Final answer:
The student's question seems to pertain to engineering standards related to how guard rails are attached. The code (13-170) is not clear, but the question relates to the materials and methods used for securely fastening guard rails, in compliance with the relevant safety standards.
Step-by-step explanation:
The student's question, "Guard rails are fastened to running with (13-170)?", appears to be seeking information regarding the specifications or standards that pertain to how guard rails are attached to running boards or supports, likely within a structure or along a roadway. However, the code or specification '(13-170)' is unclear without additional context. In the realm of engineering, attaching guard rails to their supports requires careful consideration of the materials, fastening methods, and compliance with safety standards to ensure they can adequately protect against falls or vehicle egress.
For instance, in the construction of highway guard rails, standards such as those provided by the American Association of State Highway and Transportation Officials (AASHTO) may be referenced for proper installation and safety requirements. These standards would specify the types of fasteners, the spacing, and the required strength to withstand impacts.