Delft University of Technology
Faculty Mechanical, Maritime and Materials Engineering
Transport Technology



T.J. Boeschoten Stangengrijper.
Computer program, Report 94.3.TT.4349, Transport Engineering and Logistics.


The 'bar grab excavator' is a type of grab that is used in handling bulk solids. The curve that is travelled by the edge of the grab jaw usually isn't optimal for the fill ratio of the grab. To prevent the fill ratio becoming too low, the crane operator lowers the grab head a little by manipulating the cables. This requires great skill and time to learn.

The programme 'Stangengrijper' calculates the displacements of the cables necessary to realise an arbitrary digging curve making use of a grab of dimensions which are free to choose. Both grab dimensions and digging curve are entered by the user. The digging curve is entered in the shape of ten different points. The displacements of the cables, which correspond to these points, are calculated. Output is created by presenting the results as coordinates and connecting these by means of a line. By doing so one can get a good impression of the relations that exist between grab geometry, desired digging curve and cable displacements.

The programme reads input from the keyboard or from file. Output is presented on the screen (graphics) or is written to a file (numeric output). The programming language is Turbo Pascal 6.0.


Reports on Transport Engineering and Logistics (in Dutch)
Modified: 2008.05.13; logistics@3mE.tudelft.nl , TU Delft / 3mE / TT / LT.