What had clearly been learned in the 1969 voyage were several basic Arctic icebreaking truths:

• A large mass moving at decent speed (our “model”) could break very tough multi-year ice and ridges, but it would need real backing power to prevent getting stuck, an absolute “must” if un-escorted tankers were to succeed.
• Maneuverability in ice is very difficult for a “parallel body” merchant ship shape even with bow bulges.
• Geared steam turbine machinery with new propellers and shafts could withstand the severe shocks that broken ice floes going through the propellers often caused.
• In near “open” water conditions, growlers and bergy bits were able to cause major structural damage in nonreinforced parts of the ship’s hull.
• Success of icebreaking tankers would be very much in the hands of a ship’s crew, even with reconnaissance by aircraft and side-looking radar, to find preferable routes though the ice. Most important was the conclusion supported by all who participated in the Manhattan voyage was that it is technically and economically feasible to use non-escorted large icebreaking merchant ships for the routes explored, and most likely also for the Northern Sea Route.