Bulged sump
Stacked bottle-on-bottle, or stored full and double-stacked past rating. Permanent — rebottle.
Logistics — 10 min read
Shipping & stacking IBC totes
Totes fail in predictable ways when they are shipped badly: bulged sumps, popped welds, crushed lower bottles. Every one of those failures traces back to one of five decisions.
- Sheet
- 11
- Revision
- 2026-10
- Scale
- 1:1
- Drawn at
- Peoria IL
A composite IBC is designed to stack on its own cage posts, not on its bottle. Every stacking rule follows from that one sentence.
| Decision | Right way | What happens otherwise |
|---|---|---|
| Stack alignment | Cage post over cage post | Bottle deformation and sump bulge |
| Stack height, empty | 3 high max, aligned | Lower cages rack and twist |
| Stack height, full | 2 high max, rated units only | Creep, then catastrophic failure |
| Securement | 4 straps per row, corner boards | Cage abrasion and strap cut-through |
| Load position | Forward, bulkhead-braced | Shifting and trailer damage |
Rack storage
- Totes belong on pallet racking with full-depth decking or on dedicated tote racks — not on two beams under the pallet edges.
- Check the pallet type before racking. Composite and steel pallets handle beam support; some plastic pallets do not.
- Leave the valve side out. Discovering a weep behind a stack is worse than discovering it in front of one.
- Never rack a tote with bulged walls. Bulging means the bottle has already yielded.
Damage patterns and what caused them
Popped cage weld
Strapped without corner boards, or forklift contact. Repairable on a jig.
Corner crazing
Long-term UV exposure plus flex. Terminal for regulated service.
Cracked pallet runner
Forklift entry at the wrong angle, usually in a hurry. Re-deck.
Weeping valve
Compression-set gasket or grit on the seat. Cheapest repair in the yard.
Caved top
Discharged with the vent closed. The container pulled a vacuum on itself.
The five-minute pre-ship check
- Valve closed, capped, and the cap actually threaded on.
- Top fitting sealed with the correct gasket and the tamper ring intact.
- Cage square, posts aligned, nothing sticking out past the pallet footprint.
- Placard legible, UN marking photographed for the file.
- Four straps per row, corner boards at every cage contact point.
Every common trailer, with what actually fits
| Equipment | Interior height | 275 empty | 275 filled | 330 empty | 330 filled |
|---|---|---|---|---|---|
| 53' dry van | 110 in | 40 / 80 double | 20 | 36 / 72 double | 20 |
| 53' flatbed | n/a | 48 | 20 | 44 | 20 |
| 48' flatbed | n/a | 44 | 18 | 40 | 18 |
| 26' box truck | 96 in | 18 | 8 | 16 | 8 |
| Hotshot trailer | n/a | 8 | 4 | 8 | 4 |
| 20' sea container | 89 in | 18 double | 10 | 9 single | 8 |
| 40' sea container | 89 in | 40 double | 20 | 20 single | 18 |
- Match heights in every stack. Mixing 275s and 330s routes load through the bottle and is the main cause of permanent sump deformation.
- Four straps per row minimum, corner boards wherever a strap crosses galvanised tube.
- Bulkhead forward and load bars every two rows on filled freight.
- Walk the load before leaving and again after the first ten miles. The second walk catches what the first one does not.
- Tarp flatbed loads regardless of weather — it is about road debris and spray as much as rain.
Frequently Asked Questions
How high can I stack IBC totes?
The guide says empty totes can stack 3 high at most, aligned cage post over cage post. Full totes should go 2 high at most, and only rated units. A composite IBC is built to stack on its cage posts, not on its bottle.
How many straps do I need per row?
Use at least four straps per row, with corner boards wherever a strap crosses galvanised tube. Load forward against a bulkhead, and walk the load again after the first ten miles to catch anything that shifted.
How many totes fit on a 53-foot dry van?
The load plan table lists 40 empty 275s single stacked, or 80 double stacked, and 20 filled. Filled loads are limited by weight, not space, since 20 filled 275s of water is about 48,400 lb.
Why is my tote sump bulged?
A bulged sump usually comes from stacking bottle on bottle, or from storing a full tote double stacked past its rating. The guide calls the damage permanent and says the fix is a rebottle. Never rack a tote with bulged walls.
Can I mix 275 and 330 gallon totes in one stack?
No. The guide says to match heights in every stack. Mixing sizes routes the load through the bottle and is the main cause of permanent sump deformation.
Next in the loop
Published 2026-01-08. 10 min read. Written by the crew that does the work, not a content agency.