Aggregates Manager Digital Magazine
Issue link: http://read.dmtmag.com/i/742224
14 AGGREGATES MANAGER / November 2016 PLANT PROFILE varying percentage of natural products. Some areas have more sand, and some areas are rockier. The drone lets us know what we need, and we can adjust our operations in the pit to get that. We are using it currently to check the progress of how the pit is going. Eventually, we will use it for mine planning, elevations, and topographical maps." The drone flies a pre-programmed route in the plant that is entered into an iPad. When the drone takes off, it goes straight up to an altitude of 350 feet and begins following the flight pattern over the stockpiles in the plant. The drone's flight can be followed on the iPad, which shows the flight pattern and the drone's location at all times. At the end of the flight, it returns to and lands in the same spot as takeoff. All the data and images from the flight are uploaded into the Cloud, where they can be accessed by plant or company personnel. Lehigh Hanson leases the drone and flies it at several plants in the Bay Area, including at least once a month at Mission Valley Rock. Currently, the drone makes two separate flights to measure all 45 stockpiles at the plant because of its limited battery life and the speed at which it travels. However, a new drone is expected to change all that. "We're pretty excited about Kespry's new drone," Moy says. "The new one will measure all the stockpiles in one flight and save us a lot of time. It's a lot faster and covers twice as much ground. Anoth- er neat thing about this is it will actually do 3D models of what was flown, which is really nice for the pit so we can see all the steps. Day-to-day operations Like most aggregate operations, the day starts early at Mission Valley Rock. "It's always busy in the morning. The truck drivers are trying to beat the traffic, so we start loading trucks at about 5:30 – 5:45 a.m.," Johnstone notes. "Our weigh- master gets here at 5 a.m. so he can get things up and running. We start running from the pit at 6 a.m." "Our entire pit, for a million tons of product a year, is operated by one D10 dozer and one 375 excavator," Zacharis- en notes. The dozer pushes the mate- rial down the slope, and the excavator scoops it up and dumps it into a hopper that feeds it onto a series of overland conveyors that carry it under the high- way and up to the processing plant. From there it is screened, washed, and sorted into one of the final product stockpiles at the plant. An asphalt plant and a ready-mix plant are also located on site. Lehigh Hanson owns both plants, but only op- erates the asphalt plant. The ready-mix plant is leased out to Central Concrete. In addition, the aggregate plant is in the process of developing a market for the larger cobbles coming out of the pit that would normally be crushed. "It's coming along," Zacharisen says regarding the cobbles. "We installed a diverter chute to collect them and then scoop them out with a loader and stack them. It's landscaping material. You see a lot of it on clover leafs on freeways in Ar- izona, but not as much in California. We hope we'll find a good market for them." All of this work is done by 22 hourly employees and three salaried employees. Zacharisen is proud of all of his workers, but has an especially soft spot for the maintenance crew, which addressed his fear of heights by extending the height of the railing on the screen tower to make him more comfortable about going up to observe operations. "Our maintenance crew is amazing," Zacharisen says. "Some of the things they fabricate save us a ton of money. They'll fabricate screen frames or rebuild an entire screw. I think that type of skill is vanishing. When I first got here a year and a half ago, I was just amazed at what they could do. They're a rare breed, and we're very fortunate to have them." Safety is #1 Safety is a daily priority at Mission Valley Rock. Not only do they have the typical daily safety meetings, but each employee is also responsible for inspecting a zone or portion of the plant every day. The concept is that having the same set of eyes on each section of the plant will make it easier for them to notice anything that's out of the ordi- nary. Every employee fills out a working Mike Moy, operations analyst for Lehigh Hanson, prepares to fly a drone to measure all 47 stockpiles at Mission Valley Rock.