Choosing the Platform Size for Fish Boxes, Baskets and Samples
Choose a platform that fully supports the base of your largest regular container, with nothing else touching it. Typical European fish boxes measure 600 × 400 mm (10–15 kg fillet boxes), 800 × 400 or 800 × 450 mm (20–40 kg) and up to 885 × 555 mm (50 kg). Measure your own boxes, because rims are larger than bases.
The platform is the part of a scale your containers actually touch, and its size decides whether every box, basket or sample tray sits squarely and safely on the load cells. A platform that is too small lets containers overhang, rest against surrounding structures or slide off on a rolling deck. A platform that is much too large wastes deck space and usually comes with more capacity and coarser readability than you need. This guide lists common fish box footprints, shows how to match them to platform sizes and covers the practical details that catalogues leave out.
The basic sizing rule
Choose a platform on which the base of your largest regular container rests completely, with a little clearance, and on which the container cannot touch anything but the platform. Three reasons stand behind this rule:
- Force shunts. If a box overhangs and its rim touches a wall, rail or neighbouring box, part of the weight bypasses the load cells and the scale under-reads.
- Off-centre loading. A load that is not centred tests the scale's corner performance. OIML R 76-1 requires indications to stay within the maximum permissible errors for different load positions and tests this with a load of one-third of Max on the eccentric segments of the platform. The US requirements for at-sea catch scales in 50 CFR 679, Appendix A include a similar shift test with one-third of capacity in each quadrant.
- Safety at sea. On a rolling deck, a box that overhangs is more likely to tip or slide off. More on load placement at sea in Getting Accurate Weights in Rough Seas.
Measure the base, not the rim. Nestable fish boxes taper, so the outer rim dimension quoted in catalogues is larger than the footprint on the platform. A box listed at 800 × 450 mm stands on a smaller base.
Common fish box footprints
European fish boxes are built around a few recurring footprints. The table uses published dimensions from two European packaging manufacturers, Craemer and Transoplast, as typical examples. Other manufacturers' boxes of the same nominal size can differ by tens of millimetres, so always check your own boxes.
| Box type (fill weight) | Outer dimensions L × W × H (mm) | Volume | Source example |
|---|---|---|---|
| Fillet box, 10 kg | 600 × 400 × 125 | 15 L | Craemer |
| Fillet box, 15 kg | 600 × 400 × 155 | 20 L | Craemer |
| Fish box, 20 kg | 800 × 450 × 190 | 35 L | Craemer |
| Euro fish box, 25 kg | 800 × 400 × 225 | 40 L | Craemer, Transoplast |
| Fish box, 40 kg | 800 × 450 × 270 | 60 L | Craemer, Transoplast |
| Fish box, 50 kg | 813 × 483 × 220 to 885 × 555 × 235 | 70–75 L | Craemer |
The difference between outer and inner dimensions shows how much the walls take up. Transoplast lists its 25 kg box at 800 × 400 mm outside and 670 × 340 mm inside, and its 40 kg box at 800 × 450 mm outside and 645 × 400 mm inside.
Three footprint families cover most boxes: 600 × 400 mm for fillet and small boxes, 800 × 400 to 800 × 450 mm for 20 to 40 kg whole-fish boxes, and about 810–885 × 480–555 mm for 50 kg boxes.
Baskets, trays and samples
Baskets and sampling containers vary far more than fish boxes, so the only reliable approach is to measure what is on board. As general guidance:
- Round or oval baskets used for sorting and subsampling: measure the base diameter and the widest point of the rim, and check that handles cannot rest on a frame or bulkhead.
- Sampling trays and bowls for individual fish and organs: usually fit a small precision platform; choose a tray that sits entirely on it.
- Light samples in the open air: wind load on a large platform or tray becomes a real force at gram level. A small platform with a wind cover is often more useful than a larger one.
- Loose product: a hopper on the scale can be more practical than a container on a flat platform.
WPL platform sizes
WPL marine scales come in fixed platform and capacity combinations. The table lists all platforms with their capacities and the containers they typically suit.
| Model | Platform (mm) | Capacities | Typically suits |
|---|---|---|---|
| M3 120 | 120 × 120 | 300 g, 600 g, 1,500 g, 3,000 g, 6,000 g | Small bowls, organ and stomach samples; wind cover option |
| M3 270 | 270 × 270 | 1,500 g, 3,000 g, 6,000 g | Individual fish, sampling trays |
| M2-S | 300 × 250 | 6 kg, 15 kg | Trays, small containers, packs |
| M2-M | 400 × 300 | 15, 30, 60, 100 kg | Small crates, buckets, 400 × 300 mm containers |
| M2-L | 500 × 400 | 15, 30, 60, 100 kg | Medium crates and baskets |
| M2-XL | 600 × 400 | 30, 60, 100, 200, 400 kg | 600 × 400 mm fillet and Euronorm boxes |
| M2-XXL | 800 × 600 | 60, 100, 200, 400 kg | 800 × 400 and 800 × 450 mm fish boxes, larger baskets |
| M5-S / M6-S | 1000 × 1000 | 600, 1,500, 3,000 kg | Tubs, stacks of boxes, bags |
| M5-M / M6-M | 1200 × 1200 | 600, 1,500, 3,000 kg | 1200 × 800 and 1200 × 1000 mm pallets |
| M5-L / M6-L | 1500 × 1500 | 600, 1,500, 3,000 kg | Large tubs, oversize loads, equipment |
The full readability for each capacity is listed in Capacity vs Readability: Choosing the Right Weighing Range.
Matching containers to platforms
Match the largest regular container to the smallest platform that carries its base completely, then confirm that the capacity and readability suit the load.
| Container | Smallest suitable WPL platform | Capacity note |
|---|---|---|
| Sample bowl or tray up to about 250 mm | M3 270 × 270 | Up to 6,000 g |
| 600 × 400 mm fillet box, 10–15 kg | M2-XL (600 × 400) | 30 kg range allows for tare and ice |
| 800 × 400 mm Euro fish box, 25 kg | M2-XXL (800 × 600) | 60 kg range; XXL starts at 60 kg |
| 800 × 450 mm fish box, 20–40 kg | M2-XXL (800 × 600) | 60 kg range |
| 50 kg fish box, 813–885 mm long | Check base against M2-XXL; otherwise M5/M6-S | M2 100 kg, or platform scale |
| Pallet 1200 × 800 or 1200 × 1000 mm | M5/M6-M (1200 × 1200) | 600 to 3,000 kg |
| Large tub or bag over 1200 mm | M5/M6-L (1500 × 1500) | 600 to 3,000 kg; higher on request for M5 |
Watch for one trade-off in the M2 range: the 800 × 600 mm XXL platform is only available from 60 kg upwards. If you need finer steps for 800 mm boxes than 10–20 g, consider whether the boxes can be weighed with lighter subsamples on a separate scale.
Deck space, working height and handling
A platform that fits the container still has to fit the workflow. Check these points before deciding:
- Free deck or bench space, including room to lift a box on and off without twisting.
- Working height, so that 25 to 45 kg boxes are not lifted from the floor to chest height repeatedly.
- Flow direction: where full boxes arrive from and where weighed boxes go next, for example to a label printer or the hold.
- Trolleys and pallet trucks for heavy loads, which favour a low platform with a ramp.
- Cleaning access underneath and around the platform, so that slime and water do not collect.
- Portability if the scale moves between vessels, laboratories or shore facilities.
Mounting and positioning in detail are covered in Installing a Marine Scale on Deck or in the Fish Hold.
How WPL approaches this
WPL designs its platforms around recurring marine containers. The M2 Series runs from a 300 × 250 mm S platform to an 800 × 600 mm XXL platform and can be fitted with hoppers; S, M and L versions are available with a carrying case. The M3 Series offers 120 × 120 and 270 × 270 mm platforms, with a wind cover for the smaller one. For heavy loads, the M5 Series platform folds up for cleaning and to free deck space, and the M6 Series is available with an access ramp for easy loading. For the complete selection process, return to the buyer's guide.
Frequently asked questions
Can a fish box overhang the scale platform slightly?
A small overhang is acceptable only if the box stands stably, its base is fully supported and nothing touches the overhanging part. In practice, overhang on a moving deck often leads to contact with rails, bulkheads or other boxes, which diverts weight from the load cells. A platform that carries the whole base is the safer choice.
Is a bigger platform less accurate?
Not in itself, but larger platforms usually come with higher capacities and therefore coarser readability. A large platform also collects more water and ice, which shifts the zero, and catches more wind. Choose the smallest platform that supports your containers properly.
What platform suits research sampling at sea?
For individual fish, organs and stomach contents, a small precision platform with fine readability usually works better than a box scale. A 270 × 270 mm platform takes sampling trays and larger individual fish, while a 120 × 120 mm platform with a wind cover suits light samples on an open or draughty deck.
Do 600 × 400 mm boxes fit on an 800 × 600 mm platform?
Yes, and with room to spare, but you would be using a platform that starts at a higher capacity range than a 600 × 400 mm box normally needs. If 600 × 400 mm boxes are your main container, a 600 × 400 mm platform typically gives a better capacity and readability match.
Sources
- OIML R 76-1:2006 Non-automatic weighing instruments, Part 1: Metrological and technical requirements
- US eCFR 50 CFR Part 679, Appendix A: Performance and technical requirements for scales used to weigh fish at sea
- Craemer Group: Fish boxes (dimensions, volumes and fill weights)
- Transoplast: Fish box 25 kg, with drain holes (specification)
- Transoplast: Fish box 40 kg, with drain holes (specification)
Written and reviewed by WPL Industries weighing engineers. Technical and regulatory content is checked against the cited sources. Editorial policy