Here we see one ship just heading out of the locks from the Atlantic into Lake Gatun ('Athens Star' - right) and on to the Miraflores Locks to get to the Pacific; and one coming from the lake (distant on the left) heading for the Atlantic. These are both 'PanaMax' ships, being as wide as the Locks will allow. The locks are 110' wide, so a PanaMax ship cannot be over 106' abeam, allowing only 24" on each side between the hull and the Locks. The ships are guided through the locks by the electric 'Mules', small railway-like engines that run along the track seen parallel to the locks on each side. They keep the ship from hitting the sides, and stop it; the ships move forward on their own steam.