April 18, 2024: The U.S. Navy’s Columbia SSBN (ballistic missile submarine) program is an effort to design and build a new class of twelve SSBNs to replace the Navy’s current force of 14 aging Ohio-class SSBNs. Since 2013, the Navy has consistently identified the Columbia-class program as its top priority program. Because of that the Navy was able to order its first Columbia-class boat in 2021. The Navy is now trying to obtain enough money to order and build the last nine of the twelve total Columbias. The first Columbia will cost $15.2 billion while the remaining eleven will cost about $9 billion each. The total cost of all twelve SSBNs is expected to be $347 billion when you include total lifecycle costs of each boat. The first ship of a class is always more expensive because it includes the research and development money spent on developing the entire class.

The first three Columbias have been ordered and the first one is expected to enter service in 2031 with all twelve in service by 2042. These SSBNs will serve until 2085 and will not require a mid-life refueling of its nuclear reactor. There will be a mid-life refurbishment for each SSBN, but it will cost less and be completed sooner because refueling is not required.

Each Columbia is expected to serve for 42 years. Once in service each SSBN will carry out 124 deployments, each about three months long followed by a month in port for maintenance and allow the crew some time with their families. Most of the 150 personnel on an SSBN are married. The Columbias will also spend several long periods receiving extensive maintenance and refurbishment. While there will be twelve Columbias, normally only a few will be at sea on deterrent patrols. If there is an international crisis more Columbias can be sent out.

Each Columbia displaces 20,000 tons and is 171 meters long with a beam of 13 meters. Armament consists of sixteen Trident D5 ballistic missiles and an as yet undefined number or torpedo tubes for the Mk 48 wire-guided torpedoes on board for dealing with threats from other ships or submarines.

The Columbias use a pulse jet propulsion system instead of propellers, and a quieter engine to power the propulsion system. A new sensor system provides the crew with a better perception of what other ships or submarines are in the area so that the SSBN can avoid them. For an SSBN survival is all about stealth and not being easy to detect or follow. Modern SSBNs are so quiet that they risk collision with other SSBNs. There was such a glancing collision between a French and a British SSBN. There was little damage to either SSBN, but it was an example of how quiet and elusive modern SSBNs have become. There are still actual or potential problems with the Columbias that may prevent them from entering service on time in 2031 with its first patrol. Some of the older Ohio class SSBNs can be retained in service for a while until the first Columbias are ready.