In early 2020 we tagged 200 containers going out to customers in this region, recorded the base type, and asked those customers to sell them back to us when they were finished rather than to anyone else. Most did. One hundred and seventy-three of the original 200 came home between 2022 and early 2025.
It is not a controlled experiment — different customers, different duties, different care. But it is five Pennsylvania winters of real service, which is worth more than a datasheet.
The results
| Base | Units | Base failed | Rate | Dominant failure | Repairable |
|---|---|---|---|---|---|
| Steel | 68 | 8 | 11.8% | Rust-through at fork pocket | Yes — all 8 repaired |
| Composite | 59 | 14 | 23.7% | Deck cracking at corners | 4 of 14 |
| Plastic (HDPE) | 37 | 7 | 18.9% | Fork pocket cracking | None |
| Wood | 9 | 9 | 100% | Rot, fastener pull-through | None — replaced |
Steel: unglamorous and correct
Steel bases failed least and, crucially, failed repairably. All eight failures were rust perforation at a fork pocket edge, all eight were welded and recoated, and all eight containers are still in service.
The specification sheets tell you steel is heavy and rusts. Both true. What they do not tell you is that a rusted steel base is a Tuesday morning and a cracked composite deck is a new base.
Composite: the surprise
We expected composite to lead. It is the modern default, it balances weight and corrosion resistance, and it is what most current production uses. It had double the failure rate of steel in our sample.
The mechanism is freeze-thaw at the corners. A composite deck is a plastic skin over a steel frame, and water gets into the interface. Five winters of freezing and thawing at that boundary delaminates the corner, then the deck cracks, then it spreads. Eleven of the fourteen composite failures were at a corner and all eleven had been in outdoor service.
Plastic: better than we expected, and unfixable
Plastic bases did well on rate — 19%, between steel and composite — and every single failure was terminal. A cracked HDPE fork pocket cannot be welded, plated or splinted in any way that holds a 2,425 lb load, and we will not sell one that has been.
They are still the right choice in wash-down and food environments where hygiene beats repairability, and they were the best performer of all in the humid mushroom-house service we wrote about in March. But you should buy them knowing that the base is a fuse.
Wood, briefly
All nine wood bases failed within two years and we removed them from the study in 2022. Rot, fastener pull-through, one confirmed case of insect damage. We replace wood bases with steel as a matter of course on any container that comes through this yard, without being asked, and this is the data behind that policy.
What we do with this
- Outdoor duty: steel base, specified explicitly, and we will swap one in if the container arrives with composite.
- Indoor warehouse duty: composite is fine and lighter.
- Wash-down and food: plastic, accepting that the base is a consumable.
- Humid environments: plastic, and expect the cage to fail before the base does.
- Wood: replaced, always, no discussion.
The broader point is that base type is the least-discussed variable in this category and it has a bigger effect on total service life than bottle grade does. Nobody asks about it. Ask about it.