CREATE TABLE table_30292 ("Vessel" TEXT, "Built" FLOAT, "Max Speed" TEXT, "Length" TEXT, "Breadth" TEXT, "Flag" TEXT, "Propulsion" TEXT)

What is the length when the propulsion is controllable pitch propeller?
SELECT "Length" FROM table_30292 WHERE "Propulsion" = 'Controllable pitch propeller'
SELECT "Length" FROM "table_30292" WHERE "Propulsion" = 'Controllable pitch propeller'