Weighing solution clears reservoir fire sediment

Edited by the Processingtalk editorial team Dec 24, 2007

The San Gabriel reservoir in Los Angeles had more than 6M cubic yards of forest fire sediment cleared from it in just three years, thanks to an Avery Weigh-Tronix weighing and data management system

A series of forest fires in the Angeles National Forest had caused the sediment build up.

The San Gabriel Reservoir is essential to Los Angeles citizens, as the reservoir creates electricity, delivers fresh water, and provides protection from storms, so the L.A Department of Public Works employed Barnard Construction Company to return the reservoir to its prior capacity.

Each of the Barnard trucks would need to carry sediment loads from the reservoir to an engineered fill located 2.5 miles away.

After evaluating the degree of sediment deposited in the reservoir and the efforts needed to remove it, the company worked out that it would them take five years to complete the project.

"This wasn't a project we could work on continuously, due to the rainy winter season, and these projects are normally very time-intensive," said Gavin Tasker, project manager at Barnard Construction Company: "We originally had a five-year plan in place, but we were able to work more efficiently than expected, largely due to the Avery Weigh-Tronix system".

For this project Barnard needed to process weight information from 200 to 300 trucks a day, each of which carried loads of up to 25 tons of sediment at one time.

The Avery Weigh-Tronix solution streamlined the Barnard efforts to the point that an average of 800 to 900 trucks were weighed each day, and on some days more than 1000 trucks were processed in a nearly non-stop weighing operation.

"We were able to complete the project in three years," Tasker added: "The L.A Department of Public Works had an immediate need to have the reservoir cleared, and they were delighted when the project was completed two years ahead of time".

The Avery Weigh-Tronix system, consisted of a BridgeMont weighbridge, an E1310 indicator, and custom software designed to read and interpret data from RFID tags placed on Barnard trucks.

The E1310 indicator acts as the brain of the weighbridge system and processes the weight calculations and truck information in an Excel spreadsheet format.

All this data was collected and processed within three seconds of the truck entering the scale.

"Often the truck didn't even need to stop completely," Tasker said: "Once we installed lights at the scale, so that trucks knew when to stop and go, the scale operator didn't need to run the lights or even talk to the truckers.

The scale system was self-contained; it was able to operate on its own".

Along with the two years cut from the project's original estimated timeline, Barnard also made significant cost savings.

"When we estimated how much this project would cost, diesel fuel cost about a dollar," Tasker said: "Fuel costs doubled as soon as we started working on the project and carried on rising.

The same thing happened with steel piping costs, along with price escalations in construction materials.

Basically, every year we waited to finish this project, it would cost us more than we expected.

The time we saved gave us major cost and overhead savings.

Plus, we were awarded the Marvin M Black Excellence in Partnering Award from the Associated General Contractors of America for this project".

Due to a combination of determined workers and a rugged weighbridge system, the San Gabriel Reservoir has now returned to fully functioning order just three years after its restoration project began.

The weighbridge weighed 800 trucks a day and 6.1 million tons of sediment and is still in perfect working order.

Said Al Beacher from Avery Weigh-Tronix: "This scale wasn't designed to handle weighing this many trucks in a day, but the only maintenance the scale needed throughout the entire three-year project was the replacement of two outer cover plates.

Originally Barnard wanted to sell the weighbridge back to us after the job was completed, but they were so impressed that they decided to keep it for future projects".