The size of a Panamax vessel is limited by the original Panama canal's lock chambers, which can accommodate ships with a beam of up to 32.31 m, a length overall of up to 294.13 m, and a draft of up to 12.04 m.[21] The Post-Panamax category has historically been used to describe ships with a moulded breadth over 32.31 m,[22] however the Panama Canal expansion project has caused some changes in terminology.