# How strong is the glass window on military submarines? **URL:** \ **Category:** Factual Questions\ **Created:** [May 11, 2019, 4:10am UTC](https://boards.straightdope.com/t/how-strong-is-the-glass-window-on-military-submarines/833817 "2019-05-11T04:10:50Z")\ **Posts on this page:** 20\ **Page:** 2
**Author:** ![JRDelirious](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/jrdelirious/32/9531_2.png) [@JRDelirious](https://boards.straightdope.com/u/JRDelirious)\ **Post date:** [May 12, 2019, 3:05am UTC](https://boards.straightdope.com/t/how-strong-is-the-glass-window-on-military-submarines/833817/21 "2019-05-12T03:05:29Z")
Also, there is wide variation in whether or not you put windows in the sail. In [this other class of sub](https://i.pinimg.com/originals/ec/2f/ea/ec2fea381be07d349e9331dc3400dc15.jpg), you may notice, the sail itself is windowless so while surfaced the watch-standers (and smokers) get to poke their heads above the top old-style, with a pop-up barrier to keep them from getting splashed too badly. Meanwhile in the OP sub you can see that you have that going on at the very top, _plus_ then the level with windows immediately below, probably to accommodate surfaced watch standing in bad weather. ---
**Author:** ![Walken\_After\_Midnight](https://avatars.discourse-cdn.com/v4/letter/w/b487fb/32.png) [@Walken\_After\_Midnight](https://boards.straightdope.com/u/Walken_After_Midnight)\ **Post date:** [May 12, 2019, 3:26am UTC](https://boards.straightdope.com/t/how-strong-is-the-glass-window-on-military-submarines/833817/22 "2019-05-12T03:26:01Z")
The dorsal fin of marine animals helps stabilize the animal against rolling, as well as assisting in sudden turns. Does a submarine’s “sail” - called a “fin” in European/Commonwealth usage - assist the submarine at all in these areas? ---
**Author:** ![Alessan](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/alessan/32/465_2.png) [@Alessan](https://boards.straightdope.com/u/Alessan)\ **Post date:** [May 12, 2019, 5:40am UTC](https://boards.straightdope.com/t/how-strong-is-the-glass-window-on-military-submarines/833817/23 "2019-05-12T05:40:44Z")
> [@Whack-a-Mole](#): > > It could be as you say. > > The reason is to have something that sticks well out of the water when surfaced. > > If it was a bullet shaped tube no one would be able to exit the sub except in the calmest of water. When does a modern nuclear sub ever need to surface outside a dock? ---
**Author:** ![AK84](https://avatars.discourse-cdn.com/v4/letter/a/85e7bf/32.png) [@AK84](https://boards.straightdope.com/u/AK84)\ **Post date:** [May 12, 2019, 8:53am UTC](https://boards.straightdope.com/t/how-strong-is-the-glass-window-on-military-submarines/833817/24 "2019-05-12T08:53:01Z")
> [@JRDelirious](#): > > Also, there is wide variation in whether or not you put windows in the sail. In [this other class of sub](https://i.pinimg.com/originals/ec/2f/ea/ec2fea381be07d349e9331dc3400dc15.jpg), you may notice, the sail itself is windowless so while surfaced the watch-standers (and smokers) get to poke their heads above the top old-style, with a pop-up barrier to keep them from getting splashed too badly. Meanwhile in the OP sub you can see that you have that going on at the very top, _plus_ then the level with windows immediately below, probably to accommodate surfaced watch standing in bad weather. The Russians will often need their lookouts to have protection from the elements in Murmansk and Vladivostok. The American don’t at Pearl Harbour and even at Groton or Norfolk, a heavy jacket and mittens will suffice. > [@Alessan](#): > > When does a modern nuclear sub ever need to surface outside a dock? As stated the tower is for the lookouts. Subs will need to surface when the local water depth in insufficient for safe underwater operations, like in coastal areas, straits or when transiting canals. ---
**Author:** ![Alessan](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/alessan/32/465_2.png) [@Alessan](https://boards.straightdope.com/u/Alessan)\ **Post date:** [May 12, 2019, 9:35am UTC](https://boards.straightdope.com/t/how-strong-is-the-glass-window-on-military-submarines/833817/25 "2019-05-12T09:35:32Z")
> [@AK84](#): > > As stated the tower is for the lookouts. Subs will need to surface when the local water depth in insufficient for safe underwater operations, like in coastal areas, straits or when transiting canals. Why not just put some cameras on retractable mast? Why do you need Mark 1 eyeballs up top? Also, do missile subs ever enter shallow waters? Why? Isn’t staying hidden their number one priority? ---
**Author:** ![JRDelirious](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/jrdelirious/32/9531_2.png) [@JRDelirious](https://boards.straightdope.com/u/JRDelirious)\ **Post date:** [May 12, 2019, 1:47pm UTC](https://boards.straightdope.com/t/how-strong-is-the-glass-window-on-military-submarines/833817/26 "2019-05-12T13:47:00Z")
> [@Alessan](#): > > Why not just put some cameras on retractable mast? Why do you need Mark 1 eyeballs up top? > > Also, do missile subs ever enter shallow waters? Why? Isn’t staying hidden their number one priority? 1. Heck if I know, ask the Navy. But I suppose same reason surface vessels don’t go to just 360-round cameras fed to the command room and still have topside lookouts - redundancy and, it is hoped, human ability to recognize something wrong. Even then they don’t always manage to prevent the Loud Crunching Sound. 2. Nearing and entering port. Which in turn means you may be around traffic, in a low-profile dark vessel so the more you want to see them in time. ---
**Author:** ![DesertDog](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/desertdog/32/11503_2.png) [@DesertDog](https://boards.straightdope.com/u/DesertDog)\ **Post date:** [May 12, 2019, 1:51pm UTC](https://boards.straightdope.com/t/how-strong-is-the-glass-window-on-military-submarines/833817/27 "2019-05-12T13:51:56Z")
> [@Northern\_Piper](#): > > What’s the difference? 😕 The sail is the whole thing sticking above the hull. The [conning tower](https://en.wikipedia.org/wiki/Conning_tower#Submarines) is (was, actually) the part where the people lived. The rest of the sail was filled with stuff that didn’t mind getting wet. > [@Wiki](#): > > As improvements in technology allowed the periscopes to be made longer it became unnecessary to raise the conning station above the main pressure hull. USS Triton (laid down 1956) was the last American submarine to have a conning tower. The additional conning tower pressure hull was eliminated and its functions were added to the command and control center. Thus it is incorrect to refer to the sail of a modern submarine as a conning tower. If you read the whole article I linked to, you’ll find that surface ships had a conning tower too, once upon a time. It was just not as obvious, being buried in the superstructure. ---
**Author:** ![Bert\_Nobbins](https://avatars.discourse-cdn.com/v4/letter/b/aeb1de/32.png) [@Bert\_Nobbins](https://boards.straightdope.com/u/Bert_Nobbins)\ **Post date:** [May 12, 2019, 2:49pm UTC](https://boards.straightdope.com/t/how-strong-is-the-glass-window-on-military-submarines/833817/28 "2019-05-12T14:49:40Z")
> [@CalMeacham](#): > > The periscope was an incredible piece of engineering – it wasn’t just a lens at the top and a lens at the bottom with a couple of mirrors to redirect the light. That whole tube was crammed with relay lenses and the like. Each lens had to be anti-reflection coated, or else Fresnel losses at that many surfaces would cause all the light to be reflected away. Periscope engineering was indeed a highly developed art. I have looked through the periscopes of [https://www.historicdockyard.co.uk/site-attractions/off-site-attractions/hms-alliance](https://www.historicdockyard.co.uk/site-attractions/off-site-attractions/hms-alliance) and the optical quality and the brightness of the image were stunning. In a different league from ordinary binoculars etc. ---
**Author:** ![JRDelirious](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/jrdelirious/32/9531_2.png) [@JRDelirious](https://boards.straightdope.com/u/JRDelirious)\ **Post date:** [May 12, 2019, 7:31pm UTC](https://boards.straightdope.com/t/how-strong-is-the-glass-window-on-military-submarines/833817/29 "2019-05-12T19:31:49Z")
> [@DesertDog](#): > > The sail is the whole thing sticking above the hull. The [conning tower](https://en.wikipedia.org/wiki/Conning_tower#Submarines) is (was, actually) the part where the people lived. [Illustrated here.](http://www.bergall.org/subguts.jpg) Above the conning tower were the exposed topside bridge, from which you drove the boat while surfaced, and masts for antennae, periscopes etc. ---
**Author:** ![Gray\_Ghost](https://avatars.discourse-cdn.com/v4/letter/g/c0e974/32.png) [@Gray\_Ghost](https://boards.straightdope.com/u/Gray_Ghost)\ **Post date:** [May 12, 2019, 7:45pm UTC](https://boards.straightdope.com/t/how-strong-is-the-glass-window-on-military-submarines/833817/30 "2019-05-12T19:45:56Z")
> [@scr4](#): > > It’s possible to design a window to withstand the pressure if they really needed to. [This submersible](https://en.wikipedia.org/wiki/Submersible#/media/File:Ictineu_3_submersible.JPG) has a huge window and can go down to 3900 ft, deeper than most military submarines. Even our favorite, “two men, for twenty minutes,” submersible, the bathyscaphe _[Trieste](https://www.navalhistory.org/2012/01/25/trieste-achieves-depth-record)_, had a window. It was a conical piece of Plexiglas 4.5 inches in diameter, and 5.9 inches thick. And it still [famously cracked](https://www.telegraph.co.uk/men/the-filter/true-story-behind-deepest-dive-history/) at about 31,000 feet deep during Walsh and Piccard’s trip to the Challenger Deep. ---
**Author:** ![Declan](https://avatars.discourse-cdn.com/v4/letter/d/ecae2f/32.png) [@Declan](https://boards.straightdope.com/u/Declan)\ **Post date:** [May 12, 2019, 8:38pm UTC](https://boards.straightdope.com/t/how-strong-is-the-glass-window-on-military-submarines/833817/31 "2019-05-12T20:38:04Z")
> [@Alessan](#): > > Also, do missile subs ever enter shallow waters? Why? Isn’t staying hidden their number one priority? Since you said missile subs, the Russians do , or at least did for their bastion patrols. They would be entering shallow waters in a mine field, so the boomer would be riding higher. Older generations of Russian boomers used the sail for housing the SLBM’s. ---
**Author:** ![MEBuckner](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/mebuckner/32/2896_2.png) [@MEBuckner](https://boards.straightdope.com/u/MEBuckner)\ **Post date:** [May 12, 2019, 8:55pm UTC](https://boards.straightdope.com/t/how-strong-is-the-glass-window-on-military-submarines/833817/32 "2019-05-12T20:55:46Z")
> [@Alessan](#): > > Also, do missile subs ever enter shallow waters? Why? Isn’t staying hidden their number one priority? I read _Big Red: Three Months on Board a Trident Nuclear Submarine_ by Douglas Waller not too long ago; the process of coming out of the [submarine base at King’s Bay](https://www.google.com/maps?ll=30.781667,-81.535&q=30.781667,-81.535&hl=en&t=m&z=15) here in Georgia is apparently fairly tricky (and definitely involves threading their way through some narrow and shallow channels). I would imagine the [naval base over in Bangor, Washington](https://www.google.com/maps/place/47%C2%B043'27.8%22N+122%C2%B043'12.2%22W/@47.7244,-122.720047,12z/data=!4m5!3m4!1s0x0:0x0!8m2!3d47.7244!4d-122.720047?hl=en) (the other base where U.S. ballistic missile subs are home-ported) requires similar maneuvering. It’s only after they’re out to sea that they dive, and vanish. ---
**Author:** ![Alessan](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/alessan/32/465_2.png) [@Alessan](https://boards.straightdope.com/u/Alessan)\ **Post date:** [May 13, 2019, 12:01pm UTC](https://boards.straightdope.com/t/how-strong-is-the-glass-window-on-military-submarines/833817/33 "2019-05-13T12:01:02Z")
Here’s an idea: instead of a big, useless sail, bolt a cherry-picker onto the sub instead. Just get a guy to stand on a platform, have a hydraulic crane lift it up 10-20 feet, \*et voila \*- you’ve got a lookout. ---
**Author:** ![TimfromNapa](https://avatars.discourse-cdn.com/v4/letter/t/d26b3c/32.png) [@TimfromNapa](https://boards.straightdope.com/u/TimfromNapa)\ **Post date:** [May 13, 2019, 8:29pm UTC](https://boards.straightdope.com/t/how-strong-is-the-glass-window-on-military-submarines/833817/34 "2019-05-13T20:29:20Z")
What? No one is asking about the huge windows on the Seaview? ---
**Author:** ![dstarfire](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/dstarfire/32/5762_2.png) [@dstarfire](https://boards.straightdope.com/u/dstarfire)\ **Post date:** [May 13, 2019, 9:00pm UTC](https://boards.straightdope.com/t/how-strong-is-the-glass-window-on-military-submarines/833817/35 "2019-05-13T21:00:21Z")
> [@Alessan](#): > > Seriously, though. Why does a submarine even need a superstructure? Why can’t it just be a smooth, symmetrical cylinder? Seems to be that taking the lump away would make it more hydrodynamic and stealthy. So what’s it there for? It gives you a place to put antennas, periscope masts and the like that need to be above the waters surface to work correctly. A place that produces a less wake and is less obvious than the main body of a submarine. Also, I know ordinary pleasure yachts are a lot easier to manuever from the upper bridge (which is ~10 feet above the normal bridge). I imagine the same is true for military subs. ---
**Author:** ![MarvinKitFox](https://avatars.discourse-cdn.com/v4/letter/m/7ba0ec/32.png) [@MarvinKitFox](https://boards.straightdope.com/u/MarvinKitFox)\ **Post date:** [May 14, 2019, 5:58am UTC](https://boards.straightdope.com/t/how-strong-is-the-glass-window-on-military-submarines/833817/36 "2019-05-14T05:58:09Z")
> [@Dana\_Scully](#): > > What I’m getting at is, what is the **SAIL**? is it the conning tower? or what? I’m not connected with the military so I don’t know these terms. google “submarine sail” It takes about 3 seconds. Which is much, _much_ less than showing your ignorance here. ---
**Author:** ![engineer\_comp\_geek](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/engineer_comp_geek/32/504_2.png) [@engineer\_comp\_geek](https://boards.straightdope.com/u/engineer_comp_geek)\ **Post date:** [May 14, 2019, 6:55am UTC](https://boards.straightdope.com/t/how-strong-is-the-glass-window-on-military-submarines/833817/37 "2019-05-14T06:55:30Z")
**Moderator Note** > [@MarvinKitFox](#): > > google “submarine sail” > > It takes about 3 seconds. > Which is much, _much_ less than showing your ignorance here. Telling someone to google something is not acceptable in GQ. Maybe you should have taken a few seconds to read the General Questions FAQ: > [@General Questions FAQ](#): > > By the same token, we aren’t interested in hearing about how stupid the question was because a search could have answered the question. Nor are we interested in hearing how simple it was for another poster to find the answer in a search engine. If it’s that simple to find the answer, go ahead and post the answer. ---
**Author:** ![Dana\_Scully](https://avatars.discourse-cdn.com/v4/letter/d/5daacb/32.png) [@Dana\_Scully](https://boards.straightdope.com/u/Dana_Scully)\ **Post date:** [May 14, 2019, 2:15pm UTC](https://boards.straightdope.com/t/how-strong-is-the-glass-window-on-military-submarines/833817/38 "2019-05-14T14:15:13Z")
> [@MarvinKitFox](#): > > google “submarine sail” > > It takes about 3 seconds. > Which is much, _much_ less than showing your ignorance here. Oh Marvin, I don’t mind showing my ignorance. I AM a civilian and an old lady, and I don’t mind asking questions; that’s how you learn things (except–in your case–manners, it would seem). ---
**Author:** ![Dana\_Scully](https://avatars.discourse-cdn.com/v4/letter/d/5daacb/32.png) [@Dana\_Scully](https://boards.straightdope.com/u/Dana_Scully)\ **Post date:** [May 14, 2019, 2:56pm UTC](https://boards.straightdope.com/t/how-strong-is-the-glass-window-on-military-submarines/833817/39 "2019-05-14T14:56:11Z")
> [@Dana\_Scully](#): > > Oh Marvin, I don’t mind showing my ignorance. I AM a civilian and an old lady, and I don’t mind asking questions; that’s how you learn things (except–in your case–manners, it would seem). ETA: Maybe this is the part of the FAQ’s he didn’t read: _ **We have one guiding principle: Don’t be a jerk.** _ ---
**Author:** ![Northern\_Piper](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/northern_piper/32/5304_2.png) [@Northern\_Piper](https://boards.straightdope.com/u/Northern_Piper)\ **Post date:** [May 14, 2019, 3:47pm UTC](https://boards.straightdope.com/t/how-strong-is-the-glass-window-on-military-submarines/833817/40 "2019-05-14T15:47:27Z")
> [@Dana\_Scully](#): > > (except–in your case–manners, it would seem). Made me laugh! 😃 [Previous page](https://boards.straightdope.com/t/how-strong-is-the-glass-window-on-military-submarines/833817.md?page=1) [Next page](https://boards.straightdope.com/t/how-strong-is-the-glass-window-on-military-submarines/833817.md?page=3)