
Kobelco’s new SK400DLC-10 and SK550DLC-10 excavators are designed for tearing down buildings eight to nine stories high.
The crawler excavators can be configured four different ways through a joint system starting at the common base boom for three reach lengths and for digging.
For demolition of lower levels, the attached separate boom has a working height up to 48 feet for the SK550D and 45 feet for the SK400D.
When needing extra height, the ultra-long attachment can be added to achieve 81 feet of reach for the SK400D and 90 feet for the SK550D. The height can be shortened on the attachment by about 10 feet by removing the boom insert, when you don’t need maximum height but need more than the separate-boom height.
For digging, the excavators can reach a depth of about 20.5 feet with the separate boom. The excavators can be equipped with crushing tools up to 5.3 tons on the separate boom and up to 3 tons on the ultra-long attachment.

Kobelco designed the boom system for quick assembly and teardown. The boom attachment is connected by hooking the upper pin and then fixing the separate opposing pins on the lower side. The boom attachment joints have hydraulic quick-coupler connections mounted on the side.
The ultra-long attachment has a storage and transport height of just 7 feet 3 inches. Also to help transport, crawler width can be retracted at the push of a button to 9 feet 9 inches, and the counterweight can be separated into two parts.
For reducing silica dust, Kobelco made water suppression standard, with plumbing for the system from the base to the ends of the separate boom and high-reach fronts.
For fuel economy, the company added auto-idle and an ECO mode. The excavators also have an “S” mode to balance between work volume and fuel consumption, and an “H” mode for high work volume.
Aiding the operator
For operator safety, a cab interference-prevention system was included as standard. The feature sounds an alarm when the attachment tool gets too close to the cab, and it automatically prevents the attachment from hitting the cab. It detects the tool’s position, so it can create a safe working range for the attachment, the company says. Operators can program multiple tools into the system.
For working at heights, the cab can be tilted up as much as 30 degrees to reduce operator fatigue. An emergency cab-lowering device is included, and a crosspiece on the right side window was added for additional operator safety.
Other standard features include rearview and right side cameras; boom, arm and jib holding valves to prevent the boom or arm from falling if a hose is damaged; two LED lights on the cab top; and a falling-object detector on the ultra-long attachment to deflect falling debris from the machine.
Full track guides prevent crawler de-tracking, including when traversing demolition rubble, the company says. Kobelco added thick upper-frame belly guards, a swivel guard, travel motor guard and cylinder guards to protect components from debris.
An auto-lubrication system automatically greases the upper body at specific times. The excavators also come with the Kobelco Monitoring Excavation System (KOMEXS) telematics.
Quick specs
SK400DLC-10 SK550DLC-10
286 hp 363 hp Power
750 lb.-ft. 1,084 lb.-ft. Max torque
103,200 lbs. 132,500 lbs. Operating weight
12.7 psi 14.9 psi Ground pressure