If the water flow carries heavier materials
(wood, tires, cans, etc.), which is often the case in major urban pumping stations and facilities, the only effective application is automatic grid type E-FAR (Flexible automatic grille).
Flexibility is reflected in the fact that in case of arrival of larger pieces to the grid, a chain with a bucket will draw the piece and move away from the grill and carry the piece to the dumpster or transporter (Sk. 2).