With one week to go to the original cut off of the comment
period on the Liquified
Natural Gas (LNG) by Rail notice of proposed rulemaking, the comments that
the DOT’s Pipeline and Hazardous Material Safety Administration will have to
pay attention to in formulating their final rule have started to come in in larger
numbers. I addressed the ones that came in the previous week here.
This week’s batch includes comments from:
Earthjustice
(EJ);
Association
of American Railroads (AAR) and The American Short Line and Regional
Railroad Association (ASLRRA);
Martin
County Board of County Commissioners (MCBCC); and
Indian
River County (IRC)
Lack of Safety Information
A continuing thread seen in comments is the lack of safety
information about the proposed shipments of LNG with many commenters quoting
the NPRM’s comment
that: “It is difficult to estimate the failure rate of the DOT-113 tank car in
derailments because railroads are not required to report incidents to PHMSA or
FRA unless they meet a baseline threshold.”
Fire Hazards
The NASFM comment notes that there is still a fire hazard
from an intact LNG railcar involved in a multicar derailment; stating that: “This
is due to several factors, including the time the product would be in the tanks
while cleanup is conducted, as they would off-gas from those tanks during
cleanup, creating significant hazards.” (pg 2)
The ZFRD comment makes the following comparisons between an
LNG release and a liquified propane gas (LPG) release:
• The flammable range for LNG is
35% greater than LPG;
• A gallon of LNG converts to 625
gallons of vapor, for LPG the number is 270 gallons; and
Asphyxiant Hazard
The NASFM comment raises the issue of LNG being an
asphyxiant hazard as noted in the NPRM. They note that while the AAR OT-55
quoted in the NPRM makes a training containing a single toxic-inhalation hazard
railcar a ‘key train’ that does not apply to asphyxiant hazard containing
railcars.
Sloshing
The EJTF comment notes that since the filling density of LNG
will be limited by the proposed rule to 32.5%, there will be significant free
headspace (they calculate 9.192 gallons) in ‘filled’ railcars which will lead
to sloshing of the liquid while the railcars are in motion. They propose that
this sloshing in multiple railcars in a consist could contribute to derailments.
DOT 113C120 Railcars
The railroad comment notes that there is a task force
(including PHMSA) ‘evaluating the DOT-113 specification for LNG’. Their report
should be available next summer. A separate study that has already been
completed by AAR recommends the following changes to the current 113C120 tank
car standards to improve crash worthiness:
• Increasing the outer tank
thickness from 7/16” (the thickness of a standard DOT-113C120 tank car) to
9/16”;
• Increasing the head from 1/2” to
9/16”;
• Increasing the gross rail load to
286,000-pound; and
• Additional hardening of the
protective housing for valves and fittings.
The comment from Chart Industries corrects a statement about
the LNG railcar in the NPRM. They note that:
“Mylar is a plastic material that
is not compatible with the potential flammable gas being in the annular space.
The common wrapped insulation used in such tanks is often referred to as
Multi-Layer Insulation (MLI), Super Insulation (SI) or Multi Layer Super
Insulation.”
Emergency Response Training
The ZFRD comment notes that:
“Fire departments are not well
trained or equipped to control, extinguish or mitigate a fire involving one or
more LNG tank cars. It is not realistic to think that existing fire department
resources, including response of mutual aid fire departments, can intervene and
mitigate a fire caused by LNG tank cars in a timely manner.”
The comment above was supported by similar comments from IAFF
and IRC.
No comments:
Post a Comment