1. 30 Surveyor • Summer 2007
D
ecisions made in the first 24 hours
after a marine casualty can greatly
affect a vessel’s chances of survival,
as well as the casualty’s impact on the marine
environment. With this in mind, the US Oil
Pollution Act of 1990 mandated that every
oil tanker have a vessel emergency response
plan that names the provider of its emergency
shore-based technical services. In response
ABS, through its affiliate ABS Consulting,
created the Rapid Response Damage
Assessment (RRDA) program, a vessel
emergency response service run by the ABS
Marine Casualty Response Center (MCRC)
in Houston, Texas. Its job is to provide
comprehensive support during a marine
casualty to the vessel, its owner or operator
and the salvors.
On 1 January 2007 a new requirement to
the International Convention on Prevention
of Pollution from Ships (Marpol Annex VI)
came into effect, mandating that all oil
tankers over 5,000 dwt have “prompt access
to computerized, shore-based damage stability
and residual structural strength calculation
programs” in the event of an emergency.
Made up of engineers and experts in struc-
tures, stability, machinery, operations and
survey, the RRDA technical team’s basic role
is to assist the vessel master and the operator’s
The Paramedics
of Marine
Casualties
The first responders to a marine casualty
can greatly affect its outcome.
B
eing prepared for an emergency includes
being familiar with the available tools.
Through regular training sessions and
drills, HECSALV users keep in touch with the
latest software developments and exchange
information on actual experiences and solutions.
Training in HECSALV is given by its lead software
developers – who are also practicing naval
architects – and gives salvors, class societies,
navies, coast guards,
shipowners and operators
a chance to find out
how the program is
used and to transfer
knowledge to the
users through
a breadth of
experiences.
In this way, HECSALV
continuously expands
its capabilities. Its ongoing
development includes incorporation into third-
party software as the engine behind specialized
user interfaces, finite element methods to handle
side forces and deflections, plan development
for dry docking, offshore platforms and stability
surfaces, complicated grounding arrangements
and two-ship problems (using its ‘macro’
interface and heavy lift analyses).
HECSALV utilizes a transparent XML based data
format to store both ship data and analyses. This
has already been used, independently, by others
to integrate HECSALV into both design and risk
reduction packages.
HECSALV is used frequently, all over the world.
Starting with the US Navy vessel Princeton
in the first Gulf war, which hit a mine, and
the British ship Trent, which burst into flames
while carrying gasoline after a collision in the
English Channel, to the removal of the SS Jacob
Luckenbach wreck that was leaking oil into
a marine sanctuary off California, HECSALV
has been applied to old, new and almost-
forgotten ships. Recent incidents where
HECSALV has played an important role include
the groundings of the MSC Napoli and the
MV Montrose, and the near-capsize of the
car carrier MV Cougar Ace.
Development of HECSALV Involves Users

2. 31Summer 2007 • Surveyor
technical personnel by calculating
the effects on hull structure and vessel
stability of various remedial actions.
Available round the clock every
day of the year, the RRDA program
currently supports over 1,100 ships
and, in what is an expanding off-
shore oil and gas business, a dozen
floating production units and a
handful of jackup drilling rigs.
The core of the RRDA service since
its inception in 1990 has been Herbert
Engineering’s HECSALV salvage engi-
neering software, which the responders
use to model vessels in distress and run the
response scenarios on which they base their
advice to the salvage decision-makers.
A vessel model is created when the vessel is
enrolled in the program based on a massive
amount of technical data supplied by the
owner. The process begins with digitizing the
hullform from such information as lines plans,
body plans and the table of offsets. The digi-
tized hull is then divided into holds, tanks
and other compartments using the general
arrangement and construction plans, while
internal volumes and other information are
validated against the vessel’s capacity plan.
Lightship weight and center of gravity are
added to the model along with allowable
shear force and bending moment values.
The midship hull girder section is modeled
and its section modulus compared against
existing calculations, and the entire model
is vetted by comparing load simulations
against the vessel’s loading manual.
It can take an experienced engineer 30 to
40 hours to create a vessel model. There are
over 1,100 models in the active program,
and the MCRC estimates that over the past
17 years RRDA engineers have created more
than 2,000 models in total.
Types of analysis performed during a casualty
include: stability with compartments
breached, water ingress and liquid outflow;
calculation of the still-water bending
moments, shear forces and stresses acting on
the hull girder; assessment of effective hull
girder strength and changes in stability result-
ing from offloading attempts; approval for
deballasting or cargo transfer plans; effects of
tidal change on salvage operations and on the
vessel itself; physical behavior of the vessel in
a grounding – which can mean changes
in stability and hull integrity under the
combined attacks of the ground, the tides,
weather, flooding and cargo loss or shifting.
During the response, information about
the vessel’s loading, physical condition and
behavior is relayed by the owner or crew to
the RRDA team, who input this data into the
model to create a live simulation of the ves-
sel’s situation. Once the model is updated, the
RRDA staff can simulate the vessel’s reaction
to various attempts to deal with the casualty.
Standard Approach to
Unique Situations
Each marine casualty is unique, and it is difficult
to know until the model is running whether
a situation is fairly simple or complex. But
whether it’s a bulk carrier stuck on a soft sand
bar in the tranquility of the Azores or a fully
loaded tanker aground in an ice-ridden pas-
sage hard by the Alaskan coast, the RRDA
team strives for as much standardization to
its approach as possible.
Within the first hour after the call, the team
assembles at the Marine Casualty Response
Center, contacts the vessel and gets the model
up and running. Within the next hour, they
create the casualty model and develop a
preliminary assessment of the situation. The
first response is usually an attempt to try to
free the vessel from its situation, or at least
mitigate the risks it is facing. Often, the team
recommends ballasting changes or lightering
operations at this stage. Sometimes, however,
the vessel can’t do very much; for example if
its pumping capacity is limited or if there is
no free space for cargo shifting.

3. 32 Surveyor • Summer 2007
“The great thing about computer models
is they let us try any number of mitigating
options to find the best one, without suffering
the consequences of bad decisions,” says
Fernando Lehrer, Marine Service Technical
Manager for ABS Consulting and former
Operations Manager of the MCRC. “HEC-
SALV, which may be the most widely used
salvage program in the world, allows us to
simulate the ‘what if’ questions of a response:
what will happen to the ship if we deballast,
or move 3,000 tons of cargo from Hold No. 4
onto a barge, etc.”
This is accomplished using two basic compo-
nents of HECSALV, the Ship Project Editor
(SPE) and the analysis tool. The SPE enables
the creation of the model with data from
drawings and hydrostatic analysis. Once the
model is done the engineers check it against
the existing ship documentation such as
the loading manual from the builders or the
hydrostatic tables and stability criteria from
the designers. The analysis tool allows them
to run simulations of the vessel’s reaction to
various response actions.
Because undersea topographic data is very
rarely on hand, one of the most difficult
aspects of a casualty to assess is exactly how
the ship is sitting on the seabed in a ground-
ing. Over the past year, Herbert developed a
sophisticated approach to the problem that
defines transverse loads and points of contact
along the breadth of the ship, called the
‘multiple pinnacle’ approach. Though refining
this model is a complex and difficult effort,
it ultimately helps the responders calcu-
late how much weight is needed to
be removed from the vessel for it
to float free.
Conditions aboard a vessel in dis-
tress can change dramatically from
one hour to the next. RRDA engi-
neers maintain a continuous dialog
with the people onboard. Constantly
sounding tanks, measuring drafts,
checking conditions of weather, sea
and tide, the crew report to
the RRDA engineers
who input the data
into the model
so that it is
reflective of
reality as they
test remedial
scenarios.
Key to Effective Response
Over the years the RRDA has been called
on an average 14 casualties per year, about
evenly divided between groundings and
collisions or other cases where the hull is
breached – and sometimes, both causes
combined. Because they never know what
to expect, they keep their skills fresh
through frequent drills.
“We work with the operators to simulate
emergency situations,” says Lehrer. “We treat
the drill like the real thing. In fact, because
our job is performed remotely in our Center,
a drill is very much like a real situation. We
know it is different, of course, but physically
we don’t see the difference because in both
cases we are consulting a model and drawings
and simulating responses. So there is, in one
sense, only a small difference between a real
situation, which involves simulating respons-
es, and a drill, which involves simulating
the casualty.”
Altogether, the RRDA team’s involvement
usually lasts about two days, until a salvor
takes over the job. “We assist the salvage
team when they arrive to take over the front
line,” says Lehrer. “Usually, salvors have their
own engineering team as well as a naval
architect on the scene. They typically don’t
have vessel models, and so the first thing they
ask when they arrive on scene is that we give
them the model, the analyses and the salvage
plans we have developed to that point. At
that point our mission is accomplished, unless,
say, they need us to review a lightering or
unloading plan.
“We can transfer all the important data
to them during an emergency because
they all use HECSALV. It is very close to
a universal tool in ship salvage. Likewise,
in cases where the US Coast Guard is
involved, they bring in their SERT (Salvage
Engineering Response Team) division, which
also uses HECSALV.
“It is fascinating work and quite exciting,
although it can also be quite tense because
we have to work very quickly and with
great precision – which is possible because
the modeling response time of HECSALV,
if you know how to handle the program,
is very fast,” he adds. “Stress management
for these situations, however, is another
subject entirely.”
Fernando Lehrer
Marine Service
Technical Manager,
ABS Consulting