On board a laden bulk carrier on passage, the engine room staff were holding a meeting before starting work for the day. At this time, in anticipation of a larger electrical sea load, auxiliary engines (A/E) Nos. 1 and 2 were on a parallel load-sharing configuration. All the engineer officers were present in the engineering control room (ECR), and the engine ratings were carrying out their assigned tasks, when they noticed flames between the two running generator engines. The fire alarm system activated, and the engineers immediately tripped the main supply breakers on the switchboard, stopped the auxiliary engines and all other running machinery, whilst the emergency generator came on load. Within seconds, thick black smoke seriously reduced the visibility in the engine room, forcing all the staff to evacuate the machinery space. While the crew mustered, the ventilation trips, flaps and quick closing valves were operated, and the E/R was battened down. The Self-Contained Breathing Apparatus (SCBA) team #1 then entered the space and extinguished the fire with portable and semi-portable extinguishers. The crew continued to monitor the space from various locations for hot spots. A few hours later, they made another entry to verify that the fire was completely extinguished. Subsequently, after carrying out all the appropriate operational safety checks, Aux. Engine #3 (located on the lower platform), main engine and other machinery were restarted, and the vessel resumed her passage. Immediate actions 1. Owners were informed and kept updated on the situation/developments; 2. P&I Club and Hull & Machinery underwriters were informed; 3. The classification society was informed, and urgent attendance was requested at the next port. Root cause/contributory factors Suddenly, shearing off of one of the three bolts that secures the lubricating oil filter cover of A/E #2. The cover was displaced, and lube oil under pressure splashed onto various hot components of both running generator engines and ignited. Although the engineers reacted correctly and quickly stopped both generator engines, the lube oil priming pumps continued to operate, powered by the emergency power source. This resulted in the unintended spill of all the lube oil in the sump of the A/E #2 engine, which fed the fire. Suspected improper tightening of the filter cover bolts and lack of proper inspection, especially as it is known that these fittings could be subject to wear down or loosen due to vibration / internal pressure; The presence of combustible material, such as felt filter covering the engine turbocharger (T/C) blowers, and plastic light fixtures, added to the intensity of the fire. Corrective/preventative actions A special safety meeting was held on board to emphasise the importance of carrying out risk assessments, toolbox meetings and discussing all the anticipated risks when allocating jobs for the day. Anti-splash sheaths, guards for filter covers and extra securing arrangements for cover bolts were fabricated and fitted for all lube oil pipes and filters on generator engines, even though these are not formally required. Renewal/cleaning of the filters and other critical parts of the generators will be supervised by the senior engineers. Restoration of all engine room areas affected by the fire (coating renewal, renewal of damaged electrical wires and other associated fittings) was commenced immediately. All auxiliary engines were made fully operational and successfull