Aggregates Manager Digital Magazine
Issue link: http://read.dmtmag.com/i/594078
15 AGGREGATES MANAGER November 2015 part in reducing energy usage, and put photocells on the lights at the plant so they would turn on at dusk and off at sunrise. The operation only operates its 500-horsepower waste water pumps during off-peak hours, usually between 9 p.m. and 6 a.m. On high-temperature days, the operation runs only what it has to run, saving energy and money by not having to pay higher rates during peak, high-usage hours. "I've learned a lot over the years about how to turn things on and off in the plant in succession," Pro- noitis adds. "If everything in the plant is turned on at the same time, there's an in-rush of energy de- mand. Each operation is different, so you learn as you go. I got useful infor- mation from our ConEd representative, and for a while, we monitored our kilowatt hours." Shipping the material Another thing that helps Romeoville Quarry keep its energy costs low is the way it ships material. Approximately half of its products are loaded into customer trucks for de- livery, but the other half is shipped via barges on the Chicago Sanitary and Ship Canal, which is ap- proximately 24 feet deep and 200 feet wide. The canal, which was com- pleted in January 1900, was originally intended to divert waste water from the Chicago River into the Des Plaines River to keep it from draining into Lake Michigan, but it became an important shipping route for the area as well. The canal runs along the east side of the quarry's property, providing a conve- nient way to transport material by barge to cities along the waterway. The canal offers a straight shot into Chicago, which is approximately 35 miles northeast of the quarry. Most barges are in and out of the quarry in the evenings or on week- ends, as the goal is to be at the drop off area in Chicago early in the morning for delivery. Tow boats only move the barg- es between 5 and 7 miles per hour on the canal, depending on other boat traf- fic, so it takes approximately six hours to make the trip one way. "Barging is the most efficient mode of transporting aggregate," says Dar- ren Melvin, manager of Marine Opera- tions, a separate department of Lehigh Hanson. "We can move 1 ton of product 542 miles with one gallon of fuel on the waterways." There are also other advantages to de- livering material by barge, like reduced emissions. According to Melvin, one boat pushing six barges has only three diesel engines, so it can move 420 truckloads of material with the emissions from only three diesel engines. Plus, statistics show that there are very few incidents on waterways, as opposed to semi-truck and railcar accidents. "Barges are loaded and shipped about four times a week," Melvin says, explain- ing that there are several methods used to load and unload barges — a mate- rial handler and crawler crane, both of which are equipped with 5-cubic-yard clam shell buckets, and a sliding shuttle conveyor. "Each barge can handle ap- proximately 70 truckloads (1,500 tons) of material. We ship about 18 barges a week to the city, which amounts to 1,300 trucks, give or take, that we're keeping off the road. The numbers vary throughout the year, but it's probably in the vicinity of 100,000 trucks a year that we're keeping off the Chicago roadways, which is a good thing." Each tow boat has seven crew mem- bers. Since overnight trips are required to transport material on the canal, crew members work a 21/21 schedule. They live, sleep, and eat on the tow boat dur- PLANT PROFILE A sliding shuttle conveyor at Lehigh Hanson's Romeoville Quarry loads material onto a barge as a tow boat pushes six loaded barges toward the city on the Chicago Sanitary and Ship Canal.