Final answer:
A trackman should report dangerous conditions such as the suction effect caused by rapidly moving trains, presence of dangerous gases, and structural integrity concerns. It's crucial for ensuring safety in the subway system.
Step-by-step explanation:
A dangerous condition that a trackman should observe and report in a subway system could be related to atmospheric pressure changes caused by rapidly moving trains, presence of dangerous gases, structural integrity issues such as ground prone to collapse, or inadequate deceleration of trains as they enter stations. It's particularly dangerous to stand close to railroad tracks when a commuter train passes because the train displaces the air as it moves, which creates a low-pressure zone. This can cause a suction effect that may pull objects or people towards the train. Reporting such conditions is vital for the safety and smooth operation of the subway system.
In addition, a trackman should be vigilant of any signs of underground mine fires or structural issues within the subway environment, which can pose severe health and safety risks. Regular checks for hazards, proper signaling of dangers, and immediate reporting can prevent accidents and ensure passenger and employee safety.