Simon Lake experimented with boats that ascended vertically according to negative or positive buoyancy controlled by pumps and tanks.
John Holland's boats were given neutral buoyancy by admitting water to balance the weight of the boat with the weight of water it displaced. With diving planes and a constant source of power, Johm Holland's boat could dive and surface on diagonal lines.
John Holland Submarine Diving
John Holland's principle, with some alternatives for fast diving and surfacing, is still used by modern submarines.For all its innovations, the USS Holland had at least one major flaw; lack of vision when submerged. The submarine had to broach the surface so the crew could look out through windows in the conning tower. Broaching deprived the Holland of one of the submarine's greatest advantages, stealth.
The Periscope
Lack of vision when submerged was eventually corrected when Simon Lake used prisms and lenses to develop the omniscope, forerunner of the periscope.Sir Howard Grubb, designer of astronomical instruments, developed the modern periscope that was first used in Holland-designed British Royal Navy submarines. For more than 50 years, the periscope was the submarine's only visual aid until underwater television was installed aboard the nuclear powered submarine USS Nautilus.
- More on John Holland
- Photo of USS Holland (SS-1)
- John Holland (1841-1914)
- John Holland - Submarine Inventor
