Over a third of American SSN subs are out of action while undergoing regular maintenance, or waiting their turn to receive it and be fully capable of operating at sea. Virginia class SSNs have a service life of 33 years. During this time the subs will carry out 15 deployments, each of them six-to seven months long. There are also training deployments and time spent moving to an overseas base or a maintenance facility. That means each Virginia will spend about 30 percent of its time at sea during its 33-year service life. Time at sea includes deployments, short training trips or longer periods spent moving to a new base.
The problems with the Virginias are not unique. Other nations with submarine fleets and limited shipyard capacity have similar problems. For example, back in 2018, the German navy began the year with none of six Type 212 diesel-electric submarines available for service. One damaged its steering mechanism in December 2017 when U-35 struck a rock off Norway. The other five 212s are either undergoing repairs or maintenance or waiting for a dry dock to become available for essential work. There were other problems, similar to those that have kept many German warplanes and armored vehicles out of action since the 1990s. That was a lack of spare parts. While Germany had the fourth largest defense budget in the world, that budget was already allocated and efforts to obtain more money for spare parts failed. German defense spending declined by nearly 25 percent between 1990 and 2005. At that point the budget grew until it was back to 1990s levels in 2007. Growth accelerated after 2014, when Russia seized Crimea and other Ukrainian territory. The additional German spending went to improve and expand the ground forces. An aggressive Russia was not going to launch an amphibious attack on anyone.
In 2022 Russia invaded Ukraine, which shared a border with Germany’s eastern neighbor Poland. At that point a large portion of the defense budget went towards supplying Ukraine with weapons and preparing the army to assist Poland if the Russians reached the Polish border kept going. That was unlikely. Unlike Ukraine, Poland was a member of NATO, and the NATO rules specify that if anyone attacks a NATO member, all 31 NATO nations respond to fight the aggressor. Ukraine was not a NATO member and wanted to join. That was one reason Russia invaded Ukraine.
German defense spending was sharply cut in the 1990s. This was the peace dividend; i.e., the expected savings from the demise of the Soviet Union and its enormous military, including the second largest fleet on the planet. The Type 212s entered service during this period and the failure to buy sufficient spare parts soon led to subs being sidelined until the spares could be manufactured. In some cases, spares were obtained by taking components from subs sidelined for something else so that two subs would not be out of action. But this was more expensive, and the situation just kept getting worse until there were no subs available for service and that situation was not going to improve until the navy received a lot more money for spares and maintenance.
Germany believed their U-Boats would provide a major threat to increasingly aggressive Russian warships in the Baltic and North Sea. That never happened because the Russian invasion of Ukraine triggered massive economic sanctions that were enforced by blocking Russian shipping in the Baltic Sea. This forced Russia to move its seaborne trade to northern ports adjacent to Norway and the bases for the Russian Northern Fleet. NATO surface warships enforced the sanctions against Russian trade. This was always the NATO plan and submarines were not needed.
The German submarines exist to support German submarine exports. That was always the intent, even though the 212s were developed simply to replace the Cold War era Type 209s and keep a prosperous export business going. In late 2005 Germany commissioned its first Type 212 submarine, U-31. This was quickly followed by U-32 and two more in 2006 and 2007. Two more entered service in 2015 and 2016. Another two were planned but never ordered. Italy also has four Type 212s. Germany is one of four nations that build submarines for export and is the largest producer.
Type 212s are special boats as they were among the first to use fuel cells (for AIP, or Air Independent Propulsion) which enable them to quietly operate underwater for weeks at a time. They still have diesel propulsion, but this is only used for surface travel. The 212's are also very quiet, quieter than most nuclear boats in service. This makes them an even match for a current nuclear boat equipped with better sensors. The 1,450 ton 212's are much smaller than nuclear boats. For example, the 6,200-ton American Virginias are 115 meters (377 feet) long, twice as long as the German 212s. The nuclear boats are used for a lot more than hunting ships and other subs, while the 212's are mainly attack boats, and well designed and equipped for it. While Germany is an American ally, their development of fuel cell technology for subs, and use of these boats in their own navy, made this technology mature and eventually available to many more nations. These 212 boats are expensive, about half a billion dollars or more each. That's less than a third the cost of a nuclear boats. The 212's are also highly automated, requiring a crew of only 27. But with six torpedo tubes, and a dozen torpedoes, which can include anti-ship missiles launched from the tubes, as well as mines, the 212s could be, in the wrong hands, a major threat to the U.S. fleet. Cheaper to buy, cheaper to run and you don't need as many skilled sailors for the crew. These non-nuclear subs are very lethal. American admirals always paid attention to who the Germans export these boats to. Most of the exports are the less expensive Type 2014, which are 212s without a lot of highly classified technology.