Meet the U.S. Navy's new Doomsday submarine

Kyle Mizokami, Popular Mechanics
14 March 2016
The Congressional Research Service has a report on the new class of nuclear ballistic missile submarines, telling us a little more about these Navy vessels currently under development, which will carry the nuclear weapons of tomorrow.
Nuclear missile submarines, which spend months at a time submerged in classified patrol areas, are considered the most "survivable" of the so-called nuclear triad (land-, sea-, and air-launched nuclear weapons). The downside is that they are less accurate than land-based missiles and tend to be assigned retaliatory missions against "countervalue" targets—civilian targets such as cities, factories, oil refineries, and transportation infrastructure. The United States Navy still maintains 14 Ohio-class
nuclear missile submarines. Each "boomer" carries 20 Trident D-5 missiles, and each Trident packs up to twelve nuclear warheads, each six times more powerful than the bomb dropped on Hiroshima.
The next-generation sub—known as SSBN(X)—will enter service in 2021 with a host of new improvements. One item high on the Navy's wish list is a nuclear fuel supply that will last the lifetime of the submarine, allowing the Navy to avoid a costly and time-consuming refueling job two decades into the ship's tenure. The Navy also wants an electric drive propulsion system, which will be much quieter than current mechanical drive systems.
SSBN(X) will be slightly larger than the existing submarines, displacing 20,815 tons, compared to 18,750 tons for the Ohio subs. It will have a beam of 43 feet, making it a foot wider than the Ohio class and nine feet wider than the Virginia class attack submarines.
The new submarines will carry fewer nuclear missiles than their predecessors. Each will have launch tubes for 16 Trident D-5 missiles, for a grand total of 192 tubes spread out between the dozen ships. While that may not sound like a lot, each Trident can carry up to ten nuclear warheads. So we're talking about 1,920 nuclear warheads overall.
All of this will cost money—a lot of money. The total cost of the SSBN(X) program is expected to be $95.8 billion, including $11.8 billion in research and development costs and $84 billion for the submarines themselves. The first sub is expected to cost a whopping $14.5 billion, and $4.9 billion a pop for the rest. Consider that most Pentagon programs inevitably encounter cost overruns of approximately 20 percent and the true cost of this program boggles the mind.
Is it all of this money just to build a dozen submarines worth it? That's a very good question. It's been 30 years since the Ohio class was justified, and in that time the Cold War has since ended and nuclear arsenals around the world have undergone sweeping cuts. Still, the threat hasn't gone away completely: Putin's Russia has grown increasingly aggressive and has made modernizing Russia's nuclear submarine force a top priority.