Marine engine makers gear up for stiffer emissions standardsOct 1, 2013 11:04 AM
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Maintenance intervals and durability are unchanged in most cases. But there is one significant caveat.
For engines with the high-pressure common rail injection, fuel cleanliness will be critical for durability. Contaminated fuel could clog the high-pressure injection system that has very tight tolerances. Older engines had filters in the 7- to 10-micron range. The new engines have filters in the 2- to 3-micron range, along with the larger filters fitted on previous models. Instead of a single filter, an engine might have two or three filters to inspect and change.
“As all manufacturers increase the pressure of the fuel system, it’s very important that the fuel is clean,” Sherman said. “Unlike the old days when you could run anything through the engine, it will cause failure to the fuel system if you don’t pay attention to the fuel quality and fuel delivery to the engine.”
Operators should check the fuel supply for contamination before it’s pumped onto the vessel.
“We’re seeing operators sample fuel when it comes off the truck and sampling it again before it reaches the engine,” Sherman said. “It’s important to verify the fuel at delivery to ensure that it meets the standards required by the engine manufacturer.”
However, early testing has shown that while Tier 3 engines are designed to run on ultra-low-sulfur diesel, they may not be overly finicky about fuel quality. Cummins has Tier 3 engines operating off the coast of West Africa and it has done testing with high-sulfur diesel and some low-quality fuel and found no problems, Aufdermauer said.
Regardless, manufacturers have worked to keep maintenance requirements the same as on Tier 2 engines.
“The service intervals are the same, but there are more filters to check,” Aufdermauer said.
For a newbuild or a repower, the fuel system will require greater scrutiny than it has in the past.
“Optimizing the fuel system is crucial,” Sherman said. “If it’s taken care of properly it shouldn’t be a problem, but if it’s not taken care of and filters are not changed or there’s a limited filtration system, vessel operators will see injector failures and things of that nature.”
However, failure of injectors or other components due to fuel contamination won’t be considered a warranty item.
“A warranty is a way for manufacturers to cover defects of workmanship and components, so if we determine a failure is not based on workmanship or a component, then it’s not a warranty situation,” Sherman said.
Vessels that refit older engines may see some operational benefits from engines with the new technology.
“We hear that when ships repower, they see fuel consumption and performance improvements and maybe gain a little bit of boat speed because the engines may be lighter,” Micu said.
Depending on the size of the vessels, some operators adopted Tier 3 engines ahead of the requirements to meet more stringent local conditions. For instance, Norfolk Tugs installed Tier 3 engines in its vessels that operate in New York Harbor.
“There are some customers going to Tier 3 because they want to reduce their emissions, and there are certain companies where that fits their corporate mission and vision,” said Scott Rath, sales manager for Cummins Commercial Marine.
Because it’s a relatively short window until the Tier 4 regulations take effect for the larger engines, some manufacturers will limit how many engines they offer under Tier 3 while gearing up for Tier 4. For other manufacturers such as John Deere, Tier 4 won’t come into play because all their products fall into Tier 3.