CAE NT system that BSOD-ed and required the ship to be towed). There's a blurb about the overall project at http://198.65.138.161/military/systems/ship/ddg-51 -flt2a.htm , but it doesn't mention my stuff (and does mention that they will eventually be using the CAE system mentioned above. They call it "smart ship". :-)
In general, the requirements for these systems are unreal. Among other things, they have to be able to handle 100G's of shock and vibration (I'm not a Mechanical Engineer, but that sounds damn extreme to me). This pretty much means no moving parts, so hard drives have to be solid-state. We went with a solid-state PCMCIA card that looks like a hard-drive to the system for our boot drive. A trackball was used instead of a mouse for the control device, the keyboard was built into the cabinet, and the whole cabinet was fitted huge shock absorbers under it and inside it.
One GUI vendor was disqualified on the sole basis that they required a dongle which would have needed all sorts of extra bracing to keep it from snapping off. That's about the best example I've ever seen of copy-protection costing someone sales.
See, what they need is a nice digital projecter. Leave the computer inside, but output the screen contents across the sail for easy viewing.
- billn
There are some specialized resin-ceramic coats that have this property, and some of them aren't brittle at all, adding to the shock-absorption of the coated components.
How about nonelectrically-conductive, nonbrittle, heat conductive, and transparent; has that been achieved yet?
How about lucite with only heat sink surfaces exposed? If the heat sink and the lucite had the same thermal expansion properties, then the thing would be likely to stay sealed. Otherwise you would need some gasketing compound at their boundaries.
Lots of suggestions about just keeping a computer somewhere dry but in a small sailboat, bare minimum for one person to live aboard for an extended period? Good luck finding anywhere that doesnt accumulate salt deposits over time if its open to the atmosphere. Problem is, once those deposits are there (even if they are not visible to the eye) that surface will never be truly dry, even on the hottest day. Nowhere is safe. The best deckheads develop persistent small leaks over time, particularly near the gunwales or worse still by the foot of a deck-stepped mast. Most "watertight" hatches on sailboats only qualify for that name on the grounds that if you get a wave over the deck most of it will drain off rather than go through. Assuming the craft goes anywhere other than the occasional brief trip around the harbour the phrase "dry stowage" on a boat this size is at best a relative term.
Now look at larger vessels. In general if they are large enough to have a genuine superstructure (ie you can be "indoors" with your feet no lower then deck level) then you stand a chance of keeping dry stowage dry and might get away with trying to protect a regular machine.
The harder you sail the worse it is of course. The engineers that have posted are absolutely right about the impacts and vibes and again the larger vessels have it easier (If your deckhead doesnt leak now, dont worry. After a couple of seasons pounding like this, it will.) At one point I saw the same piece of (genuine marine-quality) electronics installed on 2 craft. One was the 24-footer that my dad & I sailed all over the Irish Sea, the other was 42-foot motor-sailer that a friend had. My dad & I raced in ours, our friend took leisurely coastal cruises, so long as the weather forecast was perfect. Guess which piece of electronics died first?
I had a