For many years, cargo pump engines on weather decks of Subchapter D & O tank
barges had mechanical-type start and control systems. The installation of
electronically controlled engines on tank barges since the 1990s has
introduced non-approved electrical equipment associated with engine
monitoring and control systems into hazardous locations (Class I, Division
I) on thousands of tank barges nationwide.
U.S. Coast Guard District Eight recognized this problem with John Deere
manufactured engines and distributed enforcement guidance to their field
units on November 22, 2005. Since then, John Deere has engineered retrofit
packages for approximately 400 units and has gained approval from the U.S.
Coast Guard Marine Safety Center for some engine models. Because of
widespread use of electronically controlled engines, we suspect there may be
other equipment currently in use that similarly is not designed or approved
for hazardous locations. Other manufacturers of these engines will likely
need to follow suit with their own retrofit packages.
46 CFR 111.105-31(1) defines Class I / Division 1 locations as any area
located within 10 feet (3 meters) of a cargo tank vent outlet or ullage
opening, or cargo pipe flange or valve on a tank barge that carries a
flammable or combustible cargo with a flashpoint below 60 degrees C (140
degrees F). By regulations, electrical equipment located in hazardous
locations must be approved intrinsically safe, explosion-proof, or purged
and pressurized.
On John Deere electronically controlled cargo pump engines, electrical
ignition sources were found in control panels, notification lights,
alternators, batteries, computers, and associated wiring for engine sensors.
Since new components are still being designed and tested, it may be some
time before all electronic components on John Deere engines can be
re-engineered and retrofitted for hazardous locations. Again, we suspect
other makes of electronically controlled engines have the same issues.
Until complete retrofit packages are designed and approved for these
engines, vessel operators and OCMIs should take immediate steps to eliminate
the risk by ensuring all electrical components on tank barges are in sound
and serviceable condition, and those components that that are not suitable
for hazardous locations are replaced as soon as possible.
