Application of SKD container transportation solution for excavators

Container transportation offers significant advantages for export shipping. To address the high costs of traditional complete excavator export shipping, we propose using SKD (Semi-Knocked Down) containers to reduce transportation costs. By analyzing the assembly relationships and dimensions of the excavator’s components, we determine the principles for complete machine disassembly (or assembly), select containers, and determine and optimize the disassembly (or assembly) plan. We also design a SKD packing solution using a stacking method to achieve SKD container shipping of excavators.

With the continuous improvement of domestic excavator product technology and brand influence, as well as the cyclical structural adjustments in the domestic industry, exports of complete excavators have gradually increased in recent years. However, the increasing protection policies of governments around the world for domestic enterprises and the localization of production by some domestic manufacturers have reduced the profit margins of complete excavator exports, prompting complete excavator exporters to adopt the SKD (Semi-knocked-down) method of exporting. The importing manufacturer then assembles the complete excavator in the country of origin and sells it, thus achieving localized production and enjoying preferential tax policies.

To ensure the rapid and safe delivery of export products and increase their market share in foreign markets, Chinese excavator exporters must re-evaluate their current methods of shipping complete excavators. Currently, domestic excavator exports mostly utilize traditional methods of shipping complete excavators via bulk carriers or roll-on/roll-off vessels. However, if SKD (Sknitted Goods) excavator exports are to be implemented, container shipping should be considered, as it offers the following advantages over traditional methods:

• Low freight. Container loading and unloading efficiency is high. At the same time, because containers can be stacked in multiple layers, they can save about 10% of ocean freight and port charges compared to traditional transportation methods.
• Safe transportation. Due to the harsh ocean shipping climate, the surface quality of the product can be easily damaged. Compared with traditional whole-machine shipping, the container body forms a solid package, which can effectively reduce the damage caused by moisture, contamination, and theft.
• Shorter shipping cycles. Container ships have high loading and unloading efficiency and are largely unaffected by inclement weather, resulting in shorter shipping cycles than bulk carriers. In summary, shipping excavators in SKD containers offers significant advantages over traditional shipping methods.

Analysis of container size and disassembled machine size

Shipping container specifications

Disassembly and dimensional analysis of the entire machine

Based on the complete machine assembly structure and the actual assembly process, the machine was broken down into SKD components. A packaging plan was then designed based on the specific structure and dimensions of each component. The dimensions of each component are shown in Table 2. It can be seen that, with the exception of the upper and lower frame assemblies, the width dimensions of all other component assemblies meet the packaging requirements.

Selection of containers

Since the weight of the whole machine is 21t, referring to the weight limit requirements of the container, the weight of each component after assembly and packing can meet the requirements, so the weight is no longer considered when designing the packing plan.

Priority is given to designing a packing solution using the smallest number of smaller containers. Considering that the smallest 20″ GP container is only 5.89m in length, and the combined length of all components is much greater than 5.89m, 40″ GP containers are preferred.

Because the upper and lower frame assemblies are extra wide and the welded parts assembly cannot be disassembled, the upper and lower frame assemblies can be placed at a certain angle. The selection of the tilt angle needs to consider the principle that the assembly does not contact the container wall, and at the same time, it must be ensured that it is not too high. Therefore, the upper frame assembly is tilted 36° and the lower frame assembly is tilted 42°. A bracket should be designed to fix it.

Actual application effect

Tianjin Match Machinery Co., Ltd. uses the single-box-per-unit solution described in the article for all SKD parts shipped to Togo, Iran, Russia, Belarus, the Philippines and other countries. This solution is also currently used to pack other types of excavators , as shown in the figure.

Conclusion

The advantages of container transportation and the benefits of exporting excavators as SKD containers have prompted excavator manufacturers to adopt SKD containers for complete machine export, reducing shipping costs. Open-top containers are used for packing, and specially constructed brackets are used to place large components on the upper level, fully utilizing the container’s space. When designing a packing plan, the quality of each component should be considered to ensure balanced overall quality after packing. Of the two options listed in this article, the single-box, single-unit option is superior to the multi-box, multiple-unit option. The centralized packing of all components on a single vehicle facilitates material management during the disassembly, packing, and reassembly processes, thereby ensuring the quality of the finished machine after reassembly.