Shipowner Seaspan Corporation said it has entered into purchase orders to build five 12,200 TEU containerships. Upon completion and delivery, all five vessels will commence long-term charters with a global liner company and are subject to vessel purchase obligations at the conclusion of the charters.Seaspan, a wholly owned subsidiary of Atlas Corp, said the newbuild vessels are to be financed from additional borrowings as well as cash on hand. This transaction is expected to add approximately $910 million of contracted cash flows over the charter period.Bing Chen, Chairman, President and Chief Executive Officer of Seaspan, commented…