The US yard said the deal has been struck with Philadelphia's development corporation PIDC Regional Center for a five-year facility at interest of 2.75%.
It is secured by a lien on the company's interests in hulls 021 to 024, which are the four product tankers to be included in the AKPS-Crowley joint venture.
PIDC offers loans to job-creating projects.
The yard has already secured a loan of $120m from Caterpillar Financial Services Corporation to build the ships, and a commitment from other lenders for $325m of post-delivery financing.
