cg9 banner


Shipbuilding 101


For the Coast Guard and its sister sea-services, the art of naval ship design and construction is crucial to mission success. Working closely with the American shipbuilding industrial base, as well as completing due diligence research, world-wide, into the capabilities of comparable vessels, the Coast Guard’s naval engineers and acquisition professionals help to develop surface platforms that meet the needs of the service, into the 21st century. The process of building an advanced ship, such as the National Security Cutter, is one that marries time-honored traditions and lessons learned from centuries of naval architecture, with state-of-the-market technologies that deliver the mission capabilities demanded of today’s complex operational environment.


Unlike aircraft or automotive manufacturing, where many more or less identical platforms are produced, ships typically are built in series (that is, one at a time). There is little or no prototyping in shipbuilding, beyond some laboratory work with advanced hull forms or other structures. A new aircraft design may have been built and flown many times before actual first article production begins. A prototype aircraft rarely is delivered to the customer as an operational asset. In shipbuilding, the first-in-class (a series built to the same basic design) often serves as the class prototype, as well as the first article delivered for operational service.


A first-in-class ship is constructed directly from designs or drawings that are maturing as building continues. Because of the complexity of these processes, first-of-class ships may take between three and six years to complete—from contract award to delivery. Lessons are being learned and applied as the ship is being built and with each subsequent hull constructed in the class. There may be significant hull, mechanical and electrical design or architectural variations from one number to the next within a class of ships.

Assembling in Units

Today’s larger shipyards are equipped to erect ships in individual assemblies, which contain decks stacked within huge sections of the ship’s outer hull. The assemblies are built upside down (because welding with gravity is more efficient than working against it) at large assembly halls, away from the waterfront. There, the assemblies are outfitted with piping, ventilation ducts and other sub-assemblies and equipment. In certain sections of the ship, these assemblies are stacked together in what are called grand blocks. The completed assemblies and grand blocks are then brought down to the ship’s keel (laid at a site along the waterfront) where the ship is assembled, or erected, and welded together.


Simplified, the sequence of events consists of:

  • A mission need leads to the development of operational requirements for a new ship.
  • Requirements are used to inform the ship project’s concept and design development phase, and a contract for the project is awarded to industry.
  • Once the design is matured to a certain degree in drawings or models, the shipbuilder lays the keel and begins construction.
  • As construction progresses, the government selects a ship’s name and a sponsor (usually a dignitary, or traditionally the eldest female descendent of the person for whom the ship is named).
  • In a ceremony, the sponsor christens the ship, at which time it officially receives its name.
  • When construction is almost complete, the ship undergoes a series of sea trials, which are comprehensive government and industry inspections, tests and evaluations of the condition and functionality of ship as measured against the project’s requirements.
  • When trials are concluded and the ship is judged to be satisfactory, the shipbuilder delivers it to the government.
  • Delivery marks the date when the ship has been found acceptable for service and becomes government property.
  • Commissioning follows a period many months preparation, training, further inspection and testing. Commissioned ships are considered operational assets, having earned the title U.S. Coast Guard Cutter.


Acceptance Trials (AT) is a rigorous test process and material inspection carried out underway by the government (often represented by the U.S. Navy’s Board of Inspection and Survey (INSURV)) to determine that ships constructed in private industrial shipyards are suitable for delivery.

Builders Trials (BT) is a contractor-conducted event to inspect, test and evaluate a ship's performance underway. One important purpose of BT is to assure the builder and the government that the ship is, or will be, ready for Acceptance Trials (AT). BT typically includes a comprehensive test of all ship's equipment and is similar in scope to AT.

Christening is a long-standing naval tradition including a ceremony wherein the ship’s sponsor (usually a woman) breaks a bottle of champagne across the bow and grants the ship its name.

Commissioning is an elaborate ceremony that officially places the ship in service and adds the prefix U.S. Coast Guard Cutter to her name. Prior to commissioning, it is inappropriate to use the U.S. Coast Guard Cutter title before the ship’s name as the vessel is not yet officially in government service. Although commissioning places the ship in service, much work usually remains to be done by the crew to bring the ship to its full operational capability.

Delivery is the date when all systems have been tested and discrepancies corrected to the government's satisfaction, and a representative from the Coast Guard officially accepts custody of the ship from the shipbuilder. The ship’s pre-commissioning crew moves aboard to perform training, qualification and certification of equipment activities.

Dock Trials is a broad term referring to events conducted at the shipyard to determine the ability of the ship, from a material standpoint, to conduct sea trials safely.

Laying the Keel represents the beginning of a ship's construction. The keel is the key structural member stretching the length of the ship.

Launch is the date when a ship is first placed in the water; the ship must be watertight, but construction need not be complete for launch to take place.

Light-Off occurs as various major components of the ship are completed, energized and tested. Light-off events include electronic systems light-off (which may include the ship’s Command, Control Communications, Computers, Intelligence, Surveillance and Reconnaissance (C4ISR) equipment), electrical generator light-off, combat systems light-off, and main engine light-off. These events are significant steps in the construction process.

Machinery Trials (MT) (often synonymous with, or occurring as part of dock trials) are inspections, tests and evaluations specific to the ship's machinery, including its main propulsion system.

Pre-Commissioning (PRECOM) Crews are designated to take charge of the ship following delivery. The PRECOM crew's task is to prepare the vessel and its mission systems for full operational capability in Coast Guard service.

Post-Shakedown Availability is an industrial activity availability following delivery and is used to correct deficiencies found during the shakedown period, or to accomplish other authorized improvements to the ship.

Sail Away is the date of the ship's final departure from the construction yard for its homeport or commissioning site. This date signifies the end of the new construction and the beginning of final preparations for operational service.

Sea Trials is a general term referring to are a series of rigorous, underway tests to determine that the ship's hull, mechanical & electrical and other systems function as required. Trials typically have three phases: dock trials (also machinery trials, conducted while the ship is still tied to the pier), builders trials (done at sea by the contractors who built the ship), and acceptance trials (conducted at sea and ashore by government personnel). Discrepancies noted during trials must be corrected prior to delivery.

Ship Naming traditionally occurs before the ship is christened, while construction is in progress. During the naming phase the ship's sponsor (who will christen the ship) also is selected. In the case of ships named for individuals, an effort is made to identify the eldest living direct female descendant of that individual to perform the role of ship's sponsor.

Stepping the Mast is an ancient practice where coins are placed under or near the ship’s mast. Traditionally, the value of the coins usually adds up to the ship’s hull number.