Where is the 9-meter turning radius of a fire truck measured from?
3 Answers
The minimum turning radius of a fire lane refers to the radius of the circular path traced by the outer side of the front wheels when the vehicle is turning. Relevant information about fire lanes is as follows: 1. Width and height of fire lanes: According to the "Code for Fire Protection Design of Buildings," the clear width and height of a fire lane must not be less than 4 meters. 2. Turning radius of fire lanes: According to the same code, the turning radius of a standard fire truck is 9 meters, while that of an aerial ladder truck is 12 meters, and some special vehicles have a turning radius of 16-20 meters. Therefore, the design is generally based on the 12-meter turning radius of aerial ladder trucks.
We firefighters pay special attention to the turning radius issue when driving. That 9-meter measurement starts from the center point of the outermost front wheel of the fire truck, referring to the arc radius drawn by the front wheels during a turn. Every time we respond to emergencies in narrow alleys, I have to visually estimate if there's enough turning space in advance, because the rear wheels follow a slightly tighter path. Our training ground has specially designed simulated curves with a 9-meter radius - if you can make the turn in one go, you're basically qualified. Fire station exits are all designed with turning areas meeting this standard to ensure smooth emergency departures. When encountering old alleys where a 9-meter turn isn't possible, we have to rely on smaller support vehicles or adjust hose deployment plans on site.
As an urban road designer, I frequently use the 9-meter turning radius parameter for fire trucks. The measurement starts from the center of the outermost front wheel, and the radius of the arc drawn during the turn is this value. For newly built main road intersections, we reserve at least 10 meters for the inner turning radius. The most challenging aspect of old town renovations is meeting this dimension. When designing microcirculation road networks, it's particularly troublesome—tree pits and bus stops must avoid the turning area, otherwise fire trucks can't pass. During a recent residential area inspection, we found a flower bed obstructing the turning path, resulting in a complete redesign of the entire landscape strip.
