Tasked with a major upgrade of the iconic Palm Beach Town Marina, Murray Logan Construction (MLC) was faced with a challenge: finding the best way to accurately, but efficiently, excavate the floor of the marina basin in order to accommodate larger vessels. This challenge was met with through the adoption and application of GPS-based machine control systems.
The project began with the demolition of three fixed concrete piers. The piers, along with a new 250-foot dock, will be rebuilt as concrete floating docks to provide 84 expanded and enlarged superyacht slips. After the demolition of the piers, MLC hauled the 2 million pounds of concrete debris offshore where it was used to construct artificial reefs. The project then moved to the excavation phase:
“On land, you can put stakes in the ground, and you are good to go,” said David Logan, co-owner of Murray Logan Construction. “Out here, where we are dealing with a large site that changes with the tide going one way for six hours and then the other way for six hours, and water elevations that change by about two feet every day, twice a day, things aren't that easy. So, we needed a way to accurately cut the necessary slopes and various elevations — without seeing them.”
A Better Approach
Traditionally for MLC, underwater excavation would have entailed working off a bathymetric survey, followed by locating the barge/excavator to an area where a high spot was identified, then an effort to accurately locate it.
“When dealing with 14.5 acres of work area, that isn't very practical,” said Logan. “We needed a better approach.”
When researching possible solutions, Logan learned about the Topcon X-53i excavator system. With machine control, his operators could know — at all times — exactly where the bucket was, the depth and its horizontal and vertical location.
“It gives our operators a level of confidence they’d never had before,” he said. “There is no longer uncertainty about whether they've gone deep enough or whether they’ve done an area or not — it's right there on the screen in the cab.”
Seeing Efficiency in 3D
MLC also utilized Topcon’s Sitelink3D site management system for real-time project management, generating reports and more. “This solution gives us a real-time look at what the operators are doing,” said Logan. “It also allows us to manage the working surfaces with which they are working and do so from our office or elsewhere using any connected device. With Sitelink3D I can be seeing exactly what they are doing, and we can manipulate settings or manage the work area without the need for me to drive out there, get in a small boat and head out to the barge.”
History Loves Company
With an eye on the completion date and an unexpectedly high amount of rock being encountered, MLC turned to Vance Construction to augment the existing excavation process. Brad Albritton and Jim Vance of Vance Construction met with Logan to discuss the marina project.
“When we met, I showed them the machine control solution and the results we were gaining from it,” said Logan. “Almost immediately, they felt they needed to add it to their fleet as well. They’ve loved the results, and because they also do a lot of marine excavation, they see it playing a big role for their future work.”
“The Town Marina project has presented its challenges along the way,” Logan concludes. “But largely because of the performance of the machine control solution — and my team’s embrace of the technology — we will see a successful, on-time completion and Palm Beach will have a showplace of a marina.
Editor's Note: Scranton Gillette Communications and the SGC Infrastructure Group are not liable for the accuracy, efficacy and validity of the claims made in this piece. The views expressed in this content do not reflect the position of the Roads & Bridges' Editorial Team.