Andy Dinsdale – Adjusting your eyes to use a periscope
One of the primary sensors, going back to the whole point of a submarine, is to know what else is going on around. When a submarine is deep, the primary sensor is sonar, and that works really well deep, and when you’re in steady water. The problem is as you come up to the surface, or towards the surface, the water gets more messy and it becomes more uncertain, so the sonar doesn’t work well near the surface ‘cos you’ve got lots of wave noise and things like that, so you rely less … it still works but you rely less on the sonar because it’s deadened by surface noise and things like that.
So, one of the primary sensors when you’re at periscope depth, by definition is the periscope. Now, there’s different sensors on the periscope, but one of the best sensors is having a look. So, the reason why you take time and a lot of thought goes into going back to periscope depth, is what you’ve absolutely got to make sure is that the person, whoever it is that’s on the periscope, when they first get to periscope depth, can see, because that’s the time when again, on moving things, you do a quick all round look to make sure there’s nothing close because you do get examples where things you didn’t realise they were there and all of a sudden you’ve got to go down really quickly, so what you’ve got to do is really make sure that the person who’s going to be the first one on the periscope, his, or her nowadays, eyes are accustomed to the light outside, so that’s why you go through the white light.
Now, the reality is if it’s daylight outside, you’ve no need to change the light, so it’s less so about worrying about what’s being transmitted out, it’s more really about getting the first person that’s going, or everyone that goes on the periscope, getting their eyes accustomed to what they’ll be seeing through the periscope. It’s more about getting their eyes trained and red lighting at times and sometimes you know, what we call ‘black lighting’, so turn all the lights off, ‘cos if you know it’s going to be a really dark night out there, and certainly on the T-Class you have curtains around the periscopes because again it’s interesting certainly when you’re operating at night, you’ve things like, again it’s like looking at the TV, little LEDs like that.
That’s actually a non-starter in a Control Room ‘cos that just blinds you. Lots of those around, lots of computer screens and things like that and that’s why particularly if you’re operating in the middle of nowhere at night, you’ve got to get used to seeing in the dark and getting your eyes accustomed to seeing in the dark.
Somebody shining an LED like that just screws your night vision straight away. It’s hard work actually and that’s why certainly in dark nights when you’re away wherever you are, you’ll tend to do no more than 10 -15 minutes on a periscope because it’s really hard to concentrate where you’re effectively looking at that, and it’s really hard to look at blackness and …
Simon: And if there’s waves crashing over the periscope.
Yes, waves can be a challenge, and likewise again in the middle of wherever you are, whether it’s a clear night, a dark night, even simple things like being able to see the horizon. And knowing where the horizon is.