­
1­
MEMORANDUM
SUBJECT:
Inventory
Issues
for
Comment
Related
to
Locomotives
and
Marine
Vessels
FROM:
Locomotive
and
Marine
Rulemaking
Team
Assessment
and
Standards
Division,
Office
of
Transportation
and
Air
Quality
TO:
Environmental
Protection
Agency
(
EPA),
Air
Docket
A­
2000­
03;
E­
DOCKET
OAR­
2003­
0190
DATE:
June
22,
2004
As
part
of
the
development
of
our
NPRM
for
control
of
emissions
from
new
locomotive
engines
and
new
marine
compression­
ignition
engines
less
than
30
liters
per
cylinder,
we
will
be
re­
evaluating
our
marine
diesel
inventory
with
respect
to
Category
1
and
Category
2
marine
diesel
engines
and
locomotives.
We
seek
comment
on
the
following
inputs:

Population
of
Category
2
vessels.
For
U.
S.
flagged
vessels,
population
estimates
were
constructed
from
the
number
of
commercial
ships
greater
than
100
gross
registered
tons
listed
in
Lloyds
Maritime
Information
System
(
LMIS)
database
of
registered
vessels.
Cylinder
displacement
data
were
available
for
about
40
percent
of
the
engines
on
these
vessels,
and
of
those
vessels,
26
percent
were
Category
2
engines.
This
percentage
was
applied
to
all
vessels
in
the
database,
resulting
in
an
estimate
of
1,426
vessels
with
Category
2
propulsion
engines.
An
obvious
concern
with
this
approach
is
that
it
is
not
clear
how
inclusive
LMIS
is,
particularly
for
non­
ocean­
going
vessels.
Also,
the
percentage
of
Category
2
vessels
in
the
LMIS
database
was
derived
based
on
displacement
information
available
for
less
than
half
the
vessels.
It
was
also
assumed
that
all
the
emissions
from
these
vessels
occur
in
the
U.
S.
airshed.
The
contribution
of
foreign
ships
operating
in
U.
S.
waters
was
calculated
in
part
using
cargo
movements
and
waterways
data.

For
Category
2
vessels,
we
seek
comment
on
the
best
approach
for
obtaining
the
population
of
these
vessels
that
operate
in
U.
S.
waters.
Can
better
estimates
be
obtained
for
the
time
spent
within
the
U.
S.
airshed?
Can
reliable
correlations
between
displacement
and
rated
horsepower
be
developed
in
order
to
better
categorize
the
LMIS
database
by
Category?
In
addition,
based
on
previous
work
conducted
in
support
of
the
1999
rulemaking,
foreign
ships
operating
in
U.
S.
waters
contribute
only
a
small
part
(
less
than
5
percent)
of
the
total
inventory
for
these
vessels.
How
can
this
be
confirmed?

Growth
rate
for
Category
2
vessels.
In
the
supporting
analysis
for
the
1999
rulemaking,
an
annual
growth
rate
of
2
percent
was
estimated
based
on
production
and
turnover
in
several
recent
years.
We
instead
opted
to
use
a
more
conservative
growth
rate
of
1
percent
that
is
more
consistent
with
the
Category
1
growth
estimates.
What
is
an
appropriate
growth
rate
for
these
vessels?
­
2­
Auxiliary
engine
population,
size,
and
use
on
Category
2
and
Category
3
vessels.
For
the
1999
rulemaking,
assumptions
were
made
regarding
the
number
of
auxiliary
engines
used
on
Category
2
and
Category
3
propulsion
vessels.
We
seek
comment
on
how
many
auxilary
engines
are
typically
used
on
Category
2
and
Category
3
propulsion
vessels,
and
their
rated
horsepower
or
displacement.

Spatial
allocation
for
Category
1
and
Category
2
vessels.
For
Category
1
and
Category
2
vessels,
we
only
developed
national
estimates
of
emissions.
No
geographic
allocation
was
done.
For
Category
3
vessels,
inventory
estimates
were
developed
separately
for
vessel
traffic
within
25
nautical
miles
of
port
areas
(
called
"
in­
port"
emissions)
and
vessel
traffic
outside
of
port
areas
but
within
175
nautical
miles
of
the
coastline
(
called
"
non­
port"
emissions).
The
in­
port
emissions
were
estimated
for
120
commercial
ports,
so
these
can
easily
be
allocated
geographically.
The
non­
port
estimate
was
a
national
total
and
was
not
allocated
geographically.

We
seek
comment
on
a
number
of
issues
related
to
emissions
allocation
for
Category
1
and
Category
2
vessels:

S
Is
it
valid
to
assume
that
all
Category
1
vessels
will
be
operated
in­
ports?
How
should
they
be
distributed
among
the
120
commercial
ports?

S
What
is
the
best
approach
to
distribute
the
national
Category
2
emissions
to
inport
and
non­
port
areas?
Can
some
ratio
to
Category
3
vessels
be
used?

S
What
is
the
best
approach
to
allocate
non­
port
emissions
to
the
county
level?
Currently,
EPA's
National
Emissions
Inventory
(
NEI)
allocates
non­
port
emissions
to
the
county
level
by
applying
county­
specific
waterway
activity
factors,
expressed
as
thousand
ton
miles.
Can
this
methodology
be
improved?

S
Are
the
boundaries
for
in­
port
(
25
nautical
miles)
and
non­
port
(
from
port
boundary
to
175
nautical
miles
from
shore)
appropriate?

Effect
of
grade
and
elevation
on
locomotive
emissions.
The
current
emission
factors
used
in
the
1997
rulemaking
do
not
account
for
grade
or
elevation.
We
seek
comment
on
the
availability
of
adjustment
factors
that
could
be
applied
to
the
available
emission
factors
to
account
for
these
effects.

Growth
rate
for
locomotives.
We
seek
comment
on
the
use
of
railroad
distillate
fuel
consumption
data
as
a
reliable
indicator
of
locomotive
growth.
Are
fuel
or
other
data
available
to
develop
growth
rates
by
category?

Contribution
of
steam
locomotives.
Steam
locomotives
are
typically
not
included
in
emission
inventory
estimates,
as
the
population
is
believed
to
be
very
small.
How
can
we
confirm
this?

Spatial
allocation
for
locomotives.
In
the
1997
rulemaking,
only
national
estimates
were
derived.
No
geographic
allocation
was
done.
EPA's
NEI
allocates
locomotive
emissions
to
the
­
3­
county
level
using
county­
specific
railroad
traffic
data
(
in
ton
miles)
from
DOT.
County
borders
are
then
overlaid
with
the
U.
S.
railroad
network
to
determine
rail
activity
in
each
county.
Emissions
for
the
switch
(
also
known
as
yard)
category
were
spatially
allocated
to
urban
counties
which
had
Class
I
railroad
activity.

Can
we
improve
on
the
methodology
used
in
the
NEI?
In
particular,
are
there
countylevel
usage
data
for
switch,
commuter,
and
other
categories
of
locomotives?

Comments
may
be
submitted
by
one
of
the
methods
specified
in
the
ANPRM.
