The Mules (Mulas in Spanish) are one of the vital and essential elements for a safe transit. The locomotives of the Panama Canal allow transoceanic vessels that use the locks in their transit from the Atlantic to the Pacific to remain in the center of the structures and avoid the impact against the walls. The 'mules', as they are called in local slang to these immense locomotives, pull the ships that smoothly save the different locks of the channel. Each 'mule' weighs 50 tons and operates with two 290 horsepower units, which gives it a towing capacity of 311.8 kN of 4.8 kilometers per hour and 178.2 kN at 8 kilometers per hour.