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Workboat Design: Interview with Bob Hill
Robert (Bob) Hill of Ocean Tug & Barge Engineering Corp., of Milford, MA has specialized in the design of AT/B's for many years. Hill's name is, in most maritime circles - here and across the big pond - synonymous with the words "articulated tug/barge systems."
As probably the world's most experienced designer of large
articulated tug/barge (AT/B) systems, Hill's success comes, in
part, from a willingness to innovate. Ocean Tug & Barge
Engineering Corporation and Robert Hill are the co-inventors of
the Intercon Connection System. In a nutshell, his firm has had a
hand in over 70% of the operational AT/B's in service in America
- including, 80% of those built or converted since 1994. In large
part due to Bob Hill's efforts, the AT/B is now a familiar
standard in the U.S. flag fleet for coastal, Jones Act and some
inland applications. This month, Hill gives us an update on
what's new in the world of AT/B's, why, and what's looming just
over the horizon.
A flurry of replacement tonnage has occurred in the last
five years, but the need for coastwise tonnage, especially in the
tanker sector, is slowing. Are other opportunities in other
sectors making up for that?
The short answer is YES. A longer, more detailed narrative would
run afoul, in my case, of the myriad "Confidentiality Agreements"
that we must sign onto with clients. That said; we work with
unusual AT/B's; tackling the new projects that surface. We have
done everything from the Mosaic/Savage Ammonia Carrier AT/B, to
the Great Lakes Dredge and Dock AT/B hopper dredge, to the SeaOne
Maritime CGL AT/B's and Minyan Marine's "Chemitainer" design. We
are currently servicing projects that run the gamut from LNG
carriers, to large bulk carriers, to container carriers, to
bunkering barges to railcar carriers. If a ship can do it - an
AT/B can do it. It is that simple. We are also seeing inquiries
for smaller AT/B's - tugs under 3000 HP and barges under 250
feet.
Some aspects of U.S. yards are doing well - ferries, for example.
How active is the ATB buyer market? Has it changed much? What are
they asking for? Rank these in order of preference for today's
domestic operators.
We are seeing a wider range of clients than perhaps 10 years ago.
We continue to design for traditional clients such as tug and
barge companies, but increasingly we are being contacted by
traditional shipowners, commodity brokers, and industrial
clients. Our workload potential has expanded so much that it at
times eclipses our staff size and to that end, a major
announcement about our firm is coming in the next month.
(1.) Different Service (as compared to oil and product carriers);
(2.) Different Size Units (both larger and especially smaller);
(3.) Higher Speeds (and less fuel consumed vs. traditional); and
(4.) Propulsion Changes (to make number 3 possible).
Where is the biggest opportunity for future ATB growth?
Why?
We feel that the introduction of the AT/B into services and/or
geographical areas that it had previously not been employed is
future of the concept. If it can move by water, an AT/B can move
it. This includes the use of AT/B's that can transit both deep
and shallow water, large AT/B's (we have a design for a liquid
carrier of 100,000 DWT), LNG, and CNG gas carrier AT/B's, and
vehicle carriers. The list is almost endless.
Q-LNG is building an ATB LNG bunker vessel. What else exciting or
cutting edge is being planned or underway at the moment?
A long time ago, we designed a 10,000 cubic meter AT/B LNG
carrier for Argent Marine. We remain in contact with Argent
regarding future work, so LNG is basically on the horizon in
general. However the expected rush to LNG never materialized
fully, and most LNG projects we deal with are on hold. Other
projects to move gasses in other places by various means are
alive and well. For example, the Mosaic/Savage Ammonia Carrier is
doing incredibly well, and is delivering product at a rapid pace.
The iconic ATB changed the marine transportation industry in many
ways - in terms of economics, operating practices, etc. -
especially for tanker operators. In what way did its advent
eventually impact the overall marine transportation
industry?
AT/B's married low-cost marine transport with reliable marine
transport. Barges have always been a less expensive option to
move cargo, but towed barges were slow, fuel-inefficient, and
unreliable in bad weather. By good fortune, the push toward the
AT/B occurred right about when the petroleum industry was
changing from a 'full inventory always' model to a "just in time"
model. The latter would have killed off the towed barge market
because towed barges in the Northeast were historically as much
as 40% delayed. When Mobil approached us to design their 140,000
BBL AT/B for Northeast service, the entire reason to even
consider an AT/B was weather-reliability. Mobil did not want a
towed barge. The choice was a tanker, or a provable AT/B concept.
The AT/B won out and while the Exxon-Mobil merger changed the
trading patterns that created the unit in the first place, she
did exactly what was expected of her while in service. That unit
still works for Kirby Corp. AT/B's did not occur suddenly.
Pioneers like Ed Fletcher and the Bludworth family paved the way.
These early systems, while not perfect, did open a small window
for consideration as operators openly queried whether or not the
shortcomings of each could be improved. Once the Intercon System
appeared, then Articouple began selling in the US, and JAK made
an appearance, the flood gates opened. The entire narrative of
how the Intercon System came to be is a story, in and of itself.
The credit for the success of the AT/B is a story of engineering,
risk-taking, and a rapid industry-wide acceptance of a concept -
something which is quite rare on the waterfront.
In terms of design changes, what is the most innovative thing
that has hit your sector? Why is it important?
The entire concept itself is the truest 'innovation.' However,
the use of DC-bus/inverter-based electric propulsion systems will
allow a reduction in emissions and fuel consumption. Beyond that,
we now have model tested enough units to know that we can extend
the speed range for large AT/B's up into the 17 knot range (with
about the same power as a comparable sized ship), and not 'blow
the doors off horsepower' as has been the case historically. The
increase in speed will be the next big change we will undergo. We
are pursuing that to see if there are any hidden penalties such
as steerability, and meeting IMO 751, or creating something too
costly to build.
Container on barge - it is being widely discussed today. Are
there any in production at moment (fit for purpose) and/or in
planning? Does the ATB have an inland future?
Yes, we believe it does. A few years back, we designed a unit for
use in China that was capable of both river and ocean transit. We
designed an entirely new hull shape for it. Container AT/B's can
run the gamut from simple deck barges with lashings to fully
cellular barges like Minyan's Chemitainer design. Units capable
of ocean and rive transits will have to be a different kind of
animal to allow for both. Then you have canal-constrained
services like the NY Barge Canal, where waterborne container
moves are limited not only by draft but by the small locks of the
canal. Here, highly specialized high-value container moves (such
as chemicals) may be feasible. A NY Barge Canal-capable AT/B
could run from New York City to Chicago without any towing, but
the cargo would need to be high value and move only from April to
late November. Those problems do not exist on the great river
systems.
Are you seeing a (more pronounced) move towards LNG as a fuel in
this sector? Has the bunkering discussion - midstream versus
alongside advanced any further with the Coast Guard?
There is no big move in LNG fuel for AT/B's as yet that we can
see - unless the barge is carrying LNG. We have designed such
tugs for Argent Marine, and others, where LNG is the cargo. LNG
has not really caught on in the US as a propulsion fuel for tugs
in general, let alone AT/B's. The low cost of diesel has hurt
LNG, as has the now proven domestic crude oil reserves. The
biggest detriment is the cost of the tug and machinery plant to
burn LNG as propulsion fuel and the inability to carry enough of
it to go long distances. As advancements in LNG fuel storage come
along, we may solve the storage volume issue, but not the cost of
it. Unlike railroads that can by law place a large LNG fuel
tender between locomotives and connect the fuel to the locomotive
via vaporizer/hose arrangement, the U.S. Coast Guard has been
opposed to such arrangements where large fuel amounts are carried
on the barge. One of our clients has developed a safe breakaway
system to allow that between and AT/B tug and a barge, but the
USCG has not approved such things. Certainly, we have developed
tugs that can carry LNG or CNG fuel, at least conceptually. Thus
far, no one is biting , but that may yet happen.
For the larger coastwise units, is Tier 4 the law now, and if so,
what's the preferred method to achieve that standard in newbuild
tonnage today?
We have designed Tier 4 AT/B tugs and one is nearing completion
right now for Reinauer. Considering the ways a diesel can be made
T4 compliant, you have three basic choices. You can use an EGR
engine, you can use an SCR-based engine with urea, or you can
burn LNG in some cases. With EGR, there are questions of wear and
other issues with reintroducing exhaust gas back into the
cylinders. The Reinauer tug has GE T4 engines and they (GE) have
the most experience with this, with a large number of locomotive
in US service to draw experience from that are fitted with GE T4
engines. With SCR/Urea engines, EMD has come with a T4-compliant
2 cycle engine based on their highly successful 710 series
engine. However, there is a cost associated with purchasing and
storing the "DEF" or "diesel exhaust fluid" in the tug. We have
fully designed a 16,000 HP AT/B ocean class tug with this system.
One client elected to change to the EGR design engine, another is
sticking with a diesel-electric, EMD T4 solution with urea.
Neither design was overly-complex to design. The GE installation
is clean and easy to lay out, with great engineering support
behind it, as is the EMD-urea-based setup. American diesel
manufacturers in these power ranges have a robust investment in
the rail industry and solutions must fit inside a locomotive
carbody, as both the GE and EMD solutions, do. From my point of
view as a naval architect, either the GE or EMD solution is,
engineering-wise, equally easy to do and install.
Is the urea storage issue giving ATB's any problems - especially
in terms of the fact that ATB's tend to have longer voyages and
need robust endurance specifications?
Not at all. We had no issue finding space for urea tanks on a 160
foot, ABS-approved 16,000 HP design. The amount of urea required
is a percentage of fuel consumed and easily accommodate on this
sized platform. When we first started on the urea-based boat we'd
heard all the horror stories about carrying urea, but none proved
to be true.
The safety record of ATB's is by and large good. And, it has
gotten better. Discuss some design changes that have, over time,
made it better.
First of all we and other designers try to make quiet, spacious
and comfortable tugs. This means that the crews are more rested
and alert. They also have an easier ride than bouncing around the
ocean on the end of a long towing hawser. There is a generally
accepted link between crew comfort and performance on the job.
You need only look at Mr. Guidry's supply vessels as proof of
that. Secondly, we build very strong tugs. A class
society-minimum tug will never come off our boards here. We know
AT/B's well enough to know where to put the steel in them. The
same holds true for the design and practicality of machinery
systems. Finally, and most important, the crews, and owners
themselves are conscientious, safety-minded people. The safety
culture in most tug and barge companies is set to the highest
standard and where it is not, I hear about it from the crews. I
can say that none of our clients are less than perfectly devoted
to safety.
The dreadful condition of the domestic offshore energy
situation notwithstanding, you've been rethinking the iconic
design of the traditional OSV. What advantages would the ATB
bring and are you planning DP capabilities, etc?
The "Provider" class AT/B (Patent filed for) is an effort to
rethink the entire OSV idea. Multiple cargo boxes are possible
with a lesser number of tugs to handle them. This is a perfect
service for "drop and swap" type operations. A barge can be
loading while the tug is taking a second barge out and when the
tug returns, barge number two is ready to go. We envision the tug
staying with the barge at the rig, and not leaving it unattended.
For the same size tug and crew, you can have twice the cargo
deadweight of a single supply boat. You pay for one tug and crew,
but loading is done with shoreside crews while the tug is away.
The tugs and barges will be fully DP-capable, and the machinery,
first class. We are happy to share the concept with prospective
customers.
Jul 5, 2018
