March 4, 2017: Modern warfare in general and naval warfare in particular has been propelled by the search for technological advantages. Since the 15th century the navy with the best sailors and the best technology (in that order) tended to win, and often decisively. The 19 ^th century inventions revolutionized naval warfare beyond recognition but the 20th century saw an avalanche of new naval technology that has not ended. There was so much new stuff that it's instructive to look at which technologies had the biggest impact. Often, it's things that don't seem so important at first but later turn out to have been decisive items. The list below contains ten items that grew to become crucial technological developments for naval warfare in the 20 ^th century (and into the 21 ^st ).

1-Operations Research (OR). The analytical application of mathematical solutions for many problems first appeared in the 1930s, and became crucial during World War II (and beyond) for developing more effective ways to use new technology. This became particularly useful in anti-submarine warfare but eventually led to improvements in just about all aspects of naval warfare. This increased the capabilities of the navy, playing a major role in making the USN the most powerful navy in history. OR continues to perform largely unheralded miracles by identifying elusive solutions and detecting well concealed flaws.

2-Gyroscopic compass. This early 20th century invention had a far reaching impact on naval warfare. Initially it made navigation more efficient for all ships. But the gyroscope technology led to vast improvements in fire control and, eventually, inertial navigation systems. This made possible all manner of anti-ship missiles. So, if you're wondering why all the guns went away, this is the main reason why. Even the development of satellite navigation didn’t completely replace gyroscopic navigation. Gyroscopic systems can’t be jammed and still serve as a less accurate backup system for GPS guided weapons.

3-Gas Turbines. The most obvious use of gas turbines is in jet engine equipped carrier aircraft. But ten years after jet aircraft began to replace piston powered warplanes on aircraft, the first ships (hydrofoils) began to use gas turbine power plants. But by the late 1960s, the huge TF39 jet engine developed for the C-5 aircraft was being reworked as a maritime power plant (the LM2500). Over three decades later this gas turbine ship engine is common not only in merchant ships but warships as well. The LM2500 is efficient, reliable, and capable of providing quick bursts of speed not possible with older steam or diesel power plants. Just as the revolutionary small tube steam plants went unnoticed early in the 20th century, the LM2500 also dramatically changed what a warship could expect from its power plant.

4-Battery technology. In the latter third of the 20th century battery technology made major strides, and this heavily influenced the design of naval weapons and equipment. Weapons like missiles, in particular, became smaller, more reliable, and deadlier because of smaller, more powerful, and longer lasting batteries. Try and run today's fleet with 1960s, era battery technology and you'll find that you can't. A major aspect of this was the use of lithium based batteries and the search continues for even more efficient (and safer) battery materials.

5-Servron. Developed out of necessity during World War II because of a lack of sufficient forward bases in the vast Pacific, the service squadrons became a permanent fixture in the U.S. Navy. Ships now normally stay at sea for up to six months at a time, being resupplied at sea by a Servron. New technologies were developed to support the effective use of the seagoing supply service. Few other navies have been able to match this capability, mainly because of the expense of the Servron ships and the training required to do at sea replenishment. What made Western naval experts pay attention to the Chinese Navy expansion was the appearance of Servron type ships in the later 1990s. That trend has accelerated.

6-Merchant ship automation. Throughout the 20th century merchant ships have become less labor intensive. This has been due largely to market pressures. But warships have been resistant to this trend, largely because of tradition, the availability of many sailors, and damage control concerns. Lower manning will become more of a factor in the 21st century but the trend is a 20th century one.

7-Oceanography. Navies have always taken the lead in charting the details of coastal areas, where ships operate most frequently and are in most danger from uncharted objects. But the 20th century saw an enormous growth in the study of the high seas and what lay beneath. Much of this was in support of submarine operations and anti-submarine warfare. The greater understanding of the oceans has made naval operations more effective in many ways that often go unnoticed but never unappreciated. By the end of the 20^th century cheap, robotic, survey devices appeared, revolutionizing oceanography by providing more data and in a timelier manner.

8-Weather forecasting. For centuries unpredictable weather was the greatest danger to fleets at sea. Dramatic improvements in weather forecasting (especially weather satellites) have greatly reduced the risk of weather related damage for fleets and made operations more effective.

9-Personnel screening. As warships have become more complex, so have the number and complexity of the jobs sailors have to do. The ancient practice of signing any warm body and later deciding who was trainable for complex tasks crumpled under the pressure to get the right sailor for the right job before you sent people aboard a ship full of complex and expensive gear. As the navy became more of a high tech enterprise the personnel selection routines borrowed heavily from those developed in the commercial sector to solve similar problems. Without this shift in personnel policies the modern U.S. Navy would not be possible.

10-Scuba equipment. This was a 19th century development that was perfected in the 1930s, and was quickly adapted for naval warfare. Scuba equipped commandos often proved essential for successful amphibious operations. The downside of scuba equipment is that it provided underwater commandos with a practical weapon to use against warships.

The 21st century is just getting started and much unknown technology has yet to be invented. Many of the key 20th century warship technologies were unknown before World War I (1914-18). But we can already see some new stuff which is leading revolutionary changes in how navies will operate this century. Here are some of the more obvious ones.

Unmanned vehicles. Unlike aircraft, which were a new vehicle, UAVs (Unmanned Aerial Vehicles), UUVs (Unmanned Underwater Vehicles), and USVs (Unmanned Surface Vehicles) are radically new technologies. There are already examples of all three in service. There will be more and they will change everything by incorporating more powerful AI (artificial intelligence) and new weapons. That said, UUVs were first developed in the 19th century (the modern torpedo) and 20th (guided missiles are UAVs). But these two weapons were not flexible enough to change as many aspects of naval warfare as unmanned vehicles will be doing.

Super Sensors. Sonar (using sound to detect objects underwater) appeared during World War I (1914-18), while radar (using radio signals to detect objects in the air) was developed during the 1930s and widely used during World War II (1939-45). Widely recognized as the first electronic sensors (although the earliest sonars were all-acoustic), their 21st century descendants are much more capable. More powerful computers and transmitting technology has since produced several generations of cheaper, more reliable, and more powerful sensors. This is continuing and the power of new sensors will make it much more difficult to hide. Stealth is still important for spoiling the aim of long range guided weapons. But the super sensors make it much more difficult to achieve surprise by coming out of nowhere.

AI (Artificial Intelligence). AI is a 20th century development that is expected to become pervasive in the 21st. Current examples includes AI assistants built into a lot of software. For aircraft designers a long-sought goal was an AI assistant for pilots. Thus the computer's memory contains the experiences of numerous more experienced pilots as well as instant information on the rapidly changing situation. You can ask your electronic assistant what the options are and which one has the best chance of success. The pilot can then make decisions more quickly and accurately. When enemy aircraft are sighted the electronic assistant can suggest which of the many maneuvers available are likely to work. If the aircraft is damaged the electronic co-pilot can rapidly report what the new options are. One becomes quite fond of computers once they have saved your bacon a few times. Many of these capabilities are being installed piecemeal, as part of electronic countermeasures or radar systems. And, bit-by-bit, these "thinking systems" are being merged, producing an electronic co-pilot. Systems that completely replace pilots are in development as well. This is not radical but part of a trend. By the early 21^st century many commercial and military aircraft were more effective because they used so much AI. The same applies to ground vehicles.

All-Electric ships. Coal powered ships appeared in the 19th century, oil powered ones came early in the 20th, along with nuclear power (for a few) later. But the big revolution now is maximizing the amount of electrical power a ship can generate. That means an all-electric ship (where the engines produce just electricity and all ship equipment is electric powered). Such a ship makes possible more powerful sensors and electrically powered weapons (like lasers and rail guns). An all-electric ship also means more efficient use of power and lower fuel costs. There's no mystery in this technology, as commercial ships began using it in the 1980s. But for warships this will be a 21st century innovation.

Stealth. No matter how much better sensor technology becomes, there is always an advantage to having ships that are a bit harder to detect. In the last few decades stealth technology has developed faster than sensor capabilities. The big limitation with stealth capabilities is that they tend to get very expensive. But if you can afford it, you get an edge in combat.

Composites. Materials science went on a roll in the late 20th century, and more new, non-metallic materials able to replace steel and other metals are in the works. Composites began showing up in warships in the last few decades but as the use of these materials spreads to all parts of a vessel it will increase protection, fuel efficiency, and stealth.

Networking. This is already underway but is becoming faster, more reliable, and including more distant ships and shore stations. This kind of communications can give the side with faster and more completely networked forces a major edge.

Space Based Services. In the late 20th century navies began using space satellites for weather forecasting, communications, and reconnaissance. It was good, and the sailors want more, a lot more. To get it your space satellites will have to play defense against efforts to shoot them down. The U.S. Navy is seeking to equip its ballistic missile subs with warheads containing mini-sats to replace those shot down. American warships already have missile systems that can knock down low orbit recon satellites.

Nanotech. These ultra-tiny carbon structures are revolutionizing everything from batteries to computers and just about every aspect of warship construction and operation. Nanotech might still turn out to be perpetually just around the corner but so far it is a strong contender as the source of big changes.

Laser weapons. These would seem ideal for warships, especially those with all-electric drive. While showing much promise, laser weapons may also perpetually be just around the corner. That's where they've been for several decades now.

Anti-Ship Ballistic Missiles. This concept existed (in theory) since the late 20^th century. Since 2005 China has had an anti-ship ballistic missile, the DF-21D, in development. As far as anyone knows, or will admit, the complete system has not been tested. But components have and Western experts agree it is now mainly a matter “integrating” the many different techs into a workable weapon that would, in theory, be an ideal way of attacking American carriers. It's an expensive way to hit a carrier, since each of these missiles costs over $20 million. But if you have to get it done that's a reasonable price. In the future the price will come down a bit and anti-missile systems available to warships will be better at dealing with them. Guided warheads could also be launched from space satellites. You can see where this is going and there will be a lot more of it this century.

It has also been noted that China openly boasts (in unclassified military publications) that the most effective way to overcome the American military advantage is by obtaining (stealing if need be) American tech, mastering it and improving on it.