▁its ▁sib ling ▁the ▁S ag am ore ▁Bridge ▁were ▁constructed ▁beginning ▁in ▁ 1 9 3 3 ▁by ▁the ▁Public ▁Works ▁Administration ▁for ▁the ▁United ▁States ▁Army ▁Corps ▁of ▁Engine ers , ▁which ▁oper ates ▁both ▁the ▁brid ges ▁and ▁the ▁canal . ▁Each ▁bridge ▁car ries ▁four ▁lan es ▁of ▁traffic ▁over ▁a ▁ 6 1 6 - foot ▁( 1 8 8 ▁m ) ▁main ▁span , ▁with ▁a ▁ 1 3 5 - foot ▁( 4 1 ▁m ) ▁ship ▁clear ance . ▁Const ruction ▁ended ▁in ▁early ▁ 1 9 3 5 ▁and ▁the ▁bridge ▁opened ▁on ▁June ▁ 2 2 , ▁ 1 9 3 5 . ▁The ▁approaches ▁to ▁the ▁main ▁span ▁of ▁the ▁Bour ne ▁Bridge ▁are ▁consider ably ▁longer ▁than ▁those ▁of ▁the ▁S ag am ore ▁Bridge ▁due ▁to ▁the ▁top ography ▁of ▁the ▁land . ▁The ▁bridge ▁rep laces ▁an ▁earlier ▁ 1 9 1 1 ▁draw bridge , ▁and ▁the ▁original ▁draw bridge ' s ▁approaches ▁are ▁still ▁accessible . ▁The ▁current ▁structure ▁was ▁built ▁to ▁accommod ate ▁the ▁w iden ing ▁of ▁the ▁canal . ▁ ▁The ▁bridge ▁comm ences ▁at ▁a ▁major ▁traffic ▁circle ▁on ▁the ▁Cape ▁C od ▁end . ▁On ▁the ▁main land ▁side , ▁New ▁York ▁Central ▁T ug bo at ▁ 1 6 ▁sat ▁on ▁dry ▁land ▁at ▁the ▁approach ▁to ▁the ▁bridge ▁from ▁the ▁rot ary ▁from ▁ 1 9 8 2 ▁to ▁ 2 0 0 6 , ▁serving ▁as ▁a ▁local ▁att