In non-geocaching society, a guardrail is a system designed to keep vehicles from straying into dangerous or off-limits areas. Guardrails redirect a vehicle away from embankment slopes or fixed objects and dissipate the energy of the errant vehicle. They prevent vehicles from veering off the roadway into oncoming traffic, crashing against solid objects or falling into a ravine. They also keep the vehicle upright while deflected along the guardrail during an accident.
Guardrails are generally required by code where there is a drop of 30" or more.
The design of a guardrail can vary, depending on how it is intended to be used. As a general rule, the guardrail takes the form of a long strip of strong cast metal attached to posts. The metal is stamped so that it has multiple ridges. When something hits the guardrail, the ridges crumple, spreading the energy along the length of the guardrail. The multiple posts prevent a collapse, unless the impact is extremely heavy or at very high speed.Although a guardrail is intended to protect the public, a number of safety concerns are associated with guardrails, particularly those designed to work with automobiles. The first is the “end treatment,” or the finish on the end of the guardrail. Formerly, guardrails were not capped or finished in any way, leaving a wedge of sharp steel at either end of the stretch of guardrail. If someone collided with the end at a high rate of speed, the guardrail could potentially penetrate the car, causing injuries or death. Most modern end treatments are curved or flattened, and designed to resist the impact slightly.If the guardrail or end treatment is too strong, it also has the potential of thrusting the car back into traffic. Therefore, most guardrails are designed to absorb energy, rather than deflecting it. In addition, traffic engineers have to think about the height of a guardrail. A tall vehicle may flip over a low guardrail, but a motorcycle could slide under a high one. Therefore, the height must be carefully considered before a guardrail is installed.
There are four general types of guardrail, ranging from weakest and inexpensive to strongest and expensive; cable and wood posts, steel and wood/metal posts, steel box-beam, and concrete barriers.
The blunt end of W-Beam guardrails feature protective rail end treatments designed to absorb impact or deflect oncoming traffic. High quality guardrail end treatments are constructed using high-strength 10 gauge (Class B) steel, and are coated in rust-resistant zinc for maximum service life.
Question Mark and Flared End rail end treatments are commonly used throughout parking lots and low speed traffic areas. Flared guardrail end treatments, also known as flared wings, provide rigid, straight protection for energy deflection during impact. Question Mark Guardrail End Treatments, commonly referred to as rounded terminal connectors or half-round buffers, are ideal for areas with high pedestrian traffic. Question mark terminal end treatments feature a curved surface to help prevent injury and torn clothing.
So, having learned your lesson about a guardrail, what ever does this have to do with a puzzle and geocaching? And where is the puzzle and where do I look?
Seriously, if you are anything but a day old newbie, this cache is so obvious. I mean really... What does a ? marked shaped guardrail and a ? mark shaped mystery/puzzle cache have in common, other than shape?
FTF goes to iampaw!