USS Gerald R. Ford Finds Center of Gravity With Rare Inclining Test

April 22, 2020

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USS Gerald R. Ford (CVN 78) pulled away from the pier for three hours into the Elizabeth River to conduct a rare weighted inclining experiment, April 16.

The purpose of the inclining experiment is to calculate the ship’s weight and center of gravity. Information from the test is also used to determine the ship’s stability in a variety of design loading conditions.

“This testing of the ship’s weight will become the baseline for which it is measured for her life of service,” said A.J. Bierbauer, the deputy chief engineer for Newport News Shipbuilding. “As the ship gets older, there will be alterations made to her, and as is the case with many ships, they tend to get heavier through the years. This test will help establish the baseline weight for the life of the ship.”

While many smaller naval ships such as cruisers and destroyers incur frequent inclining tests throughout their lifespan, Bierbauer said that carriers typically only see a total of three inclining experiments in their lifetime, although other types of stability tests can be done when necessary.

“On an aircraft carrier, you’ll generally get the initial incline test during the new construction phase,” said Bierbauer. “The next inclining will be after the ship’s Refueling and Complex Overhaul phase, and then the last inclining the ship will get is when she’s inactivated, to determine that once the ship is decommissioned, it has adequate stability to be towed to wherever the dismantling process will take place.”

In preparation for the inclining experiment, contractors from Huntington Ingalls Industries Newport News Shipbuilding Division (HII NNS) and Naval Sea Systems Command (NAVSEA) conducted a load survey over several weeks by identifying weight loads and checking tank levels in every space on the ship, to include storerooms, weapons magazines, list control tanks, and even jet propellant 5 (JP-5) tanks.

According to the ship’s Damage Control Assistant, Lt. Cmdr. Gregory Descovich, to ensure accuracy of weight measurements, no loading or offloading of stores, equipment, production materials, or other items occurred until inclining was completed. Additionally, once the inclining experiment began, personnel were directed to “remain stationary and shifting of liquids onboard was secured to further assure the accuracy of the results,” he stated in a notice to the crew.

The inclining experiment began once the ship was breasted away from the pier. HII NNS and NAVSEA personnel in Jon boats took baseline readings of the draft markers located on Ford’s bow, midships, and stern. A transporter then moved inclining weights, totaling approximately 140 tons, into various positions across Ford’s flight deck. Following weight movements, personnel measured and recorded each movement distance, and measured the ship’s inclination using precision inclinometers. A second round of draft readings were also recorded by personnel in the Jon boats. The final piece to the experiment was a sallying test.

“The end result data set from the incline test and the sally test will validate the damage control stability characteristics of the ship,” said Cmdr. Homer Hensy, Ford’s chief engineer. “This data will allow the Commanding Officer and the crew to stabilize the ship in the event of battle damage and allow Ford to maintain a stable deck to continue strike operations against our adversaries.”

The inclining experiment was a conglomerate effort by Naval Architects from HII NNS and NAVSEA and Ford crew members.

“The preparations by the crew and Huntington Ingalls Shipyard over the last few weeks was over 1,800 hours spent validating the liquid stores, parts and supplies in every space bow to stern,” Hensy continued. “This event is another successful example of the teamwork of the Ford crew and HII to continue to make Ford ready for unrestricted fleet operations in the future.”

Gerald R. Ford is a first-in-class aircraft carrier and the first new aircraft carrier designed in more than 40 years.

Source : US Navy