Caterpillar uses advanced engineering and software to analyze
all structures, creating a durable, reliable machine for the
toughest applications. More than 70 percent of the structural
welds are robotic and achieve additional penetration over manual
welds. These structural components and undercarriage are the
backbone of the machine’s durability.
Carbody Design
X-shaped, box section carbody provides excellent resistance
to torsional bending. Robot-welded track roller frames are
press-formed, pentagonal units that deliver exceptional strength
and service life. Idler and center guards help maintain track
alignment when traveling or working on slopes.
Grease Lubricated Track
Grease lubricated track protects the track link, delivers long track
pin and bushing inner wear and reduces sound levels.
Travel Motors
Travel motors with automatic speed selection let the 311D LRR
automatically change up and down from high and low speeds
in a smooth controlled manner.
Undercarriage and Structures
Strong, stable and easy to maneuver
Front Linkage
Reliable, durable and versatile
Built for performance and long service life, Cat booms and
sticks are welded, box-section structures with thick multi-
plate high strength steel fabrications. Service intervals are
extended with self-lubricating bearings that resist corrosion
and galling for superior durability.
Boom
The boom is designed for maximum digging capability and
is robotic welded to ensure consistent quality. This allows
excellent all-around versatility and a large working envelope.
Stick
Three stick options are available to meet your application
needs and increase performance and productivity. A new
2.6 m (8'6") intermediate stick is available to provide long
reach and increased digging and lifting capability.
