The Tulsa Fire Department is replacing five of its most expensive ladder trucks after years of malfunctions and mounting maintenance costs rendered the $1.4 million assets unusable for firefighting operations. The E-One truck and Bronto Skylift ladder combos, purchased under the previous Fire Department administration, were a major expense. Three of the fire engines were purchased just five years ago for $1.4 million each. Two more were purchased years earlier for about the same price but already have been removed from service. The most recent malfunction came early Thursday when one of the Bronto Skylift ladders malfunctioned halfway up during a chemical fire at the Tulsa Port of Catoosa, Fire Capt. Stan May said.