CREATE TABLE table_53896 ("Name" TEXT, "Original name" TEXT, "Commissioned" TEXT, "Final decommission" TEXT, "Fate" TEXT)

When was the ship that had a fate of 'converted to laker, 1961; still in service' commissioned?
SELECT "Commissioned" FROM table_53896 WHERE "Fate" = 'converted to laker, 1961; still in service'
SELECT "Commissioned" FROM "table_53896" WHERE "Fate" = 'converted to laker, 1961; still in service'