---
updatedAt: 2025-09-22T12:41:13.000Z
agentTools:
  projectIndex: https://developer.searoutes.com/llms.txt
---

# 𐄷 Weight and containers details

### Best practices for `weight`

#### Key Principles for weight

1. **Direct impact on emissions:**
   * For **road**, **air**, **rail**, and **inland-water**, total shipment weight directly impacts CO₂e emissions. Heavier shipments lead to higher emissions due to the increased energy required for transport.
   * For **sea**, weight affects emissions intensity (kg CO₂e per ton-km) and CO₂e emissions only in case no `nContainers` is provided. The emissions are allocated based on container capacity (dry vs. reefer) and vessel energy consumption.

2. **Default weight assumptions:**
   * If weight is not provided for **FCL** shipments, the system applies a default value of **10 tons per TEU**.
   * If weight is not provided for **parcel** shipments, the system applies a default value of **1 ton**.
   * For `LCL`, no assumptions are made, `weight` is mandatory.

***

### Best practices for `containerSizeTypeCode`

1. **Specify`containerSizeTypeCode` for FCL and LCL shipments:**
   * Use this parameter to reflect the actual size and type of containers transported (e.g., 20GP, 40HC)
   * Accurate container input ensures precise emissions allocation based on TEU capacity and vessel utilization.

2. **Interaction between`weight` and `containerSizeTypeCode`:**
   * When both `weight` and `nContainers` are provided:
     * **`weight`** takes priority for emissions intensity and calculations, except in **sea transport** for FCL orders.
     * **`nContainers`** is used to deduce the number of TEUs, thus emissions allocation in **sea transport**.

3. **Default container size:**
   * If no `containerSizeTypeCode` is provided, the system defaults to **20GP (1 TEU)**.

***

#### Mode-specific considerations

1. **Sea transport:**
   * Total weight has no impact on total emissions when a `nContainers` is passed. Instead, emissions are allocated based on container capacity.
   * Providing accurate `containerSizeTypeCode` ensures proper allocation of vessel emissions.

2. **Road and rail transport:**
   * Weight directly affects total emissions as it determines the energy required for the transport mode.

3. **Air transport:**
   * Weight is a critical parameter that directly influences emissions intensity and calculations.
   * `containerSizeTypeCode` is incompatible with air transport as only parcel orders are supported.