The RFP, released June 30 with proposals due July 14, covers up to seven vessels under an IDIQ contract, replacing 65-foot light icebreaking tugs commissioned between 1961 and 1967. The 69-foot cutters, combining light icebreaking and aids-to-navigation duties, must break 12 inches of level ice continuously at 3 knots and operate for three days without resupply; Congress has allocated $816 million for the light and medium icebreaker procurement.