The John Deere FD55 head has been designed to be more versatile for different tree diameters.The FD55 felling head is compatible with the John Deere 643K and 843K wheeled feller bunchers. It is ideal for full tree logging operations from thinning through to clearfelling. It features improved visibility to the cutting zone, high accumulation capacity and the ability to fell trees up to 58.4 cm (23 in) in diameter. The FD55 has a tall horn structure for more control and stability when harvesting larger trees.
Accumulation capacity is increased through an innovative pocket design that has an area of 0.63 m2 (6.8 ft2). The head has one harvesting arm and one accumulating arm. Tree handling and placement are improved through the strong grab arm force. Tight tree alignment takes place and the bunch is released cleanly. Visibility has been increased by the use of a compact and streamlined design which allows the operator to see around the saw motor to the cutting zone. Visibility is also maintained by the prevention of debris due to a sloped angle on the top of the head. Source: www.deere.com/en_US/newsroom/forestry_all.html