New Products - Caterpillar SH-56B disc saw felling head

The SH-56B is a high capacity bunching saw designed to be matched to the new Cat C Series wheeled feller bunchers.

The head has been designed to work in first and second thinning operations, either handling high volumes of small stems, mixed stems or large single stems. It has a larger accumulation pocket to allow smaller trees to be handled, but can still fell large trees of up to 56 cm (22 in).

Durability is the key word used by Caterpillar to describe the new head. The head is more than 270 kg (600 lb) heavier than its predecessors (the SH-50 and SH-56). Caterpillar has been able to produce a heavier (and more robust) head due to the improved stability of the carrier (C Series wheeled feller buncher). As discussed in the Oct 2 issue of Logging-on, this better stability was achieved by placing the engine at the back of the machine, resulting in better weight distribution and balance between the front and rear axles. Some of the key features of the new felling head are as follows:
 

• Tapered roller bearings – the bearings are found in both the upper and lower high cycle pin joints of the gathering arm and bunching finger. This reduces impacts from shock loads on the hydraulic system and head structure.
• Abrasion-resistant materials – these materials are found in the saw housing, carry plate and discharge chute structures. An additional layer of replaceable abrasion-resistant material reinforces areas that take the most wear.
• Saw base – the SH-56B has a larger diameter disc than previous models, allowing it to cut trees of up to 56 cm (22 in), compared to 51 cm (20 in) previously. The overall width of the head has not changed. The disc is also extended out further from the frame than previous models, allowing more reach in thinning operations. This also created space for a more substantial structure in the base to support the gather arm cylinder. A larger discharge chute removes chips and debris quicker, resulting in less wear and improved disc recovery time, which reduces fuel consumption.
• Gather arms – the saw has a bunching capacity of 0.69 m2 (7.4 ft2). The large torque tube design of the gather arm enables higher loads to be supported without bending the gather arm. The gather arm also has a flared lower joint that can better withstand forces.
• Strait Grip finger – this bunching finger tucks trees into the accumulating pocket, while keeping tree tops together and creating tighter bunches. When the tree tops are kept together, larger loads can be accumulated before placing the trees onto the ground. This is particularly important in thinning operations.
• Tower – the 272 cm (107 in) box section design tower provides good stem control, while the twin tower frame gives the operator direct-line visibility.
   

The SH-56B can be attached to all new C Series feller buncher models, as well as Cat 563C, Cat 573C, Prentice 2570C and Prentice 2670C wheeled feller bunchers. The key specifications are included in the table below.