Page 34: of Marine Technology Magazine (January 2021)

RESEARCH SHIPS RV Roger Revelle

One speci? c area was taking the decision to replace a noisy,

Research Vessel inef? cient bow thruster with a new retractable unit from ZF, a change which drops the bow thruster – and the related noise (R/V) Roger Revelle and vibration related to its operation – several feet beneath the hull, making living conditions on the ship more palatable and is back at work after a midlife re? t involving upgrades from enhancing the collection of scienti? c data.

top to bottom, bow to stern. The ship is owned by the Of? ce of

While Paul Mauricio, Port Engineer, and his team did exten-

Naval Research and has been operated by Scripps Institution of Oceanography at the University of California San Diego sive work to improve the ef? ciency and noise signature of the original bow thruster, including pulling, machining and ? ne- since 1996. It is one of the largest ships in the U.S. Academic tuning the impeller on the water pumper, “It would max out at

Research Fleet, an important asset to U.S. oceanographic re- about 270 rpm, it would start to cavitate and it would shake the search due to its range, payload, duration, and ability to safely entire boat.” As Appelgate and his scienti? c colleagues will conduct scienti? c operations in remote areas around the globe. attest, external noise and vibration at sea is not a friend of “Roger Revelle isn’t just revitalized, it is better than new,” said good science, particularly as research ships like the RV Roger

Bruce Appelgate, associate director and head of ship operations

Revelle use the bow thruster for many hours and days at a at Scripps Oceanography. “The midlife re? t was an opportunity stretch to stay on station while equipment is in the water.

to apply everything we’ve learned about the ship since 1996, in

With the new retractable bow thruster from ZF, “once it’s order to make a great research vessel even more effective.” deployed, the noise is below the ship, not transmitted through

The $60 million re? t was supported by the Of? ce of Naval

Research (ONR), National Science Foundation (NSF), and the hull” said Mauricio. While the performance of the unit was critical, so too was being able to ef? ciently ? t it into the ship,

UC San Diego, and highlights included: minimizing the level of modi? cation work needed to get the • Repower: The repowering involved replacing the six new unit installed. “One of the driving factors to (which unit existing air-cooled generators and split electrical bus we picked) was the fact that it would ? t in a retro? t without con? guration (auxiliary and propulsion separate) with drastically modifying the entire bow,” said Mauricio.

four new water-cooled generators and an integrated bus

While noise and vibration is bad for science, it’s equally bad (auxiliary and propulsion together). This included re- for quality of life on any ship. “On Roger Revelle, up in the placing major switchboards and transformers, as well as bow is where a bunch of our berthing quarters are located,” the propulsion motors and drives.

said Appelgate. “Typically that’s where the graduate students • BWMS: An Optimarin ballast water management sys- get put, so I was stuck up there (a few times). The reason you tem to help stop the spread of invasive species.

get ‘stuck up there’ is because it was noisy as heck because • Bowthuster: The installation of a new retractable ZF you were next to that (old) bow thruster. Even without cav- bow thruster to improve performance, vibration and noise.

itation, it was super loud. By installing the extendable bow • Cranes: An overhaul and replacement of overboard thruster, it moves the source of noise farther away.” handling systems, with new cranes, a refurbished A-frame and hydrographic boom.

Better Science Minus the Bubbles • Scienti? c Gear: The addition of a scienti? c instru- “I’m a geologist,” said Appelgate. “Back when I was doing mentation gondola.

research, my interest was in sea ? oor mapping,” and I sailed on the Roger Revelle as a scientist before I worked at Scripps.

Lessons Learned

Ship design, construction and operation technology has According to Appelgate, the con? guration the ship’s mapping sonars when built in 1996 was “the worst place you could pos- changed mightily since RV Roger Revelle was delivered near- sibly pick on the ship for your mapping sonars.” ly a quarter of a century ago, and the team tasked to design, “Ships like Roger Revelle are very broad and not super long; out? t and update the ship sought to use ‘lessons learned,’ both so it pitches a lot,” said Appelgate. “As it goes through the from the operation of the ship itself as well as experience from recent re? ts of other research vessels in the U.S. Academic water pitching, it makes lots of bubbles and the bubbles sweep down along the hull. Bubble masking is something that we

Research ? eet. A big factor in many of the re? t decisions, in understand very well now, but not so much back in 1996. The fact, were the shared experiences from the re? t of the Thom- place where all the transducers were (originally placed) were as G. Thompson, operated by the University of Washington. right in the place where bubbles would wash down and, basi- “One of the great advantages that we’ve got at Scripps is being cally, wipe out your sonar signals.” part of the community of ship operators in academic research “In the period since then, there’s been a lot of work done on ? eet,” said Appelgate. “They shared everything with us, (in- how to mitigate that on a vessel without rebuilding the ship.” cluding) their lessons learned.”

The answer was a gondola that puts the transducers a few 34 January/February 2021

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