Question: Which Built by has a Name of Northern Jaeger?
SQL: SELECT "Built by" FROM "2-15230458-1" WHERE "Name" = 'Northern Jaeger';

Question: How many Horsepowers have a Year smaller than 1974, and a Tonnage of 4437?
SQL: SELECT SUM("Horsepowers") FROM "2-15230458-1" WHERE "Year" < 1974.0 AND "Tonnage" = 4437.0;