Flexitank steps on rail
EPT's unit passes rigorous testing at AAR test site in Pueblo, Colo.
By Chris Gillis
For more than 30 years, flexitanks have allowed shippers of bulk liquid products to enjoy the benefits of containerized ocean freight transportation, but not the related rail intermodal services.
North American railroads in recent years have refused to move loaded flexitanks in containers because they have been known to rupture and leak due to the punishing motion of the trains.
This changed for one provider late last year when it announced that its flexitank passed both of the Association of American Railroad's rigorous rail impact and simulation tests ' an industry first.
'The tests are recognized by the AAR and the rail industry as benchmarks for high performance standards that are required to ship via rail in North America,' said Nancy Wendrock, president of Houston-based Environmental Packaging Technologies (EPT), in a statement.
Wendrock noted that the AAR does not officially approve or endorse any company's flexitank. 'A company either passes or does not pass,' she said. 'This gives the flexitank operator the opportunity to approach individual North American railroads, to secure approval on their rails. EPT is currently working with and is approved by several rail companies.'
EPT spent more than a year re-engineering its flexitank, dubbed the BIG Red, before submitting it to the rail impact test, which took place at AAR's Transportation Technology Center in Pueblo, Colo., on April 28, followed by the rail simulation test on June 27.
The rail impact test parameters included:
' Ensuring a loaded flexitank could withstand the force of multiple impacts, the type routinely experienced during rail transport.
' Conducting the test in a 20-foot container, which satisfied test criteria required by the Container Owners Association, an international trade group.
| A diagram of the BIG Red flexitank |
For the flexitank to successfully pass the test, it must show no signs of leakage, maintain an intact bulkhead, and allow minimal sidewall and end-wall deformation. The flexitank's bottom valve and bulkhead must also not come in contact with the closed container doors.
'Tests conclusively showed that the bulkhead securement system, and flexitank, successfully passed with flying colors,' Wendrock said. 'There was no bulkhead movement.'
During the rail simulation test, the AAR subjected EPT's flexitank to a series of impacts and vibrations that simulated more than 260 miles of travel over all classes of rail at accompanying speeds. 'There was no movement nor deflection of the bulkhead and no permanent deflection of the container walls,' Wendrock said.
For its flexitank, EPT designed a rail 'swept-bar' bulkhead system to replace the market's traditional flexitank bulkhead barrier, which prevents the tank from hitting the container doors.
In September at Canadian National's rail facility in Toronto, EPT completed a series of terminal handling maneuvers devised to measure the effect of liquid dynamics and G-force on the flexitank and rail handling equipment.
'Out of the testing came new safety standards and a criteria for accepting flexitanks on rail,' Wendrock said. She added that the CN's concern for safety of both personnel and equipment helped EPT to further raise its performance levels. EPT is working with CN to implement these standards.
The flexitank has come a long way since its earliest days in the mid-1970s when U.K. shippers began experimenting with moving liquids in heavy duty rubberized bladders to South Africa and Australia. The tanks were expensive, about $5,000 apiece, but they were marketed as reusable, explained Roger Goose, EPT's vice president of logistics, in an interview.
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| Goose |
In the early 1990s, the rubber tanks were replaced with those made of thermo-plastic (PVC) materials. The tanks became much cheaper, retailing to shippers for about $1,850 each.
Chemical shippers became the earliest users of flexitanks for the transport of non-hazardous liquid shipments. However, these shippers generally didn't like the task of fitting the tanks into the containers. Companies that sold flexitanks started offering 'supply and fit' services.
Chemical shippers also became more interested in flexitanks because of their much lower tare weight compared to a containerload of filled metal drums. A 20-foot container can handle 80 drums of about 4,400 gallons, compared to 6,000 gallons in a containerized flexitank. In addition, the disposal of the drums had become an increasingly high-profile environmental issue for chemical companies.
In late 2001 newer and cheaper flexitanks made from multiple layers of thin polyethylene entered the market. 'Now flexitank transport has truly become a one-way, disposable market,' Goose said.
Goose, a 30-year flexitank industry veteran, said many flexitanks today are made cheaply overseas and quality is sometimes questionable.
EPT manufactures the BIG Red flexitanks in its Michigan plant, taking advantage of high-tech automotive technology. In addition to the improved quality control, EPT officials said manufacturing costs went down by 25 percent to 30 percent compared to sourcing from overseas.
Flexitanks are still only used for transporting non-hazardous liquid commodities. EPT's clients include Georgia Pacific, DB Schenker, Conoco Phillips, Genencor, Gavilon (formerly ConAgra) and Exxon Mobile. Products often shipped in flexitanks include food additives, vegetable oils, latex, and lube and pharmaceutical grade mineral oils.
One of the fastest growing segments of flexitank users are wine shippers. The flexitank offers them a cost-effective alternative to shipping cased goods or intermediate bulk containers, Goose explained.
Bob Bruns, president of Lodi, Calif.-based JIB International, a freight forwarder that specializes in the overseas transport of California wines, called EPT's BIG Red flexitank a 'breakthrough,' providing his clients an option to take advantage of intermodal services to East Coast ports to connect with transatlantic liner services to Europe. 'Right now, all-water service into Europe from the West Coast is just not good,' he said.
Bruns hopes companies like EPT will continue to develop their flexitank capabilities and shipper offerings.
'As a forwarder, I would like to see some innovations in less-than-containerload flexitanks,' he said. 'I get calls all the time from wineries who want to send some bulk wine overseas, but at less than 500 gallons and without the cost of barreling. A flexi-alternative like that would be great.'