LONDON—Shipping operators and investors are pouring billions of dollars into building new oceangoing tankers to transport diesel, gasoline and aviation fuel—scrambling to keep up with North America’s energy boom. The shipbuilding frenzy is another knock-on effect of an energy revolution unfolding in the U.S. and Canada, where new drilling and extraction technology has unlocked vast new reservoirs of crude oil and natural gas. The U.S. still imports part of its crude-oil needs, but the newly tapped American oil has lowered costs for refiners. That is allowing them to better compete with their overseas rivals, ratcheting up exports and fueling demand for new tankers. New York-based Scorpio Tankers Inc. STNG -0.84% Scorpio Tankers Inc. U.S.: NYSE $ 11.78 -0.10 -0.84% Oct. 30, 2013 4:02 pm Volume (Delayed 15m) : 1.07M U.S.: NYSE $ 11.78 0.00 0.00% Oct. 30, 2013 4:39 pm Volume (Delayed 15m): 31,234 P/E Ratio N/A Market Cap […]