When it comes to constructing buildings in tight, urban spaces and highways in heavily trafficked areas, it can be difficult to avoid impacting ongoing activities of the general public surrounding the jobsite. With multiple truckloads transporting material as well as detours or lane closures affecting traffic flow, contractors face unique safety and logistics issues in urban construction zones. When preparing for these challenges, contractors must consider the safety of the public, on-site workers and the environment – while completing the job effectively and on schedule.
While some of these challenges are inevitable for buildings and infrastructure projects, Balfour Beatty leverages a unique method for transporting materials in high-traffic areas: conveyor systems.
Balfour Beatty’s innovative use of conveyor systems to transport materials in high-traffic areas reduces the carbon footprint of the project and allows for safer, faster project delivery with little impact to the surrounding environment.
Two Projects, One Simple Solution for North Carolina Department of Transportation
Balfour Beatty has successfully deployed conveyor systems on two projects for the North Carolina Department of Transportation (NCDOT) to move nearly four million yards of borrow material from the borrow sources and across two major North Carolina highways to the placement site. The use of conveyors on these projects eliminated thousands of truckloads of material from the highways and roadways, thereby safely separating work activities from the public.
The Military Cutoff Road Extension project in Wilmington, NC requires the movement of 1.8 million yards of borrow from the borrow pit and across I-140 to the placement location.
The Fayetteville Outer Loop project requires the movement of two million yards of borrow from the borrow pit located on the other side of I-95, which is the major highway located on the East Coast that stretches from the US/Canadian border to southern Florida. The project will provide interstate connectivity for the region, which is critical in supporting military deployment and national security, as well as promoting economic growth for the region.
Both projects presented an opportunity for Balfour Beatty to propose the innovative use of conveyor systems for moving borrow.
An Alternative Approach
Recognizing the client’s desire to safely separate construction activities from the general public, the Balfour Beatty team knew they had to find a creative approach to building these projects, not only to satisfy the client’s concerns, but also to be competitive during the bidding process. With these key drivers in mind, the team was determined to think “outside the box”. Thanks to the creativity and thought leadership of Operations Manager, Jay Boyd, the conveyor idea was born.
Without providing details about intentional use, Boyd reached out to friends in the industry who have used conveyor systems on highway projects to evaluate functionality and pricing. He spent hours understanding precisely how the system might work. Based upon Boyd’s extensive research and evaluation, Balfour Beatty decided to utilize his idea to bid the Military Cutoff Extension project. Boyd’s idea was fundamental to the team’s win for the $95 million project.
Subsequently, while brainstorming competitive solutions for the Fayetteville Outer Loop design-build project, Boyd conducted extensive research and once again concluded that a conveyor system would be an excellent solution for moving borrow from a strategically positioned borrow pit across I-95 to the material’s intended destination. In this circumstance, Boyd’s idea resulted in Balfour Beatty receiving the highest design-build technical score among the competitors and is directly attributed to Balfour Beatty’s win for the $129.7 million project.
When asked about Boyd’s winning idea, Southeast Region Vice President, Mark Johnnie, praised, “It’s one thing to come up with creative ideas, but it’s another thing to make those ideas come to life.”
“That takes determination, tenacity and a positive, can-do attitude – all of which Jay and the entire project team possess,” Johnnie added.
Why a Conveyor System?
A conveyor system is commonly known as a piece of machinery used to carry or transport materials from one point to another.
For both the Military Cutoff and the Fayetteville Outer Loop projects, the source of borrow material was located on the opposite side of a major roadway from where the material was needed. For both projects, the traditional means of transportation is for on-road trucks to load and transport the material to the other side. However, the volume of truckloads crossing public roadways would have caused traffic congestion and safety issues for the traveling public and jobsite workers. Not to mention, the cost for on-road trucking is more expensive than off-road trucking.
Conveying the material from the borrow source to the placement location solved safety and congestion issues and allowed Balfour Beatty to use traditional off-road haul trucks to handle the borrow. While conveying is not a new concept, what is innovative is the design of the conveyor, developed by the project team, that allows 40-ton, off-road trucks to haul and dump the material into a hopper that subsequently sends the material across the conveyor system to the opposite side of the roadway.
This feature allows the Fayetteville Outer Loop project to move borrow above the production rates necessary to complete the project on time, at a maximum 350-400 yards of material per hour.
“Jay’s idea is the essence of all the Build to Last tenets we live by at Balfour Beatty – Lean, Expert, Safe – and now that the systems are exceeding expectations, Trusted.”
“Our client, NCDOT, is thrilled with these solutions,” Johnnie concluded.
Leveraging Conveyor Systems Across Business Units
Balfour Beatty’s successful use of conveyor systems has also proven true during the development of a 42-story residential tower project known as 500 Folsom Apartments in San Francisco, California.
500 Folsom St. is a 42-story, 728,814-square-foot residential tower project with six levels of below-grade parking. The site conditions—both above and below ground—created logistical challenges for construction during the excavation and shoring processes.
With the project located in a busy, high-traffic area with logistical constraints, excavation would only allow for feasible truck access via a ramp up to 25 feet deep.
However, the depth of this dig compared to the length of the dig prohibited the use of a ramp, as it would have been too steep and too deep for an excavator to reach the bottom.
Balfour Beatty utilized conveyor machinery to extract soil from deep excavation that extended below 25 feet in the ground. Equipment was hoisted into the excavation with a mobile crane to “feed” the conveyor hopper, moving over 83,000 cubic yards of soil and saving 48 days of the construction schedule.
The use of a conveyor system on this project was a safer, more efficient method for extracting soil below 25 feet in the ground. Alternative approaches would have caused unsafe conditions for workers and loss of time on the project.
“Time is money in our business,” Senior Vice President of the California office Chet Brians stated. “Any time we can create safer conditions and deliver a project faster is a valuable benefit to our clients.”
Design Innovation for Safer, Faster Project Delivery
As we seek to provide a high standard of project solutions for our clients, innovation, safety and efficiency are leading priorities. The use of conveyor systems across our Buildings and Civils businesses aligns with our goals to be a Lean, Expert, Trusted and Safe partner in the communities we help build.