Aerial view of the Brazilian Navy’s 500t Macaé-class patrol vessel. Credit: INACE.
Arsenal de Marinha do Rio de Janeiro (AMRJ) is constructing the Macaé-class patrol vessels. Credit: INACE.
Bofors 40 Mk4 naval gun is the primary weapon of the Macaé-class patrol vessel. Credit: BAE Systems.

Macaé-class is a series of offshore patrol vessels (OPVs) being constructed for the Brazilian Navy. The vessels will patrol Brazilian Jurisdictional Waters (AJB).

The primary missions of the vessels include maritime patrol, naval inspection, pollution control and protection of oil and gas infrastructure. The fleet will ensure the safety of the national maritime traffic and protection of the ‘Blue Amazon’ area on the Brazilian coast.

The Macaé-class vessels are being built under a five-ship acquisition programme launched by the government of Brazil in 2006.

The keel for the first ship in the class Macaé (P70) was laid in November 2006 and the ship was delivered to the Brazilian Navy in December 2012. The second vessel Macau (P71) was commissioned in November 2010. The keel for the third ship Maracanã (P72) was laid in November 2009.

Indústria Naval do Ceará (INACE) built the first two patrol vessels. Arsenal de Marinha do Rio de Janeiro (AMRJ) is constructing the remaining ships.

Macaé-class patrol vessel design and features

The Macaé-class patrolling vessels are based on the French CMN Vigilante 400 CL54 platform. Its proven design incorporates a round bilge hull for high stability in rough seas. The hull is made of steel, while the superstructure of the OPV is built using aluminium. The modular design further enables the integration of subsystems for multiple applications.

The stern side of the ship is equipped with a dedicated A-frame davit to launch and recover two rigid-hull inflatable boats (RHIBs). The patrol vessel has a displacement of 500t and will be able to accommodate a crew of 49 members.

The OPV measures 55.2m-long and 8m-wide, while the depth and draft of the vessel are 4.6m and 2.3m respectively.

Macaé-class patrol vessel weapons

The Macaé-class patrol vessels are armed with a 40mm cannon and two 20mm guns. BAE Systems is responsible for manufacturing and delivering Bofors 40 Mk4 naval guns for the vessels.

The 40 Mk4 gun is the latest naval version of the successful Bofors 40mm gun. It weighs approximately 2t, which is 1.5t less than the previous model, making it more accessible to wider platforms.

The compact size and footprint of the gun enable its integration with the small vessels. The gun system offers 100 ready-to-fire rounds and retains a capability to switch between ammunition types, including programmable 40mm 3P all-target ammo. The firing of the remotely operated gun is managed by a computer-controlled burst pattern and a muzzle velocity radar.

The gun has a maximum rate of fire of 300 rounds a minute and can engage targets such as hostile ships, attack aircraft, anti-ship missiles and shore-based targets within the range of 12.5km.

Navigation and communication

The vessels feature an integrated bridge system equipped with Sperry Marine new-generation VisionMaster FT™ navigation technology. The VisionMaster solution is interfaced with onboard navigation systems for effective route planning and navigation.

Macaé-class patrol vessels are equipped with an electronic chart display and information system. Other navigations systems onboard the vessel include gyrocompass, echo-sounder, speed log, navigation radar, steering controls, steering gear, mission data recorder and other sensors and subsystems.

The pre-installed communication equipment on the OPV enables it to maintain communication with different platforms when offshore.

Macaé-class propulsion and performance

The patrol vessels are powered by two MTU Friedrichshafen 16V 4000 M90 diesel engines coupled to a pair of controllable pitch propellers. The ship’s propulsion also integrates two main generator sets and an emergency generator to power the on-board systems.

The vessels can reach up to of 21k speed and attain a range of more than 4,600km at 15k speed.