Today composite materials are used in wind energy, marine, construction, aerospace, military and defense, automotive, pipes, access covers, tanks and many more applications. Composites offer several advantages over traditional materials: higher tensile strength, lighter weight, greater corrosion resistance, no re-sale value (so won’t be stolen), better surface finish and easier processing.
US-based manufacturer Fibrelite has seen a tremendous increase in inquiries for their lightweight composite access covers from industries keen to move away from the traditionally used metal and concrete and change specifications to composites (a future material).
According to a study by the National Association of Corrosion Engineers (NACE), the direct cost of infrastructure corrosion was over $22 billion in 2002 in the United States alone. Adjusted for inflation, the direct cost of corrosion in 2013 was estimated to be over $42 billion on an annual basis.  It has been estimated that at least 25 to 30 percent of annual corrosion costs could be saved if optimal corrosion management practices were employed.
Fiber reinforced plastic (FRP) products are now being widely used for applications where corrosion can destroy underground infrastructure. Perhaps the prime reason for using FRP products is because of their inherent corrosion resistance.
The corrosion resistance of FRP is a function of both the molding technology and the specific resin used in the laminate.  Today, various resin systems are available which can provide long-term resistance to almost every chemical and temperature environment.
One application in which FRP is being widely adopted worldwide and changing specifications away from metal is with manhole access and service trench covers. By helping to reduce the costs of corrosion, composite covers can allow utilities and other operators of underground infrastructure to improve the financial strength of their enterprises.
Founded on a tradition of quality and innovation, Fibrelite has been at the forefront of composite technology since 1980. The first ever composite manhole cover was designed by Fibrelite for gas stations, to eliminate health and safety issues associated with traditional metal covers. Today, Fibrelite is established as a leading world player in its specialist field, with a global reputation for high quality products.
With recent statistics attributing over half of injuries (resulting in absence from work) to manual handling it’s already known that reducing hazards in this area is a priority on a global scale. Because of legislation restricting acceptable manual handling weights, we are seeing a global trend towards lighter weight FRP composite manhole and access covers, which also have the benefits of ease of handling.
Lightweight composite covers that provide safe and easy access eliminating unsafe manual handling issues are replacing aging concrete and heavy cast iron access covers all over the world. By using lighter materials, operational injuries are prevented, work sites are made safer and ease of installation and maintenance is made available to utility workers and contractors.
The design of these lightweight covers incorporates up to two lifting points for specially designed lifting handles. These allow the operator to remove the cover without trapping fingers or bending over thus maximizing the safety of the lifting technique. The weight is kept close to the body preventing back injury; one of the main causes of absence from work and personal injury claims.
In response to customer demand, Fibrelite now offers company logos and other brand markings on its covers. Any style logo or other marking can be permanently molded into the upper surface of the cover in single or multiple colors. For additional brand or product identification, or to blend in with the color or layout of a facility, Fibrelite can mold its composite covers in nearly any color or combination of colors.
By introducing the pigment directly into the resin system during the molding process, Fibrelite ensures that the color is not merely applied on the surface of the cover. Instead, the coloring is evenly and completely infused throughout the composite cover and will not fade or wear over time.
Customers have utilized Fibrelite’s molded marking and coloring process to identify underground systems in a unique and highly visible way. Color can also be used as a quick and reliable method of identifying underground systems, thereby providing maintenance or emergency personnel with more accurate information about any hazards or special conditions related to the underground infrastructure.
The metal theft epidemic is not going away. There are few industries that can hide from the thieves and the water industry is still being severely affected. Cast iron and steel manhole covers and drainage grates are routinely stolen for the scrap value of the metal cover or grate.
And while the financial cost of replacement is quite high, the thefts also lead to open manholes which create significant hazards. Composite covers can solve this problem as the fiberglass material used has no inherent scrap value.  With the inability to melt down composite covers into quick cash at the junk yard; there is no incentive for thieves to steal the covers in the first place.
FRP composite manhole covers are ideal for problem areas, particularly those prone to skid related accidents. Traditional cast iron covers quickly become polished and therefore provide a poor level of grip which can lead to serious accidents through increased risk of skidding and slipping, even more so when wet.
“Fibrelite’s covers incorporate a molded anti-slip tread pattern equivalent to a modern high grade road surface. In fact, Fibrelite’s anti-slip/skid surface is guaranteed for the life of the cover providing a Polished Skid Resistance Value PSRV60> when wet which exceeds the requirements of HA 104/09, part 5, for potentially high risk sites,” says David Holmes, technical director and head of product innovation.
Fibrelite’s access covers are lightweight, durable and very strong. They are manufactured using high-technology Resin Transfer Molding (RTM) production methods to create a highly engineered, monolithic composite product. This offers the best strength to weight ratio in the industry, allowing for maximum load bearing strength and durability while remaining lightweight and easy to handle.  Fibrelite’s standard manhole covers also offer watertight solutions in a wide range of sizes and shapes.
Fibrelite’s comprehensive range of FRP composite trench covers are perfect for covering large areas, gullies, trenches and ducts where occasional or frequent access may be required. In fact, custom sizes are also available. ■
About the Author

Jo Stott is the marketing director for Fibrelite. Technical experts from Fibrelite will be on hand at this year’s WEFTEC to demonstrate new product innovations at Stand 7913, Hall 11. For more information, visit

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