Fleet business is relationship business. Along with the day to day challenges, you get to know the individuals that have the tough job to get the work done. These relationships are what drives our staff and it happens to be tremendously satisfying work.
A few years ago, the AMNAV port engineering team approached MER to develop generator set repower solutions which could be applied to their Dolphin class, ASD tugs. AMNAV is a top tier maritime services company providing ship assist and offshore towing out of Oakland with their fleet of leading edge design tugs.
AMNAV has a proven reputation for high standards and reliability. The development of the specification for BOLLARD generator sets was driven by the quest for long term service life and superior reliability. The initial concept for these Dolphin class tugs was to include BOLLARD 99kW generator sets and we have since added 75kW to an additional tug.
By the end of 2021, the AMNAV fleet will have installed new MG99s on their Dolphin class tugs, Patricia Ann, Sandra Hugh, Revolution, and the Independence, and MG75s on the tug Liberty. In addition, BOLLARD gensets have been installed on the latest new tug in their fleet, the impressive, Sarah Averick. The AMNAV / MER partnership has been an excellent example of teamwork, pre-planning, and development to satisfy the needs of these tugs.
To extend life and reliability, the specifications included Marathon Mariner generator ends, developed for heavy duty application in a demanding marine environment. Mariner genset ends feature reinforced main stator windings, additional dip and bake cycles, and polybutadiene coating on the stator windings to minimize the effects of the marine salt laden environment. They are also equipped with a heavier duty rectifier assembly.
The Mariner models hold a relatively low operating temperature rating which maximizes electrical efficiency resulting in superior fuel economy. Permanent magnet generators (PMG) are standard equipment on BOLLARD generators to minimize voltage droop during motor starting. The dedicated excitation system is critical in the performance of variable frequency drives and boosts short circuit protection to 300%. The Digital Voltage regulator maintains output voltage at under .25 VAC variation from no load to full load to protect and extend the life of voltage sensitive driven equipment.
BOLLARD MG99s are powered by the finest marine engine in its class, the John Deere 4045AFM85. The 4045AFM85 is the premier engine of choice for heavy duty applications. MER modifies the engines during assembly adding more convenient service access and installing protection systems to alert the vessel of impending service concerns.
The BOLLARD design includes an engineered vibration isolation system. The units are mounted on IsoFlex’s highly efficient petroleum resistant isolators on our latest BOLLARD structural steel base frame. At 95% vibration isolation, this system results in reduced noise and vibration.
A component of particular focus by the AMNAV / MER team is the control and monitoring system. The BOLLARD digital panel is conveniently configured for each vessel to provide control, engine diagnostics, AC monitoring, service interval notice, and safety protection to meet AMNAV’s standards. Engine shutdown and alarm outputs are included to meet the latest US Coast Guard regulations. These control systems provide the chief engineers and other operators familiarity between vessels, a useful feature for operators as they move from one tug to another.
The AMNAV – MER partnership, from design to installation to day-to-day operation, has been highly rewarding. Recently, Milt Merritt, President of AMNAV posted online, “We are happy to partner with MER to upgrade our vessels with their state of the art (BOLLARD) generator sets.” We look forward to more collaborations with AMNAV in the future.
This article originally appeared in our Fall 2021 newsletter.
