The Panama Canal Authority (ACP) plans to extend the capacity of and allow larger ships to the Canal by building a so-called third lane, consisting of a new set of locks parallel to the existing ones. The design ship is a so-called Post-Panamax 12000 TEU container carrier. In order to optimise the approach to and the manoeuvres within the locks, in 2007-2008 experimental research has been conducted at Flanders Hydraulics Research, Antwerp, Belgium on a 1/80 scale model of the approach lane, the lock and the design vessel. With the ship model moving along a guiding rail, lateral forces acting on the ship and movements of the vessel can be recorded during a selection of entrance and exit manoeuvres. During a number of tests, the effect of density exchange current was examined. The present article offers an overview of the test-setup with a discussion of a few interesting results of the test runs. INTRODUCTION The Third Set of Locks and the new approach lane the Panama Canal Authority (ACP) plans to build, will allow the acceptance of larger post-panamax size vessels and increase the throughput of the canal significantly. Triple lift type locks with rolling gates have been designed. Each new lock chamber will have a length varying between 427m and 488m, depending on the opening of the double inner gates. The width of each chamber will be 55m. The design ship is a so-called Post-Panamax 12000 TEU container carrier (length over all 366m, beam 48.8m, draft 15.2m; block coefficient 0.65).