Turnpike challenge
The problem that presented itself to the general contractor, Cone and Graham of Tampa, Florida, was a combination of reach and capacity. Because of existing high tension power lines at each location, the crew had to build four bridges from one side of each canal. The crew had to auger, place and drive half of the pre-stressed concrete foundation piling, as well as form and pour the concrete pier caps and place the heavy deck beams, all from a single side.
Cone & Graham chose to do this with their new 200 ton capacity Link-Belt 248 HYLAB 5 machine which put them close to its working limit. The large (655.5 sq. ft.) footprint with full 166,000 lb five section upper counterweights plus the two piece track counterweights was crucial to the stability of the machine and its ability to reach out 137’ with the 200’ boom. The heavy conventional crawler crane also had to work from thick timber mats because of the soft onsite sand conditions. It was a tricky operation and they were fortunate to have a highly skilled operator to handle the task.
The contract with the FLDOT was to construct four bridges on the Florida Turnpike over two small drainage canals. The Boynton Beach and L-30 canal spanning structures were about 90’ long and 140’ wide. Each pair of bridges is separated by approximately four miles. The jobsite challenges come from the fact that the working space on the job is severely restricted.
The bridges being built in Palm Beach County are for future turnpike widening. The work was done while maintaining both north and southbound traffic.
“I previously had run an LS-248 Link-Belt crane and making the
transition to the Hylab 5 model was a dream. In my opinion the new
machine’s cab is larger and more operator friendly. Its improved
computer system is more accurate and gives the operator a more accurate
depiction of what is actually going on with the load weights, picks,
radii, boom angles and reach. The more comfortable operator’s cab goes a
long way to inspiring greater overall productivity,” said operator Ralph
Holley.
“The improved cab isolation and insulation on the new 248 crane is of significant benefit to the operator when we are driving piling here in South Florida where it is often hot and humid. With the doors and windows closed and the air conditioner going I don’t even need to wear the sound deadening ear muffs like I did in the older machines. A tip of the hat to the Link-Belt engineers for their ergonomic considerations for the operator.”
The operator added that, at the end of the day, he was not near as tired as he was when operating previous conventional cranes. At the age of 62 and after years of experience running cranes, he has had thousands of hours running many different cranes including the Link-Belts, Manitowoc’s, P&H’s and BE’s.
The contractor began the FLDOT contract in December 2004 with
completion scheduled for November 2005. There are four 60’ to 75’ long,
18” X 18” test piles in each bridge. The forty production pilings are
approximately 45’ to 60’ long and driven to a 182 ton bearing. An ICE
8050 diesel hammer was used for this operation. The Link Belt crane was
outfitted with 200’ of straight boom and used an 80’ long set of ICE
swinging leads during the pile driving and deck beam placement. The
FLDOT inspectors said that it was taking an average of 50 to 60 blows
per foot to achieve the designed 182 ton bearing on the 18 inch square
pre-stressed concrete foundation piling. Spacing of the pile varied from
5’8” to 7’10”. An ICE vibratory hammer was used to drive the steel sheet
pile required on the job for cutoff walls.
When working on mats across the narrow 65’ channel in confined working spaces, the 248 H5 at a 105’ radius used a diesel hammer with 80’ long leads weighing about 31,000 lbs. When placing the 90’ by 36” pre-stressed concrete beams over the canal, it was working at a 60’ radius and 73 degree boom angle. The beams weighed around 50,000 pounds.
“Traffic control was one of our major concerns with the limited work space but enforced speed controls with concrete safety barricades and miles of safety barrels solved the problem. We didn’t have any issues. We have good guys who are very safety conscience and we had a safety meeting almost every day,” concluded Randy Cropp, Cone and Graham’s East Coast Division Manager.