2. Difficulties experienced lately in the field, which related to fuel oil
Among the trouble reports related fuel oil quality, the under mentioned two cases are the most popular and used to cause a fatal damage to marine engines.
1) Abrasive wear due to Cat-fines
2) Scuffing and adhesive wear probably related to the fuel quality
2-1. Two cases of fuel related problems
As typical fuel oil related problems happened on marine engines lately, I would like to introduce the followings two cases.
Case 1. Abrasive wear of cyl. liners and piston rings
One marine engine had been having a satisfactory service record for more than one year since commissioning. Suddenly, piston rings and cyl. liners wear were accelerated. To make the matter worse, when sudden increase of wear was noticed, any measures were not taken. In the inspection after several months, cyl. liners and piston rings were worn and typical abrasive wear due to cat-fines were observed. Especially, in replica observation of piston rings replaced before and after excessive wear started, they gave us a clear evidence when the piston rings wear started.
Case. 2 Adhesive wear
In this case, according to the temperature at piston under space, the increased wear of cyl. liners and piston rings started shortly after a certain bunkering. The engine had been operated continuously until a maker's service engineer visited and confirmed an abnormal surface looking on cyl. Liners and piston rings. In the inspection work of the cause of difficulties, we found that the bunker supplier reported the fuel properties to the ship operator wrongly, especially S-content.
3. Important steps to solve the difficulties in the field
In our after sales service activities of an engine builder, we are spending our utmost efforts to recognize and settle the following items clearly, in order to take proper measures in short time and give preventive measures against reoccurrence of similar difficulties.