Caterpillar and Cat dealer repower Harley Marine tugboats in California

(OAKLAND, Calif.) — Replacing the prime engine in a seafaring vessel to meet modern emissions laws can be a major challenge. For many vessel owners, the option to retrofit existing engines is an attractive alternative to implement compliant power solutions into their operations. Recognizing the need to provide flexible, comprehensive solutions to help customers address the increasingly complex emissions regulations, Caterpillar unveiled the EPA certified Cat®  3500 marine emissions kits.

Bay Area tug and barge operator Harley Marine Services was eager to incorporate sustainable, efficient power solutions into their vessels and reached out to Cat Dealer Peterson to evaluate viable options for several vessels in their fleet. After close collaboration with Peterson, Harley Marine Services elected to install the 3500 marine emissions kits, becoming one of the first customers in North America to adopt the innovative technology in their tugs. Peterson installed the 3500 emissions kits on 6x Cat 3516B marine engines in three different tugs, upgrading each vessel from EPA Tier 0 to Tier 2 while simultaneously improving the efficiency of their vessel.

“The advantages of utilizing a 3500 emissions upgrade are attractive for many of our customers,” Randy Richter, Peterson parts and service support representative commented.  “The customer doesn’t have to take his vessel out of the water, get the hull cut, and have the old engine removed to fit an engine with a different footprint than the one it replaces. It allows our customers to proactively incorporate compliant power solutions into their vessel while minimizing vessel down time.”

The Cat 3500 Marine Remanufacture Program applies to many commercial engines flagged or registered in the United States, and the requirements include a 25 percent particulate matter reduction at overhaul. By replacing the mechanical unit injector (MUI) system and other associated components on the engine, the upgrade kits offer vessel owners an in-hull solution that exceeds the requirements, and offers operational benefits.

Reducing emissions is a key imperative within the Caterpillar sustainability strategy and the 3500 Emissions Upgrade Kits are an example of aligning sustainability with innovation to help our customers. Aside from the compliance and environmental benefits, an upgrade from a mechanical to an electronic EPA Tier 1 or Tier 2 configured engine can also result in numerous operational improvements. These benefits include improved diagnostic and display capabilities as well as smoother overall operation. As confirmed by multiple customers, an upgrade solution during the overhaul can result in lower vibration and noise levels, and a significant fuel savings. A lesser known advantage of electronic fuel injection engines is that they offer superior brake specific fuel consumption in the midrange versus a traditional mechanical fuel injection engine.  “In many cases, we observe that our customers operate a significant percentage of their time below the rated power and speed, meaning that this upgrade kit will translate into both emissions reduction and operating cost savings over time,” P. Jaime Tetrault, Caterpillar Marine Power Systems product support director noted.

Customers interested in learning more about Cat Emissions Solutions should visit the Caterpillar booth # 2802 and 2902 at the show. For up to the minute updates at the show, please follow us on Twitter: and Facebook: using #catatwbs. Unable to make the show? Learn more at our Marine Customer Resource Center: Bay area customers can learn more about Peterson at

By Professional Mariner Staff