Petrobras of Brazil Orders Bulk MTU Series 4000 Diesel Generator Sets

1. Project Background: Modernisation Mandate for Petrobras Offshore Fleet

Petróleo Brasileiro S.A. (Petrobras), South America’s largest oil and gas producer, heavily relies on offshore supply vessels and oil spill response ships to deliver supplies to offshore drilling platforms and tackle offshore oil leak emergencies. Conventional generator sets installed on its ageing fleet suffered persistent drawbacks including excessive emissions, high failure rates triggered by salt fog corrosion and unstable load output. Meanwhile, Brazilian maritime authorities mandate that all offshore vessels comply with IMO Tier III, the strictest global emission standard for marine equipment.

In 2025, Petrobras launched an international tender for 10 newly built special-purpose vessels, calling for marine diesel generator sets featuring regulatory compliance, robust resistance to marine corrosion and stable round-the-clock performance. Detroit Brasil, a local Brazilian shipyard, undertakes overall vessel construction, while Starnav Serviços Marítimos, a well-established South American shipping firm, takes charge of fleet operation. After rigorous salt spray endurance testing, full-load durability trials and certification verification across bidders, Rolls-Royce MTU secured the exclusive supply contract for all onboard power generators. The deal covers 40 units of MTU 16V4000 16V4000G14F M33S diesel engines dedicated to power generation, which will be assembled into fixed marine generator sets as the sole power source for the 10 vessels.

The fleet consists of six offshore platform supply vessels and four professional oil spill recovery vessels. Upon delivery, these ships will operate continuously along Brazil’s eastern Atlantic offshore oilfields, enduring harsh working conditions including heavy salt exposure, high humidity, tropical heat and constant ocean vibration.

2. Complete Hardware Configuration & Marine Customisation of Generator Sets

Each vessel is fitted with four complete MTU diesel generator sets, amounting to 40 units across the entire fleet. Modified from land-based MTU Series 4000 generator models, these units undergo comprehensive marine adaptation to withstand vessel vibration, seawater corrosion and the confined layout of engine rooms.

2.1 Power Parameters and Load Capacity

The MTU 16V4000 M33S power generation variant is calibrated for Brazil’s 60Hz grid frequency. Each generator delivers steady rated power capable of simultaneously supporting deck lifting equipment, crew living quarters, fire protection systems, navigation radar, sewage treatment gear and high-flow pumps for oil spill recovery. Multiple units run in fully automatic parallel operation, intelligently distributing loads under sailing, berthing and operational conditions. If one generator malfunctions, the remaining units automatically boost output to compensate, eliminating the risk of total power loss onboard.

Equipped with MTU’s fourth-generation electronically controlled common rail fuel injection system, the engine maintains stable fuel injection amid vessel rocking. Normal operation is guaranteed even with the ship listing up to 15 degrees, adapting to rough ocean sailing conditions.

2.2 Anti-corrosion & Tropical Marine Adaptation

Engine blocks, pipelines and base frames receive dual-layer epoxy anti-corrosion coatings. The air intake system integrates seawater mist traps and dual-stage air filters to block salt fog and ocean spray, preventing rust and abrasion of fuel injectors and cylinders. Factory-designed high-temperature radiators accommodate year-round tropical ambient temperatures above 35°C along Brazil’s coast, preventing power derating caused by overheating inside enclosed engine rooms. All electrical control cabinets adopt IP54 waterproof and dustproof sealing to resist dampness and condensation at sea.

2.3 Full Compliance with Emission Regulations

Every MTU generator set is paired with HUG selective catalytic reduction (SCR) denitrification aftertreatment devices. The complete powertrain fully meets IMO Tier III marine emission rules, drastically cutting nitrogen oxide emissions. Vessels equipped with this setup have unrestricted access to all regulated offshore waters of Brazil, the Caribbean and major ports across South America without port entry bans due to non-compliant emissions. The compact aftertreatment assembly fits neatly into cramped marine engine rooms without occupying valuable cargo space.

2.4 Fuel Compatibility & Long-service Maintenance Design

The engine runs smoothly on standard marine diesel, blended HVO (hydrotreated vegetable oil) or 100% neat HVO. Renewable fuel usage slashes carbon footprints by up to 90%, aligning with Brazil’s maritime low-carbon roadmap. Maintenance intervals are optimised for offshore scenarios; under regular cruising conditions, engine oil and filter service cycles extend to 800 operating hours. This suits long-distance voyages that last weeks with no port access for maintenance. All wearing parts follow global MTU standardisation for readily available spare parts across major South American ports.