Periscope breaks above 10 knots is that real?

PatrickWarner · 06-10-19, 11:05 AM

Is it really true that travelling at more than around 10 knots breaks the periscope on a submarine?

I guess it must be (?) but it seems strange that after all this time they haven't figured a way to make it work at faster speeds.

Is that because of technology limitations or is it more that they don't see a need to have it working at higher speeds?

FPSchazly · 06-10-19, 01:29 PM

Quote:

Originally Posted by PatrickWarner

Is it really true that travelling at more than around 10 knots breaks the periscope on a submarine?

I guess it must be (?) but it seems strange that after all this time they haven't figured a way to make it work at faster speeds.

Is that because of technology limitations or is it more that they don't see a need to have it working at higher speeds?

There's not really much of a need. At slower speeds, it already starts to make a wake that can be quite visible from a distance. If you're running that fast, you're probably not hunting either, you're probably evading. I'm sure it's also a physics limitation. The periscope is of such and such a thickness and it's quite long so the water flow would put quite a torquing moment on the metal.

ET2SN · 06-10-19, 09:54 PM

In reality, no.

The scope barrel is fairly strong and its rated to the same depth as the hull (the scope barrel can be thought of as being separate from the rest of the sub).

In practical terms, there are some speed limits.

The only thing that attaches the barrel to the boat are the hull packing gland (the water tight seal that allows the barrel to turn) and two small (but long) hydraulic lifting cylinders.
You can raise the scope at higher speeds but its one heck of a ride once you grab the handles and look into the eye piece (the odds are good you'll wind up with a black eye). Otherwise, you don't want to risk damaging the packing gland or the lift rods.

FPSchazly · 06-11-19, 07:04 AM

Quote:

Originally Posted by ET2SN

In reality, no.

The scope barrel is fairly strong and its rated to the same depth as the hull (the scope barrel can be thought of as being separate from the rest of the sub).

In practical terms, there are some speed limits.

The only thing that attaches the barrel to the boat are the hull packing gland (the water tight seal that allows the barrel to turn) and two small (but long) hydraulic lifting cylinders.
You can raise the scope at higher speeds but its one heck of a ride once you grab the handles and look into the eye piece (the odds are good you'll wind up with a black eye). Otherwise, you don't want to risk damaging the packing gland or the lift rods.

Don't listen to me, listen to this guy

ET2SN · 06-11-19, 03:08 PM

Well, its not like a junior OOD ever ordered the boat up to PD and forgot to check the speed before he raised the scope.

BTW, that fairing below the scope barrel isn't directly connected to it. The fairing has its own hydraulic lines and its designed to operate in sequence with the scope's hydraulics. If you wanted to raise the scope without the fairing, all you do is shut a couple of valves.

PatrickWarner · 06-12-19, 02:40 PM

Interesting.

So why then in the game would they model the scope being permanently damaged if you raise when going above 10 knots if there's no basis for this? Seems like a strange thing for the game designer to do.

ET2SN · 06-12-19, 04:43 PM

You'd have to ask Sonalysts.

That always struck me as odd, maybe its a game play thing where you get a penalty if your attention to detail fails? Maybe they wanted to avoid the concept of "under hulling" another contact?

The truth of the matter is that you could raise and lower the scope at test depth as long as your external hydraulics had enough pressure and you were crazy enough to try it (and don't get me started on how test depth is mis-understood).

p7p8 · 06-13-19, 08:00 AM

@ET2SN you talk about hydrostatic pressure but @PatrickWarner ask about hydrodynamic pressure - its NOT the same.

Quote:

You'd have to ask Sonalysts.

That always struck me as odd, maybe its a game play thing where you get a penalty if your attention to detail fails? Maybe they wanted to avoid the concept of "under hulling" another contact?

Did you tried to raise periscope at maximum operational depth? Im sure you didn't because its possible in DW, vanilla, RA or Lwami.
Only exceeding 10 kts speed causes periscope damage - no matter your submarine depth.

06-10-19, 11:05 AM	#1
PatrickWarner Swabbie Join Date: Feb 2005 Posts: 13 Downloads: 5 Uploads: 0	Periscope breaks above 10 knots is that real? Is it really true that travelling at more than around 10 knots breaks the periscope on a submarine? I guess it must be (?) but it seems strange that after all this time they haven't figured a way to make it work at faster speeds. Is that because of technology limitations or is it more that they don't see a need to have it working at higher speeds?

06-10-19, 09:54 PM	#3
ET2SN ET2/SS Join Date: Oct 2017 Posts: 2,504 Downloads: 58 Uploads: 0	In reality, no. The scope barrel is fairly strong and its rated to the same depth as the hull (the scope barrel can be thought of as being separate from the rest of the sub). In practical terms, there are some speed limits. The only thing that attaches the barrel to the boat are the hull packing gland (the water tight seal that allows the barrel to turn) and two small (but long) hydraulic lifting cylinders. You can raise the scope at higher speeds but its one heck of a ride once you grab the handles and look into the eye piece (the odds are good you'll wind up with a black eye). Otherwise, you don't want to risk damaging the packing gland or the lift rods.

06-11-19, 03:08 PM	#5
ET2SN ET2/SS Join Date: Oct 2017 Posts: 2,504 Downloads: 58 Uploads: 0	Well, its not like a junior OOD ever ordered the boat up to PD and forgot to check the speed before he raised the scope. BTW, that fairing below the scope barrel isn't directly connected to it. The fairing has its own hydraulic lines and its designed to operate in sequence with the scope's hydraulics. If you wanted to raise the scope without the fairing, all you do is shut a couple of valves.

06-12-19, 02:40 PM	#6
PatrickWarner Swabbie Join Date: Feb 2005 Posts: 13 Downloads: 5 Uploads: 0	Interesting. So why then in the game would they model the scope being permanently damaged if you raise when going above 10 knots if there's no basis for this? Seems like a strange thing for the game designer to do.

06-12-19, 04:43 PM	#7
ET2SN ET2/SS Join Date: Oct 2017 Posts: 2,504 Downloads: 58 Uploads: 0	You'd have to ask Sonalysts. That always struck me as odd, maybe its a game play thing where you get a penalty if your attention to detail fails? Maybe they wanted to avoid the concept of "under hulling" another contact? The truth of the matter is that you could raise and lower the scope at test depth as long as your external hydraulics had enough pressure and you were crazy enough to try it (and don't get me started on how test depth is mis-understood).