The physical design and internal mechanics of a periscope has changed quite a bit over the years, but there’s one thing that still remains the same: in order to see what’s going on above the water even the most high-tech modern periscope still has to poke it’s little head out above the surface. And when you’re a military machine whose main goal is stealth that isn’t exactly a smart move. That’s why, for at least a decade, some scientists and engineers have been trying to figure out how to build a virtual periscope. One that can see what’s happening all around without having to come up for air. And they’re starting to make some significant and exciting progress.
An Extremely Brief History of Periscopes
According to the US Navy, the first periscope was designed in 1854 by a French chemist named Edme Hippolyte Marie-Davie. It was simply a long tube with mirrors set at 45 degrees angles at each opening. There were several attempts to perfect the design through the following decades--among them a 65-foot, 130-ton tube set with eight prisms designed by American John Holland in 1900, which gave the viewer a very dim 360 degree view of the horizon and could actually be rotated.
The modern periscope, or, at least, the one we all remember from Looney Toons, was a perfected version of Holland’s design. Patented in 1911 by Dr. Frederick O. Kollmorgen, the new version used two telescopes instead of a series of lenses (or prisms). Because it didn’t need prisms at the opening or a series of lenses throughout, the new periscope could be built at a variety of lengths and its opening above the surface could be much smaller. Kollmorgen started a company to develop and update his telescope design and, in fact, the company he created (called Kollmorgen) still exists today.
Kollmorgen’s original design went through several upgrades through the years--adding night vision, star pattern recognition systems, optical magnification, and antennas for satellite communication, but the overall concept mostly remained the same. Then, in the 1960s, the US Navy created the Type 18 periscope, which added television cameras that allowed its images to be displayed anywhere on the submarine and also recorded.
In modern US submarines, beginning around 2004 on all Virginia-class attack subs, the periscopes were replaced by photonics masts. These are telescoping arms that have visible and infrared digital cameras at the top. Since they don’t use mirrors or telescopes, there is no need for the control room to be located directly below the masts anymore. Because of this, the Navy has relocated these sub’s operations area away from the hull and down one deck where there is a lot more space.