The U.S. Navy is continuing the build-out of two of its classes of support ships launched in the last decade to support naval operations. The San Diego-based shipbuilder General Dynamics NASSCO is receiving an additional $1.4 billion in U.S. Navy contract modifications for the construction of a sixth Expeditionary Sea Base ship and two additional John Lewis-class fleet oilers. This award comes in addition to $600 million already received to procure long-lead time materials for the same ships.