Military History/red lights


Dear KHP, when I was aboard the USS Gato, a nuke fast attack, Nay time we were at periscope depth, the red lights went on in Control. Often times, even cruising in questionable waters at 400 feet, the red lights stayed on. I was told that the red lights allow a quick transition to viewing the outside via the periscope.
My question. Since the Virginia class has no periscopes, do they still use the red lights in Control? Sincerely, Dick Schlueter

Richard:  My closest associations with subs was touring the Carvallo in Galveston, and attending law school with a former guidance tech on a Boomer.  Having said that, what I have been able to find might answer the question.

Some of the reasons given are these:

The ease of transition between red and daylight on the human eye, as you said, makes the transition to viewing in the periscope easier in nightime conditions. One aspect of this has gone unmentioned, optics are two way, if the con were brightly lit at night, there is a chance that some of that light might be visible reflected through the periscope optics as a glint in the periscope lense.  So reduced red lighting in the con would prevent it.

From the conditioning aspect, it could be that when the red lights go on, the sub in in quiet running mode, noise would seem a bigger risk at periscope depths than deeper.  Since the con would be the shallowest part of the sub, red lighting might give a heads up to the crew to be more aware of the risk.

One answer I saw in searching circa 2007 said red is no longer used, in US subs since it caused "aggression" (political correctness run amok?)  They rig for low light instead.  Blue was ruled out too since it was depressing...I wonder if they normalized the survey for the effects of pitiful pay and being on a 6 month cruise with no regular poontang.  Blue also his some of the green in the waterfall displays.  So I guess they just go to low light before rising to periscope depth in evenings, nights and mornings.

Today with the mast housing IR and optic cameras, and a laser rangefinder, it does not seem that they would need to even go to low light mode.

The new masts on the Virgina class is not hull penetrating and is all electronic.  It telescopes from the sail. This allowed the con to be moved from the first deck to the second.  There will be no "gray lady" but rather two digital workstations and commanders console in its place.  Three cameras will provide the feed from the two telescoping masts. The disconnect between the con and the sail has allowed the sail to be moved forward to improve hydrodynamics as well.

To answer your question, I cannot find an answer one way or the other, but considering that the periscopes are gone and there is really no need for even low light conditions in the con, the answer is probably no.  Red is no longer used for PC reasons, nor blue. And low light is no longer needed since video feed can be viewed in any light levels.

In the berthing areas, red lights might still be used since it is less disruptive to sleeping.  Also it might also help with the sleep rythmn affects of varying work shifts.  They make alarms now that bring your bedroom lights up gradually to simulate day break and it helps to moderate the shock affect of having to wake up at odd hours to get to work on the human body.  It also helps people with brain chemistry problems like bipolar disorder and others that deal with abnormal seritonin levels and the like.

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Keith H. Patton


I can answer questions pertaining to weapons and tactics, personalities, battles, and strategies in european and U.S. history.


I was a history major, and had done extensive research in the subject area. I have designed and tested numerous computer games for various
historical periods.

B.A History M.S. Science
I have had the opportunity to live abroad and walk numerous battlefields both in the United States, Europe, and the Pacific.

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