CMT unveils new tech to prevent cylinder scuffing

“There is no system to detect scuffing at an early stage. The only thing which is around is a cylinder liner wall temperature measuring device,” says Winkler, adding that given the heat produced in the combustion chamber, discrepancies are difficult to spot.

Scuffing only impacts two-stroke units because, explains Winkler, of the much slower movement and the very long stroke. This means the lubrication film is very long on the liner wall and needs to stay there while on four-strokes with 600 RPMs or 900 RPMs it’s permanently lubricated. The pistons in a two-stroke engine move very slowly over large distances with lubrication challenges and the lubrication can break.

At this year’s SMM, Winkler said that some of the largest manufacturers of 2-stroke engines had been to visit his company’s stand, which given the possible outcomes of scuffing is unsurprising.

“It’s dangerous, because when the main engine stops working in the middle of the ocean it’s not a nice change! It’s a catastrophic failure,” says Winkler with a hint of mischief.

So how does it work? It doesn’t use the temperature of the engine room due to reasons mentioned above nor does it look for visual clues of scuffing. CM Technologies uses acoustics, it hears when the engine is in peril.

“We listen to every revolution of the crankshaft. We listen to the scratching noise in the liner. And the big challenge is to listen only for a fraction of the second when there’s no other noises, because we have the explosion, valves opening there’s a lot of noise in the engine room,” says Winker, adding the acoustic emission sensor detects the slightest changes in vibration which can be noticed during operation. Long time trending will reveal the lubrication problems so actions can be taken to prevent deterioration of the engine.

While an engine can still run with all its cylinders scuffed, the costs involved with letting an engine get into this state make it a far from an ideal set of circumstances. For instance commercial vessels could see cargo shipments delayed, meaning not just repair bills as a result of scuffing but legal costs due to breaches of contract.

Unsurprisingly, companies which have displayed an interest in CM Technologies scuffing sensor include some of the largest players in the marine market. “One big Danish company has huge interest in this technology, because they have big problems, not on all ships, but those with engine types that are prone to scuffing,” says Winkler.

With manufacturers such as WinGD and MAN ES offering warranties on their two-stroke engines, it’s surely only a matter of time that before offering these guarantees, the companies insist on shipowners using CM Technologies’ product.