This technical note was written on the outline design of facilities constructed in 1965 for large sized dredging experiment and recently was started to experiment on model bucket of bucket dredger.
　The object of experimental study of this facilities are on the excavative mechanism of bucket, dipper, dragsuction and pump-dredger, and first experimental study is on the study of the bucket's excavative resistance force.
　The purpose of this study are to make clear on the relation among the bucket excavative resistance force, the nature of the soil and bucket's shape to be used, and to design for better effective bucket and quantitatively to express the influence of the nature of the soil.　
　The material to be used are sand, gravel, clay and their mixture which are consolidated by tire-roller. The bucket's shape to be used are the shape of conventional buckets and improved new shape of the buckets.