Caterpillar 521
Series: Caterpillar Feller Buncher
Caterpillar track feller bunchers 511 to 573 – tracked machines for clear-cutting: the 500 logic, 5x1 and 5x2 for undercarriage and levelling, C7 and C9 ACERT, with Weiler since 2019, 129 to 210 kW
Caterpillar's tracked feller bunchers are the machines of North American clear-cut logging: a saw head with accumulating arms cuts the trees at the stump, holds them in a bunch and lays them down for skidding – on the pine plantations of the South at hundreds of stems per hour. The type logic of the 500 series from LaGrange, Georgia: the hundreds digit 5 stands for the forestry machines, the tens digit orders the size class in ascending order – 511 and 521 the light, 532 to 553 the medium, 563 and 573 the heavy machines with levelling of the upper structure for slopes – and the final digit distinguishes undercarriage and equipment variants. The engines are Cat C7 and C9 ACERT six-cylinders of 8.8 litres, as also power the 320-class excavators. In 2019 Caterpillar sold the purpose-built forestry machines to Weiler of Knoxville, Iowa, which continues the range as Weiler feller bunchers through the Cat dealers.
Read on 3 more paragraphs
The register lists 10 versions with 129 to 210.3 kW from engines of 8,802 cm³ at rated speeds of 1,800 to 2,200 rpm, lengths from 7,614 to 9,424 mm and widths from 2,743 to 3,328 mm.
The tracked feller buncher differs from the wheeled feller in undercarriage and upper structure: it slews 360 degrees, works on slopes where wheeled machines are not permitted and carries saw heads with over 60 cm cutting diameter – the machine for heavy timber and steep terrain.
On used machines, operating hours, the condition of saw head, accumulating arms and saw unit, slew ring and levelling, undercarriage under forestry load and leak-free hydraulics count; parts run through Cat dealers and Weiler.
Sources: Kennwerte der Modelle Caterpillar Fällbündler, Weiler Forestry (Rechtsnachfolger der Caterpillar-Fällbündler seit 2019)
Technical data
Engine
| Engine model | Cat C9 ACERTcorrect |
|---|---|
| Power | 287.9 hp (196.1 kW)correct |
| Rated speed | 2,100 rpmcorrect |
| Displacement | 8,801.5 cm³correct |
| Coolant capacity | 61.3 lcorrect |
| Engine oil capacity | 39.4 lcorrect |
Dimensions and weights
| Length | 8,638correct |
|---|---|
| Width | 3,200.4correct |
| Ground clearance | 69.8correct |
Working data
| Hydraulic oil capacity | 300.2 lcorrect |
|---|---|
| Fuel tank capacity | 530.3 lcorrect |
Other data
| Cab height | 3,557correct |
|---|---|
| System voltage | 24 Vcorrect |
More machines with this engine (Cat C9 ACERT, 8)
Frequently asked questions
How much power does the Caterpillar 521 have?
The Caterpillar 521 delivers 288 hp.
What engine does the Caterpillar 521 have?
8,802 cm³ displacement.
What are the dimensions of the Caterpillar 521?
8,638 mm × 3,200 mm.
What to check before buying
- Check the hour meter against the service records — a replaced instrument is the most common gap.
- Compare the data plate and chassis number with the papers.
- Ask about parts availability for this build year — the running costs hang on it.
A general list for this type of machine — no substitute for an inspection or an appraiser.
We do not sell machines. We ask the dealers who carry this model and come back with price and lead time.
Request a quote →
We ask the suppliers and come back with price and lead time.
Request spare parts →
This page carries 14 individual figures for this model. They come from 1 recorded source; every figure can be traced there. What we cannot document is not here — we leave gaps open rather than estimate them.
Missing a figure you were looking for? Report it →
Know this machine better? Have a photo, a manual, or know that a figure is wrong? Add it to the register →
Other models in this series
Sources: [1]
Forwarder in 3D section
Turn the model, look inside and click an assembly — each one is explained.