Pultruded FRP corner-cast support for stacked shipping containers. Sized to ISO 1161 standard corner cast, replaces timber dunnage in stack-on-stack stowage, and survives the salt-spray marine cycle across multi-voyage use.
What the buyer is trying to solve
Container-logistics and stevedoring operations.
The buyers who arrive at this page are container logistics operators, terminal operators, and shipping-line procurement. They are evaluating a container-st support column as a replacement for timber dunnage in container-stacking operations - specifically, where stacked containers need a defined support height between the lower corner cast of the upper container and the upper corner cast of the lower container, and the support must be dimensionally stable, weather-resistant, and reusable across multiple voyages. Timber dunnage cracks under load, absorbs water, and must be replaced every voyage; FRP is dimensionally stable, weather-tolerant, and reusable for {{10–20}}+ voyages.
Use cases
Container yard stack-on-stack stowage
Stacking a second container on top of an existing container in the yard, using the support post in lieu of timber dunnage.
01
Vessel hold container support
Inside the vessel hold where the post supports a container above a hatch cover or lashing point.
02
Project-cargo elevated support
Project cargo (heavy machinery, generators) elevated above the container floor to allow forklift access underneath.
03
Loading-dock staging
Temporary support on the loading dock during loading/unloading operations.
04
How the post is used
From ISO corner cast to ISO corner cast.
Lower corner-cast fit
The post's lower spigot seats into the lower container's upper top corner cast (ISO 1161 oval opening).
01
Support height
The post body provides the vertical support height between the lower corner cast and the upper container's lower corner cast.
02
Upper container seat
The upper container's lower corner cast seats onto the post's upper spigot or top plate, depending on geometry.
03
Twist-lock retention
The standard ISO 1161 twist-lock engages with the upper container's corner cast, locking it in place above the post.
04
Removal and reuse
At discharge, the post is removed, stored, and reused on the next voyage.
05
Specifications
|
Corner cast standard |
ISO 1161 standard shipping container corner cast |
|
Standard support heights |
{{100, 150, 200, 250, 300, 400}} mm (verify on first article) |
|
Body section |
Pultruded FRP square section, {{120}} × {{120}} mm standard (verify per project) |
|
Spigot / top plate |
Molded FRP spigot to ISO 1161 oval; steel top plate option for higher load |
|
Resin system |
Vinyl-ester (FR); isophthalic (economy) |
|
Glass reinforcement |
Continuous unidirectional roving + mat, balanced orthogonal |
|
Compressive strength (axial) |
{{verify published value}} MPa (ASTM D695) |
|
Working load |
{{verify per project - typically 8,000–15,000 kg per post}} |
|
UV package |
UV-9 inhibitor integral + UV-stable topcoat for outdoor storage |
|
Salt-spray rating |
No degradation after {{2,000}} h per ASTM B117 |
|
Fire performance |
ASTM E84 Class A on request; ASTM D635 self-extinguishing |
|
Volume resistivity |
> 10⁸ Ω·cm (non-conductive) |
|
Operating temperature |
{{−40}} °C to {{+90}} °C continuous (resin dependent) |
|
Mass per post ({{200}} mm height) |
~ {{2.5}} kg |
|
Color |
Standard safety yellow RAL {{1023}}; grey on request |
|
Design life |
{{10–20}}+ voyages in marine service |
When not to specify FRP container support post
Cases where timber dunnage or steel cradle remains correct.
Three cases where we redirect
- One-voyage short-term use with no reuse plan. If the support is a single-voyage throwaway, commodity timber dunnage is cost-correct. FRP pays back when reused.
- Project cargo above the rated working load. Very heavy project cargo (above {{15,000}} kg per post) requires a steel cradle. Verify on first article.
- Customer mandates ISPM-15 timber dunage for phytosanitary reasons. Some port authorities still require timber dunnage for inbound containers; verify acceptance before switching.
Material comparison
|
Property |
Timber dunage |
Steel cradle |
Enbuss FRP support post |
|
Mass per post ({{200}} mm) |
~ {{3.5}} kg |
~ {{8}} kg |
~ {{2.5}} kg |
|
Voyages per unit |
1–2 (cracks under load) |
{{20–50}}+ |
{{10–20}}+ |
|
Salt-spray cycle |
Swells, cracks |
Rusts |
No degradation |
|
Water absorption |
High |
None |
Low |
|
ISPM-15 required |
Yes |
No |
No |
|
Cost per voyage (normalized) |
Baseline |
~ {{0.6}}× |
~ {{0.5}}× (longer reuse) |
Customization & OEM
Container-logistics customers typically need a project-specific support height and color. Send the project requirement; we return the post drawing and a fixed quote. First article {{6}} weeks; repeat {{3}} weeks.
Frequently asked questions
What is the typical lead time for a {{5,000}} post order?
From PO to first delivery, typically {{6–8}} weeks for standard support heights in vinyl-ester yellow. Custom height adds {{2}} weeks.
Does the post fit ISO 1161 corner cast?
Yes. Spigot geometry is sized to ISO 1161 standard oval opening for 20 ft / 40 ft standard shipping containers. Non-ISO corner-cast geometries verified on first article.
What is the working load?
Project-specific; typically {{8,000–15,000}} kg per post under axial compression. Project engineer evaluates per stack height and stack count.
How many voyages does the post last?
Typical {{10–20}}+ voyages in marine service; verified on first article per project. Visual inspection per voyage; replace on visible crack or fiber exposure.
Is the post stackable for storage when not in use?
Yes. The spigot geometry nests into the body of an identical post; standard 10-post bundle fits a {{1 m²}} footprint.
How is the post inspected in service?
Visual at each voyage; look for surface damage, UV chalking, or impact cracks. Any visible crack or fiber exposure is grounds for replacement.
Is the post recyclable?
FRP can be shredded and used as filler in non-structural concrete. We offer a take-back program in pilot regions.
What documentation comes with each shipment?
Per shipment: dimensional inspection, resin lot certificate, ASTM E84 (if specified), ISO 1161 compliance reference, installation / use guide.
Send your container-stack profile
Send the container corner-cast ISO standard, the stack height, the working load, and the marine service profile. We return a sample post, the published load rating, and a fixed quote.