Some cannons were buried muzzle down, and others muzzle up. When up, the bore was usually sealed using an oversized cannonball.
In order to install pavers and impact-protective bollards, the level of concrete is set by the height of the paver. The loss of the thin level of paver material to the volume of the concrete surround will only minimally affect the stopping power of the bollard.
Rated security bollards have been rigorously tested to prove their stopping power. ASTM ratings are assigned to bollards based on the barrier’s ability to stop vehicles of different weights and speeds.
In our Future Cities series, we will look at how engineers and city planners are approaching the challenges and opportunities of our changing world. This week we celebrate innovations in water management in places like Northern BC; Milwaukee, WI; Gresham, OR; and Orange County, CA.
Speed is the primary factor in most vehicle accidents—increasing both risk and severity. As drivers move faster, they have less time to respond to road conditions and any resulting collision causes more damage. To counter the problem of speeding, municipalities can choose from a number of
Foundries are responsible for our current standard of living and industrial development, but most of us know next to nothing about them. So what is a foundry? Foundry Definition In simplified terms, a foundry is a factory where castings are produced by melting metal, pouring
Ductile iron – also referred to as spheroidal or nodular iron – is actually a group of irons that exhibit high strength, flexibility, durability and elasticity due to their unique microstructure. Cast ductile iron normally contains over 3 percent carbon; it can be bent, twisted or deformed without fracturing.