The Northwest corridor project for the Georgia DOT consists of constructing managed reversible toll lanes from the intersection of I-75 and I-285 on the north side of Atlanta. The two lanes are primarily on the west side of the existing interstate up to the split of I-575 and I-75, where one lane will continue up I-575 and the median and another lane up I-75. These are manageable reversible toll lanes, in the morning they will be traveling southbound and northbound in the evening.
On site, Northwest currently utilizes five Kobelco crawler cranes: three 110-ton CK1100Gs and two 160-ton CK1600Gs. A sixth 275-ton Kobelco CK2750G is ready to be delivered to the job site. Depending on location and job type, the boom lengths typically average 110 to 130 ft. for the CK1100Gs, and 150 ft. on the CK1600Gs.
The CK1100G has a maximum boom length of 200 ft. and maximum fixed jib combination of 190 ft. plus 60 ft. The CK1600G has a maximum boom length of 250 ft., and maximum fixed jib combination of 200 ft. plus 100 ft., and maximum luffing jib length of crane boom 157 ft. + luffing of 175 ft. The Kobelco cranes' performance can be monitored daily in the Northwest Express Roadbuilders office through the standard KCROSS telematics system. Also aiding operator efficiency on the job are features such as large LMI displays with color touchscreens, and dial-type line speed controls. Job site safety is aided by standard swing limiters and control lever lock outs.
The cranes will be constructing 43 bridges on the job site. In the beginning, the Kobelco crawlers were used primarily for foundation work and pile driving. As of now, they are assisting with the erecting of bends and beam settings, and they also will be assisting with the bridge decks.
Some of the precast bridge girders were set initially with the CK1100G and CK1600G dual lifting, the girders weighing around 48,000 lbs. The CK2750G will be brought in to help in erecting bridge segments. Moving forward, Northwest Express has other hydraulic cranes that will be assisting as well because the beams weigh closer to 88,000 lbs. Girders are a mix of precast and steel.
The time frame of this project is scheduled for completion in 40 construction months.
Source: Lift & Access Magazine