Loading Systems

The design of a grab is dictated by the nature of the bulk material that needs to be handled. This guarantees optimal performance of the grab. Other important factors to incorporate in the design process are the grab crane and the conditions at the work site.


Clamshell grab

The Clamshell grab, also known as the four rope grab or the Valstar grab, is one of the most versatile type of grab for every material, providing the material isn’t too coarse.

For a reliable and fast handling of many different bulk goods, Nemag developed the Clamshell grab. This grab enables you to ship practically every kind of bulk material, as long as it isn’t too coarse: coal, ore, minerals, biomass, concentrates, fertilizer, bauxite and phosphates.


The grabs are manufactured from the highest possible quality steels, such as Dillidur 400, Hardox 400, Dillimax 690 and Weldox 700 or equally renowned brands. The clamshell grab’s closing rope guide can be equipped with low friction cable guides, which guarantee a long life span of the closing cables. Standard equipped with low friction pivots, which combine a high lifting power with light and low friction opening and closing of the grab. At your request, we can offer central lubrication.


Characteristics and advantages

The Clamshell grab is available for lifting capacities of over 85 tons and volumes of over 60 m3. Practically every kind of bulk material can be handled providing it is not too coarse. The shells are available in open, half closed and closed versions and with every kind of possible opening direction and with diverse cable patterns. The robust design of the Clamshell grab is manufactured with high-tensile steel. It is lightweight, with excellent filling and digging and fast emptying capabilities. Its also is equipped with excellent cable guides.

The added value of the clamshell grab

  • High free digging productivity
  • Lightweight
  • Specifically suited for handling powdery and dusty material
  • Long life span of closing cables
  • Minimal maintenance costs per ton of handled material
  • Environmental-friendly design