Dozens of cities across the U.S. are dealing with illegal scrappers. These are criminals who break into empty homes and commercial buildings. They strip every bit of material that can be sold to a scrap yard. While copper and brass are particularly valuable, scrap iron is also worth stealing if it can be taken quickly.
Manhole covers are particularly vulnerable. All an illegal scrapper needs is no one looking for a minute, a hooked metal rod to lift the cover past the lip of the hole and another person to help lift and toss the cover into the back of a car or truck. Even the smallest manhole cover weighs about 114 pounds.
Depending on the location, scrappers can get up to twenty cents a pound. That’s $22.80, so grabbing 5 covers in the middle of the night means a fast $114 for less than thirty minutes of actual work. Cast iron especially isn’t cheap when you buy is in a finished product. Replacing stolen covers can cost a city government as much as $300 for each one taken. These are the first and second benefits to replacing cast iron manhole covers with composites; cost and scrap value.
Composite covers are cheaper to produce. The $300 cast iron cover is only $199 – $219 for a comparable size. Even better, a manhole cover made of composite materials has a value of $0 to a scrap yard. There is no financial benefit for a thief to waste a moment on a composite manhole cover. This makes them extremely valuable to a city Works Department on a tight budget. That’s nearly every department in the country today.
Besides the obvious cost benefit, there is the weight issue. As mentioned above, a smaller cover weighs 114 pounds. That is a 22 3/4″ in diameter manhole cover. One made from composite materials weighs only 42.5 pounds. That’s a reduction in weight of over 65 percent!
This means that, in many cases, a single person can lift, remove and replace a manhole cover to accomplish an inspection or complete a work order. Manpower that is currently wasted to handle cast iron covers can instead be used to handle another work order, increasing the efficiency of that city’s Works Department.
A reduction in the weight that a Works Department employee has to move also reduces the stress on their backs. A 42.5 pound cover that lands on a foot is a lot less likely to smash a few toes than one that weighs 114 pounds. This means there will be fewer strained backs and other accidents as employees rush to get through their list of work orders by the end of the day. That translates into fewer hours lost to injury and smaller, annual healthcare costs. This makes replacing even a few dozen manhole covers look like peanuts in comparison.
In addition to all this, there is the wastewater issue. Cast iron covers have to be designed to fit loosely in order to easily remove them. They also still have a ‘keyhole’ to allow a city employee to use a hooked tool to lift them. This lets an incredible amount of runoff into the sewer system which has to be dealt with at a sewer plant.
Composite manhole covers can be built to seal completely. Since a composite cover can be molded, it can be designed to lock into place using a worm gear system. These require no ‘keyhole’ and block rainwater or other runoff from getting into the sewer system.
Even considering only the material and labor costs, phasing out cast iron manhole covers with composites is a good budget decision. Adding in the reduced healthcare and sewer treatment costs should push replacing cast iron with composite manhole covers much farther up a city’s priority list.