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  #1  
Old 12-27-2005, 10:41 PM
633squadron 633squadron is offline
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Round thingie in a ship's windows

OK, this has been bugging me for years.

I'm a big fan of sailing, ships, navies, etc. I've never been on a big freighter/liner/navy vessel, though, but I have seen many movies and documentaries on them.

These always feature a view of the bridge, with its big windows. And often, I see in the middle of these windows something that looks like a porthole. It's round, surrounded by a wide ring or flange of some dark material, and always has a short spindle sticking through the center. Sometimes it looks like the spindle is connected to the flange by a holder.

Now for the life of me I can't figure out what this thing is for. It looks like a clear plastic record player embedded in the window. Is this some sort of heads-up radar display? A porthole (and why do you need a porthole in the middle of a window)? A 1920s-style death ray for ships?
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  #2  
Old 12-27-2005, 10:50 PM
Terrifel Terrifel is offline
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It's a windshield wiper. During a storm at sea, the disc spins at a high rate, flinging the water out to the edges and providing a clear field of vision. And it means that no one has to go out on deck to replace wiper blades during the storm.
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Old 12-27-2005, 11:13 PM
633squadron 633squadron is offline
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Quote:
Originally Posted by Terrifel
It's a windshield wiper. During a storm at sea, the disc spins at a high rate, flinging the water out to the edges and providing a clear field of vision. And it means that no one has to go out on deck to replace wiper blades during the storm.
A windshield wiper? OK, I guess, but I'm sure I've seen them on ships that also had windshield wipers on the windows. Does it have a special name, so I could look at one up close on the Web?
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Old 12-27-2005, 11:25 PM
tomndebb tomndebb is offline
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It's a clear view screen.

The window insert is rotated at a speed that does not allow rain (or snow or (it is hoped), ice) to stick to it and it also resists fogging as it always has air "moving" across it as it spins (although more recently they have begun providing heaters, as well).

(For some reason, I had thought that these were sometimes called Kent Windscreens, but I can find no support for that odd notion on-line.)
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Old 12-27-2005, 11:30 PM
Terrifel Terrifel is offline
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Originally Posted by tomndebb
(For some reason, I had thought that these were sometimes called Kent Windscreens, but I can find no support for that odd notion on-line.)
Evidently you're not entirely deluded in that regard... Picture here.

"Welcome aboard. The name's Clearview... Kent Clearview."
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  #6  
Old 12-27-2005, 11:30 PM
tomndebb tomndebb is offline
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More examples, (last three items at bottom of page). (.pdf)
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  #7  
Old 12-27-2005, 11:32 PM
tomndebb tomndebb is offline
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Ah! The Kent brand uses the word "clearview" rather than "clear view."
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Old 12-27-2005, 11:34 PM
633squadron 633squadron is offline
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Quote:
Originally Posted by tomndebb
Yep, that's it exactly. Now just to be annoying, why have this and windshield wipers as well? Or am I mistaken about the wipers?
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  #9  
Old 12-27-2005, 11:54 PM
tomndebb tomndebb is offline
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Clear views come in sizes between 300 mm and 400 mm. A ship's window is generally much larger. The clear view provides absolute clarity for an officer to stare through in really harsh conditions. For general rain squalls and spray, you'd want something to keep the rest of the wheelhouse windows clear so that everyone could look out.
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  #10  
Old 12-28-2005, 12:10 AM
Rick Rick is offline
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Quote:
Originally Posted by 633squadron
Yep, that's it exactly. Now just to be annoying, why have this and windshield wipers as well? Or am I mistaken about the wipers?
You are mistaken, what you are thinking is the wiper is actually the electrical feed to the motor. (No matter how hard they try the just can't get the electricy to jump that last 10" )
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Old 12-28-2005, 01:22 AM
First Amongst Daves First Amongst Daves is offline
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Quote:
Originally Posted by tomndebb
Clear views come in sizes between 300 mm and 400 mm. A ship's window is generally much larger. The clear view provides absolute clarity for an officer to stare through in really harsh conditions. For general rain squalls and spray, you'd want something to keep the rest of the wheelhouse windows clear so that everyone could look out.
Its not just ships - I have been on smallish power boats fitted with small versions of them. Never seen a vessel fitted with both tradtiional wipers and clearview windows, though.
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Old 12-28-2005, 01:46 AM
Tuckerfan Tuckerfan is offline
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A lot of your high end machining centers have them as well, so you can watch the machine work, while it sprays coolant/cutting fluid all over the place.
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  #13  
Old 12-28-2005, 08:21 AM
Scruloose Scruloose is offline
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Quote:
Originally Posted by 633squadron
Yep, that's it exactly. Now just to be annoying, why have this and windshield wipers as well? Or am I mistaken about the wipers?
No, you're not mistaken. Two of the ships I've served on had clearviews and wipers. Actually, just one clearview in the center window, then wipers on the remaining four front windows. The only downside to clearviews that I could tell is that on nice days when you didn't need it, much of your vision through that window was obstructed because it's always there. So it was nice having four windows without the clearview to see through unobstructed.
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  #14  
Old 12-28-2005, 08:26 AM
Scruloose Scruloose is offline
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Now that I'm thinking about it, 633squadron, if you're asking about having a clearview and wipers on the same window, then I'd guess you probably were mistaken about the wipers. You obviously wouldn't have both on the same pane.
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  #15  
Old 12-28-2005, 08:34 AM
Mr. Moto Mr. Moto is offline
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I served on a guided missile cruiser. We had two clearviews in forward facing windows on the bridge and traditional wipers on the rest of them.

That included, too, the port and starboard windows. We didn't need clearviews there, as there was always a lookout on the bridgewing, whatever the weather was like.
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  #16  
Old 12-28-2005, 08:49 AM
Ethilrist Ethilrist is offline
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Quote:
Originally Posted by 633squadron
Yep, that's it exactly. Now just to be annoying, why have this and windshield wipers as well? Or am I mistaken about the wipers?
It's the same reasoning that puts belt loops, suspender buttons, two fly buttons, a slider thingy and a zipper on dress pants: to make really, really, really sure your pants don't fall down. Or to make sure you don't run into an iceberg. Because it'd really suck to have to say, "Well, we would have missed the iceberg, but the $2 motor on the clearview burned out and we couldn't see where we were going, so... sorry..."
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  #17  
Old 12-28-2005, 10:32 AM
Pushkin Pushkin is offline
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Are similar devices used for lorry wing mirrors as well?
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