Manitowoc Modernizes Model 999 Lattice Boom Crawler Crane, Christens It The MLC250
Manitowoc has updated its venerable, 275-ton (250-metric-ton) model 999 lattice boom crawler inside and out. Although the crane retains its 290-foot (88.4-meter) boom length and load charts, the changes bring it in line with the company’s MLC series. Hence, it only made sense to align its model number as well. The new MLC250 is designed for use in the infrastructure, refinery, and commercial building industries.
“The Model 999 has been a firm favorite with contractors in the heavy construction and energy sectors for 20 years, providing enough reach and capacity to tackle virtually any job,” says Manitowoc Cranes Product Manager Brennan Seeliger. “Feedback received through our Voice of the Customer new-product development process showed that users were still satisfied with its performance, but there were areas that could be enhanced to bring it in line with our newer crawlers. Following a wide range of updates, it seemed only logical to move the 999 into the MLC lineup, which shares many of those same features.”
Efficiency Upgrades
Manitowoc changed the crane’s hydraulics system from a closed-loop configuration to an open-loop system for more responsiveness, greater efficiency, better performance, and easier cold-weather starts. Instead of a number of pumps constantly requiring power (parasitic load), two main pumps are now responsible for all primary functions aside from swing.
The MLC250 still uses the 999’s time-tested Cummins QSL9 diesel engine, but it’s been upgraded to meet EU Stage V and U.S. EPA Tier 4 Final emissions regulations. The motor’s power level has been tweaked to a more efficient 340 horsepower (254 kilowatts) at 2,100 rpm.
The new crane shares components in common with a variety of Manitowoc models old and new, maintaining its appeal to fleet owners. An 80-ft (24.4-m) fixed jib and a 240-ft (73-m) luffing jib are also available for the new crane.
The MLC250’s standard tracks have a 48-inch (1,219-millimeter) shoe width, with 60-in. (1,524-mm)-wide tracks available for lower ground pressure and greater stability. Manitowoc relocated the crane’s crawler drive motor from the carrier to the tumbler to increase its performance.
Easier To Control
The new crane has a wider cab than the 999, with an optional hydraulic tilt capability of up to 20 degrees. Another option is the Manitowoc Vision Cab, as seen on the MLC300 and MLC650 crawlers.
The MLC 250 also gets a usability upgrade to Manitowoc’s Crane Control System (CCS), which replaces the 999’s EPIC control system. The CCS features electronic joysticks, a color display, a jog dial for on-screen navigation, and user-adjustable speed settings for all crane movements.
Better Service Access
Manitowoc also took the opportunity to improve the MLC250’s access to its service compartments. The 999’s fiberglass gull-wing enclosure doors have been replaced by swing-open steel doors, as on the MLC100 and MLC150.
Also, instead of the 999’s pivoting walkways, service personnel can now walk on the more stable carbody counterweights as part of the upper deck. New steps on the undercarriage offer easier access to the upper platform.
Source: Manitowoc