Go Behind the Iron: the Details on the New 3516E Tier 4 Final Engine

The Cat® 3500 engine series is already one of the most proven engine systems in the world, and it’s getting better with the shift to U.S. EPA Tier 4 Final emission standards. The 3516E model, specifically, is designed for marine operations and offers the best PM and NOx reduction technology, in the form of an improved SCR system. Along with SCR comes an impressive collection of features and options that can be tailored to any marine operation, as well as compliance with essential safety regulations.

The shift to Tier 4 Final

The EPA’s move to Tier 4 Final emission standards may not have garnered much attention among machine owners, as it’s strictly a change on the manufacturing side. However, it will have an impact on machine owners, so it bears explanation.

Tier 4 Final is the EPA’s next step in emissions reductions, and as of January 1, 2016, these standards apply to a number of Cat engine models. This includes the vaunted 3500 series of Cat engines. Under Tier 4 Final emission standards, both PM (particulate matter) and NOx (nitrogen oxides) are to be reduced greatly. There are a couple ways for manufacturers to achieve this, but SCR (selective catalytic reduction) stands out as the most effective.

And the Caterpillar version of SCR is the pinnacle of the technology. SCR was already preferred for the improved fuel economy it offers to owners – which can be up to 5 percent in some instances. Caterpillar has designed its version of the technology to be more reliable, easily serviced and more compact. All of these gains mean that total cost of ownership is less, even when accounting for the addition of the diesel exhaust fluid that makes SCR work.

The 3516E Tier 4 Final

Tier 4 Final and Cat SCR technology, then, will help conserve natural resources and machine operators’ costs at the same time. But there’s more to the 3516E than just better emissions.

The 3516E pushes out a max continuous rating of 3385 hp and has been designed with marine operations in mind. The engine is compatible with Safety of Life at Sea (SOLAS) regulations and is Marine Society certified. Among the SOLAS additions are several heat shields, installed around the exhaust manifold, aftercooler and the turbochargers. The heat shields are designed for serviceability, so technicians can get in and out with minimal downtime. Explosion relief valves are also built into the 3516E, which align with Marine Society regulations.

The 3516E also offers a closed crankcase ventilation system option, which allows operators to send emissions back into the engine intake instead of venting them separately out of the vessel.

Several cooling options are available with the 3516E, including a keel cooled option or a plate heat exchanger, which is built with the water’s thermal expansion accounted for.

Finally, an electronic oil mist detection system can be incorporated into the 3516E (for engines rated at 2250 bkW or higher), which allows for more reliable and more expedient detection of oil misting. 

There are already thousands of 3500 engines operating in marine applications worldwide. More than 26,000, in fact. And with the 3516E Tier 4 Final, Caterpillar continues to show why more vessel owners prefer Cat power solutions to competing options.




Find out more about the technology behind our EPA Tier 4 Final and IMO Tier III emissions solution by exploring our FAQs, case study and customer story.

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What Customers Are Saying

Tier 4 Marine Engine

Reliable. Fuel-efficient. Easy to maintain. Flexible to install. Learn more about what customers are saying about the Tier 4 Marine Engine.

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Support the SCR Solution

Get answers to common product support and maintenance questions on Selective Catalytic Reduction SCR, the Caterpillar technology to meet marine Tier 4 and IMO III emissions regulation.

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SCR delivers on emissions and efficiency

Selective Catalytic Reduction (SCR): The simplest technical solution to meet restrictions on NOx emissions for ships is also the one that minimizes total cost of ownership while maximizing uptime, according to Caterpillar Marine.

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The 1-2-3 of SCR

Learn more about the marine-specific solution designed by Caterpillar includes Selective Catalytic Reduction (SCR) technology to meet Tier 4 Final emission standards with few or no changes from the Tier 4 Interim solution.

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