page_title: Panamax
section_title: Ship dimensions
hierarchical_section_title: Panamax / Ship dimensions
caption_attribution_description: English: USS Missouri (BB-63) in the Miraflores Locks, Panama Canal, 13 October 1945, while en route from the Pacific to New York City to take part in Navy Day celebrations. Note the close fit of the ship in the locks. The beam of battleships of this era was determined by Panama Canal lock dimensions. Specifically, the locks are 110 feet wide, and the beam of the vessels are 108 feet and some inches, leaving about 8 inches of clearance, per side.
context_page_description: Panamax and New Panamax are terms for the size limits for ships travelling through the Panama Canal. The limits and requirements are published by the Panama Canal Authority in a publication titled "Vessel Requirements". These requirements also describe topics like exceptional dry seasonal limits, propulsion, communications, and detailed ship design.
  The allowable size is limited by the width and length of the available lock chambers, by the depth of water in the canal, and by the height of the Bridge of the Americas since that bridge's construction. These dimensions give clear parameters for ships destined to traverse the Panama Canal and have influenced the design of cargo ships, naval vessels, and passenger ships.
  Panamax specifications have been in effect since the opening of the canal in 1914. In 2009 the ACP published the New Panamax specification which came into effect when the canal's third set of locks, larger than the original two, opened on 26 June 2016. Ships that do not fall within the Panamax-sizes are called post-Panamax or super-Panamax.
context_section_description: Panamax is determined principally by the dimensions of the canal's original lock chambers, each of which is 110 ft (33.53 m) wide, 1,050 ft (320.04 m) long, and 41.2 ft (12.56 m) deep. The usable length of each lock chamber is 1,000 ft (304.8 m). The available water depth in the lock chambers varies, but the shallowest depth is at the south sill of the Pedro Miguel Locks and is 41.2 ft (12.56 m) at a Miraflores Lake level of 54 ft 6 in (16.61 m). The clearance under the Bridge of the Americas at Balboa is the limiting factor on a vessel's overall height for both Panamax and Neopanamax ships; the exact figure depends on the water level.
  The maximum dimensions allowed for a ship transiting the canal using the original locks and the new locks (New Panamax) are:
caption: USS Missouri, one of the Iowa-class battleships, makes a very tight fit as she passes through the Miraflores Locks of the Panama Canal in October 1945.
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