A wingbox is a three-axle tronton truck whose side walls swing up, so pallets can be loaded from the side by forklift. A box truck loads only through its rear doors, while a trailer chassis carries a 20' or 40' container or cargo on an open flatbed. The right choice depends on the shape of the load, how your warehouse loads and unloads, and the road classes along the route.
Wingbox, box and trailer at a glance
The figures below are typical Indonesian catalogue values. Replace them with the numbers in the KIR book and STNK of the unit you actually hire.
| Vehicle | Deck L × W (mm) | Internal height (mm) | Volume | Payload (kg) | Loading access |
|---|---|---|---|---|---|
| Tronton box | 9,000 × 2,400 | 2,400 | 51.84 m³ | 15,000 | Rear doors |
| Wingbox (tronton) | 9,400 × 2,400 | 2,500 | 56.40 m³ | 15,000 | Both sides + rear |
| 20' container chassis | 20' box (5,898 × 2,352) | 2,393 | 33.2 m³ | 24,000 | Container doors |
| 40' container chassis | 40' box (12,032 × 2,352) | 2,393 | 67.7 m³ | 26,000 | Container doors |
| 40 ft flatbed | 12,200 × 2,450 | open | deck 29.89 m² | 28,000 | Top and sides (crane/forklift) |
For trailers, ask whether the payload a haulier quotes includes the container's own tare weight. A surprising number of disputes start right there.
The wingbox: why side loading matters
A wingbox truck changes how a dock works. With a box truck, the forklift has to drive into the body, or pallets are pushed in from the rear with a pallet jack, which needs manoeuvring space and time. With a wingbox:
- two forklifts can work from the left and right simultaneously;
- pallets can be set tight against the headboard and each other, with no space left for equipment;
- multi-drop deliveries are easier because any pallet can be lifted out from the side;
- long items such as pipes or aluminium profiles slide in far more easily.
The trade-off is weight: the wing mechanism and frame make the body heavier than a plain box, so effective payload can be a little lower. Hinges and wing seals also need upkeep to stay watertight.
Pallet counts on a wingbox deck
The counts below assume a 9,400 × 2,400 mm deck, a single layer and zero clearance (theoretical).
| Pallet | Best pattern | Count | If internal width is 2,390 mm |
|---|---|---|---|
| 1200 × 1000 mm | 9 rows crosswise (1,200 across) × 2 | 18 | 15 |
| EUR 1200 × 800 mm | 1 row of 3 lengthwise + 10 rows of 2 crosswise | 23 | 15 |
| 1100 × 1100 mm | 8 rows × 2 | 16 | 16 |
The last column is the important one. The 18-pallet pattern only works if two 1,200 mm sides sit side by side, which needs the full 2,400 mm. If the body really measures 2,390 mm, the pallets must turn lengthwise (7 rows of 2) plus one pallet at the end, giving 15. The 1100 × 1100 pallet is unaffected because two of them only take 2,200 mm. So measure the internal width at its narrowest point, including posts and wing rails, before promising a pallet count to a customer.
For comparison, a 40 ft container theoretically takes 22 pallets of 1200 × 1000 (20–21 in practice) and 25 EUR pallets (23–24 in practice). See our guide on how many pallets fit in a container.
Container trailers: drayage to and from the port
A container trailer is a tractor head plus a chassis with twistlocks at the corners. Moving boxes between port, depot and warehouse is called drayage or container trucking. Points to watch:
- Container gross weight. A 20' can carry up to 28,250 kg of cargo (30,480 kg maximum gross), but the truck combination often reaches its road limit first.
- Heavy 20s. A dense 20' concentrates weight over particular axles; where it sits on the chassis changes the axle loads.
- 40s. Lighter per metre, but the combination is long, which means Class I roads and room to turn at the warehouse.
- Flatbeds. For goods that will not fit a container, such as machinery or long steel; the load must be secured following cargo lashing and securing practice.
Road class limits that matter
Under Law 22/2009, the road class sets the dimensions and the heaviest single-axle load (MST) that may use it.
| Road class | Max width | Max length | Max height | MST |
|---|---|---|---|---|
| Class I | 2,500 mm | 18,000 mm | 4,200 mm | 10 t |
| Class II | 2,500 mm | 12,000 mm | 4,200 mm | 8 t |
| Class III | 2,100 mm | 9,000 mm | 3,500 mm | 8 t |
| Special class | > 2,500 mm | > 18,000 mm | 4,200 mm | > 10 t |
A catalogue wingbox at about 11,900 mm overall stays under 12,000 mm, but its 2,500 mm width rules out Class III roads. A 40' combination of about 16,500 mm belongs on Class I roads only. Always check the road class signs on the route, including access roads.
Worked example
A factory in Cikarang ships 18 pallets of 1200 × 1000 mm, 1,400 mm high, 780 kg each (pallet included), to a distributor in Semarang.
- Total weight: 18 × 780 = 14,040 kg, or 93.6% of the wingbox's 15,000 kg payload.
- Volume: 18 × 1.2 × 1.0 × 1.4 = 30.24 m³; floor used 21.6 m² of 22.56 m² (about 96%).
- Condition: the wingbox must genuinely measure at least 2,400 mm inside. At 2,390 mm only 15 pallets go, and the other 3 need another vehicle.
- Double stacking is out: 2 × 1,400 = 2,800 mm exceeds the 2,500 mm internal height, and 36 pallets would be far over payload anyway.
Now compare an export 20' holding 22,000 kg of cargo. The container's gross weight is 22,000 + 2,230 = 24,230 kg. That is fine for the box (30,480 kg maximum) but 230 kg over the catalogue payload of a 20' chassis (24,000 kg) if that figure includes container tare. In cases like this the truck and the road, not the container, set the limit.
Common mistakes
- Promising 18 pallets without measuring the width. A 10 mm shortfall can cost three pallets.
- Equating chassis payload with container payload. They are different limits.
- Booking a 40' trailer for a warehouse on a Class II or III road. The truck may be stopped or the load transferred to smaller vehicles.
- Leaving pallets unsecured in a wingbox. The wings are not load restraints; use straps or blocking so pallets cannot slide under braking.
- Putting the heaviest pallets at the very rear. Weight distribution still matters for the steer axle.
Plan the load with the right tools
Start with the truck finder to compare wingbox, box and trailer options by volume and weight. For pallets, check the floor pattern with the pallets per container calculator, then build the load in the Load Planner using the real body dimensions. For an overview of every class, see Indonesian truck sizes. A plan is a simulation; official weights still come from the weighbridge and the operator's approval.