By Kenneth Stewart Naval Postgraduate School
MONTEREY, Calif., November 19, 2015 — Naval Postgraduate
School student Navy Lt. Cmdr. Korban Blackburn is developing an optimization
tool dubbed the Optimized Transit Tool Easy Reference, or OTTER, which has the
potential to save the Navy millions in fuel costs.
“Lieutenant Commander Blackburn’s thesis work is
contributing to the important problem of reducing fuel consumption in the
fleet. Reduced fuel consumption means lower operational costs, less sensitivity
to volatile fuel prices, and most importantly, reduced resupply needs --
meaning that ships are able to operate on station longer before they need to
rendezvous with a tanker for refueling,” said Blackburn’s thesis adviser, NPS
Assistant Professor Emily Craparo.
“If I can stay on station for an extra week without fueling,
I have optimized my operational capabilities. That’s the goal,” Blackburn said.
OTTER is part of Blackburn’s thesis project at NPS’
Department of Operations Research. Although not fully complete, it is already
garnering attention throughout the fleet and was recently awarded the Athena
Project’s Waterfront Athena Eight Admiral Sims Award for Intellectual Courage.
The Athena Project bills itself as an “innovation-fueled initiative to make the
Navy better through powerful ideas, unique solutions and intellectual courage.”
Finding Most Fuel Efficient Speeds
OTTER is used to determine the most fuel efficient speeds at
which to travel between two given points and helps mission planners to take
into account the effects of various speed combinations while incorporating the
impact of group transits and other variables when conducting mission planning.
“Every ship has a fuel burn-rate curve, which shows how much
fuel you burn for a given speed,” Blackburn explained. “Think of gears in your
car. Would you rather go fifty miles per hour down the freeway in first gear or
fifth gear? There is one gear that is the most efficient for a given speed.
OTTER helps us to determine which gear that is.”
What OTTER demonstrates is seemingly counterintuitive. On a
Littoral Combat Ship, for example, if you were ordered to steam at 17 knots for
24 hours, the average person in open water would likely set the ship’s speed at
17 knots and keep it there until he or she reached their destination. But OTTER
reveals that by steaming forward at 15 knots for 90 percent of the time and
traveling at 25 knots for ten percent of the time, you would still be able to
travel at an average rate of 17 knots over a 24-hour period, but would save
more than 400 gallons of fuel per hour.
Blackburn’s work builds upon work done by NPS Professor of
Practice Jeffrey Kline, Distinguished Operations Research Professor Gerald
Brown, Distinguished OR Professor Alan Washburn, and the late Distinguished OR
Professor Richard Rosenthal, which led to a 2007 patent for a ship’s Transit
Fuel Planner.
“The Transit Fuel Planner advises a specific ship, based on
its own fuel consumption curves, what is the most fuel efficient engineering
plant configuration and combinations of speeds to transit a certain distance in
a certain time,” Kline said.
Building on Prior Work
“[Blackburn] looked at this prior work and recognized that
in order for this insight to be most useful, we need to take into account
various operational realities,” Craparo said. “One thing to consider is that
ships often travel together in a battle group rather than alone as individuals.
For a battle group composed of different types of ships, it’s not so
straightforward to determine what speeds the ships should travel in order to
achieve a certain average speed.
“If the ships are assigned very different speeds, they may
become too widely separated while in transit, even if they all arrive at the
destination at the same time,” she continued. “Lieutenant Commander Blackburn
is also considering how to incorporate drills into the battle group’s transit
plan.”
Kline got the initial idea for The Transit Fuel Planner when
he took command of the USS Aquilla after graduating from NPS. Even in its
rudimentary state, Kline was able to realize significant fuel savings by
utilizing the system. He eventually returned to NPS and collaborated with
members of the OR department under an Officer of Naval Research program before
securing the Transit Fuel Planner patent.
Blackburn’s OTTER program simplifies the Transit Fuel
Planner, and makes it more user-friendly by graphing the results of various
algorithms and reproducing them in a simple, easy-to-follow chart.
“I wanted to make the [Transit Fuel Planner] easy to use. I
developed an Excel spreadsheet that can be given to someone aboard a destroyer,
cruiser or any fuel-burning Navy ship. Sailors won’t need a laptop or anything.
It’s literally just a piece of paper,” Blackburn said.
Collaboration Produces Results
Blackburn also worked closely with former NPS intern Brandon
Naylor while developing OTTER. Naylor came to NPS as an ONR Naval Research
Enterprise Internship intern. While at NPS, he worked at the university’s
Energy Academic Group exploring the applicability of various ship-board
efficiencies recommended by former NPS student Navy Lt. Dustin Crawford in a
thesis titled, “Alternative Practices to Improve Surface Fleet Fuel
Efficiency.”
Naylor eventually developed the Fuel Usage Study Extended
Demonstration program to test variant combinations of efficiencies in
Crawford’s thesis.
“I developed a program that allows me to set up to ten
battle groups and factor in schedules for them. You can build up different sets
of policies with different constraints and compare how much fuel has been used
per group, per hour,” Naylor said.
Naylor also spoke to subject matter experts and sailors
throughout the surface Navy to ensure that his algorithms were capable of
accurately predicting fuel usage in a variety of different maritime conditions
and within operationally imposed restraints, an effort that helped Blackburn to
solve some of the underlying problems that make OTTER possible.
Similar developments and collaboration between researchers
at NPS and ONR have made programs like OTTER successful in in the past.
Blackburn hopes that OTTER will contribute to efforts in the areas of
conservation, operational research, and efficiency
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