Manhole covers, you ask? Yes, manhole covers, those big, cast iron plates on streets that ensure you and I don’t fall into the depths of the Earth. Or at least into the sewers.
Unknown to most, there are lot of problems with traditional cast iron manhole covers:
- They’re heavy, weighing more than 50 kg.
- They’re popular to steal given the high price of iron; a serious safety risk due to the exposed hole that remains.
- Tying into the previous blog, they’re loud when driven/walked over.
- And, evidently, it’s a squirrel hazard…
As a result, researchers put on their thinking caps (for two years!) and came up with a solution: polyurethane manhole covers. Not only does the application of polyurethane provide extreme solidity and resistance, but it’s 70 per cent less heavy than cast iron (allowing for significant reduction in shipping and transport costs), results in 13-48 per cent lower CO2 emissions due to its innate resistance to corrosion, and reduces noise levels from passage of pedestrians and vehicles! Another benefit is that polyurethane isn’t sold as scrap, and thus polyurethane manhole covers act as a disincentive for theft and vandalism, providing us a safer community.
For our more visual readers, check out a short video on polyurethane manhole covers here.
For those that want something they can print out (though let’s be green and read from our screen), click here.
By the way, ever wonder why manhole covers are round? Check out the video below for one, amongst many, answers: