Ordered in 2002 and built by Schelde Shipbuilding of the Royal Schelde Company, Vlissingen in the Netherlands, she was launched in February 2007.
She has a displacement of 15,000 tonnes and is 176.35m long with a beam of 29m and 6m draft.
Powered by four Stork Wartsila model 12SW28 diesel-electric engines she can make 19 knots and at this speed has a range of 6000 nautical miles.
She is designed to undertake amphibious tasks include the ability to embark, transport and disembark a battalion of troops including all their combat and logistical support vehicles and equipment. Johan de Witt can land troops and equipment off-shore without any harbour or similar facility, this is done by lowering the stern of the ship by up to 4m, this enables seawater to fill the dock and landing craft can then leave the ship.
Together with the ships crew, troop accommodation and storage areas she also has extensive medical facilities including operating theatres and treatment rooms.
Main armament consists of two Goalkeeper CIWS 30mm guns providing a maximum firing rate of 4200 rounds / minute up to a range of 1500m. This is supplemented by up to six .50 calibre machine guns. To support the Goalkeeper CIWS, a Thales Nederland IRSCAN infrared search and track system is fitted, this can detect and track targets to a maximum range of 20km.
The rear flight deck can accommodate two helicopters simultaneously and the main hanger can hold either 6 x NH-90 or 4 x Chinook helicopters.
As well as military operations she can be usefully deployed in crisis-response operations, natural disasters and evacuations.