ISTA Procedures, and other industry-standard packaging test protocols, don’t contain vibration (PSD) profiles for ocean shipment. Several studies have shown that vertical vibration during sea transport is so small that it’s negligible. This is not to say that ocean shipment is benign – there are shocks due to loading and unloading, ship motions can cause the shifting of goods, there is potential damage from extreme temperatures and humidity, and compression forces due to stacking can be large. Since essentially every ocean shipment also involves other kinds of transport (road, rail, air) to and from the port, it has been fairly standard industry practice to simulate those other transport vibrations with the assumption that they envelope any vertical vibration experienced during ocean transport. Regarding shocks related to ocean shipment: there is not a lot of data for loaded sea containers, but what information we have suggests that the shocks are fairly low. The primary shock hazard to ocean-freight packages is probably when they are loaded into the container and unloaded from the container, and are handled at other points during distribution.
The standard practice we see utilized at this time is to select an appropriate test as if the packaged-product were going to be surface-transported only. If you think dockside loading/unloading might be more severe, you could increase the impact velocities and drop heights. You could also add a flat drop or two (to simulate handling with cargo nets), and perhaps some rotational corner drops as well. For stacking, to better simulate the possibly more severe conditions, consider increasing the "F" (compensating) factor above the required value. I'd recommend going to one or more of the atmospheric conditioning extremes (or beyond). You can also consider adding actual water spray to dampen the packages.
Since ocean freight (and air freight) shipment are viewed as less rigorous than the transportation elements experienced when moving in a truck over-the-road. Since everything needs to travel in a truck either to or from the airport/harbor, we recommend testing to account for the truck segment. ISTA 3-series tests are general simulations of the hazards commonly found in a particular supply chain or supply chain leg. The following is a brief explanation of some ISTA tests and the associated supply chain leg…
- ISTA 3A: The single parcel shipping environment (UPS, DHL, FedEx, etc),
- ISTA 3B: The Less-than-Truckload (LTL) environment – typically this is one pallet load or a large individual package that is traveling with other random products from various vendors,
- ISTA 3E: Full truckload – typically unitized pallet loads of goods going from manufacturing to a warehouse or DC,
- ISTA 3F: Mixed load – typically a shorter regional shipment from a DC to the actual store.
The other protocol I would bring to your attention is ISTA 6-Amazon.com-SIOC. This is something to consider if you are doing ecommerce and represents the journey from when a package is received at an Amazon fulfillment center all the way to the end consumers house via either single parcel or LTL. This test combines elements of 3A or 3B depending on the size of the package with other testing elements that represent handling and storage within Amazon.
Utilizing ISTA 4AB to establish a test sequence which includes these additional handling events to your established protocol is another potential path. The ocean freight leg of the journey typically isn’t creating catastrophic failures that are preventable with packaging. However, I do think that the cumulative effects are contributing to the fatigue of a package which then when on land, potential yields failures at a quicker/higher rate. More to come from ISTA on this subject, till then I would love to hear more about your challenges and success with evaluating these hazards against your packaged-products. The real world correlation piece from a variety of product manufactures is always the most useful information in the development & validation of a potential test procedure.
Below are a couple documents talking about the low vertical
vibration levels while on a ship.
- Measurement and Analysis
of Vibration and Temperature Levels in Global Intermodal Container
Shipments on Truck, Rail, and Ship” (Singh et al. 2012)
- “This paper reviews various
previous studies conducted on measurement of physical and climatic
conditions that occur inside International Standard Organization intermodal
containers and their impact on packaging. The study measured vibration
and temperature levels in two different shipments from India to USA where
recorders measured the acceleration levels and temperature data while the
instrumented and loaded containers travelled on truck, rail and ship.
Measured data shows that extreme vibration levels occur while containers
travel on trucks on poor road conditions followed by rail and ship
travel. Highest temperature levels occur inside these containers when they
are stationary and are at dry docks, as opposed to when they are
travelling on truck or rail. Lowest vibration levels and temperature
extremes occur when they are loaded on a ship and are travelling on sea.”
- Measuring the package
shipping environment in refrigerated ocean vessels. Singh, S.P., G.J.
Burgess, J.A. Marcondes, & J.R. Antle (1993) Packaging Technology and
Science, 6(4), 175-181.
- “In summary, the
results from these previous studies show that vibration levels are
different among different modes of transportation, and are generally
higher in truck and rail transport than ship transport.”
- “The vibration and
shock levels were generally very low when the package system was being
transported by ship.”
- “The vertical vibration
produced the highest overall Grms value of 0.209g and represented truck
shipments. Data is presented for all three orientations - lateral,
longitudinal and vertical. Highest results from the vessel or ship were
at 0.127g clearly showing very low level of movement as compared to truck
transport in both continents.”
How can I understand the differences between two ISTA test procedures such as ISTA 6-Amazon.com-SIOC and ISTA 6-Sam's Club for my specific packaged-product?
Unfortunately, ISTA doesn't currently have a test comparison tool so the task will be a manual one. There are a couple ways to tackle this task, Overviews - Compare test overviews from the ista.org webpage. All ISTA Overviews Test Procedures - ...
Which ISTA test should I use?
This common question cannot be answered directly, but must be determined in each case through an understanding of the various ISTA tests and their applications. Please click the following link for more information including a "Test Selection ...
Does the time my package was vibrated in the lab equate to distance traveled in shipment?
The answer to the question of whether a specific vibration test time requires to actual distance traveled in shipping is YES and NO, depending on the test and the shipping means. YES, under certain specific conditions. NO for many common ...
How long are test results valid?
ISTA test protocols should be repeated periodically or as necessary to maintain the quality characteristics of the packaged product on arrival. In addition, tests must be repeated whenever there is a change in the product, the package, or the ...
Who determines pass or fail of testing results?
These determinations are dependent upon the particular product, package, distribution system, market, customers, and other factors and can vary widely. Therefore product damage and allowable package degradation must be defined by the shipper, ...