TOTE Maritime Puerto Rico (TMPR) has leased 220 NaturaLINE reefer units through SeaCube Containers in an effort to enhance its fleet with the industry’s only natural refrigerant-based system from Carrier Transicold.
TMPR is the first shipping line to place a sizeable quantity of NaturaLINE units into service on US domestic trade routes.
The units use carbon dioxide, a refrigerant with the lowest global warming potential (GWP) among all refrigerants currently used in container systems.
The reefers – a mix of 40 ft and 45 ft high-cube models – use CO2 refrigerant, also known as R-744, which as a GWP of 1 in comparison to GWPs that range from 600 to nearly 4,000 for refrigerants used in other container systems.
R-744 is non-ozone depleting, widely available, relatively inexpensive and classified as A1 for low-toxicity and no flame propagation, noted a statement from the refrigerated container manufacturer.
David Appel, president of Carrier Transicold and Refrigeration Systems, said: “With its natural refrigerant, NaturaLINE units help fleets guard against regulations, environmental taxes and phase outs that other refrigerants could be subject to during the operational life span of units purchased today.”
R-744’s thermal characteristics enable the energy-efficient NaturaLINE unit to achieve -40 degrees Celsius, along with significantly quieter operation, tighter temperature control and with no operating restrictions.
Previously, reaching such a low temperature required a container system using a refrigerant with a GWP nearly 4,000 times higher than R-744.
Jim Wagstaff, vice president operations, TOTE Maritime Puerto Rico, said: “TMPR tested NaturaLINE units in our fleet and found that in all temperature ranges, its capabilities surpassed our expectations.”
The NaturaLINE unit’s deep-frozen capacity was an important factor for TMPR when considering moving cargoes, such as ice cream, through the tropics because of the high level of performance required to ensure optimal conditions.
Since 2015, TMPR has used emissions-reducing Marlin-class vessels, the first containerships efficiently powered by liquefied natural gas (LNG).