Turning Radius Guidelines for TrucksThe truck shown is a standard truck used by CXT Incorporated. The information below will help you determine if your building will make it to your site (special arrangements MUST be made for Double Cascadian and Double Cascadian with Chase).Standard height of building on the truck is 13’6″.
If you have low power line, bridges, tree limbs, etc. Please call the Logistics Coordinator at 800-696-5766 for special arrangements. Standard widths change on each building. A good rule of thumb I’ve used for the last 10 years with mainly 53′ and 48′ trailers:Don’t try to turn around unless you have at least 4 1/2 to 5 lanes of road worth of distance (this has to be kind of eyeballed) or you won’t have enough room to get the tractor all the way turned OR if you three-point turn you will jack-knife and not have enough radius to get the trailer all the way turned. One results in getting the tractor stuck and the other involves getting the trailer wedged in to the side of the tractor.
Need ACAD turning templates 2. A WB67, which is on of the largest semi trucks on the road and has a trailer length of 53' +/- requires an inside radius of at least 22'. That is the tightest it can turn with the power steering screaming and the wheels smoking. If you design for a larger than 22' inside radius, you should be fine.
Tractor-trailers are complex beasts; every aspect of the unit's performance depends on dozens of factors within not only the truck but the trailer also. A truck's purpose is to tow a trailer, which is why the trailer makes up most of the unit's size and mass. So, you don't need to ask what the tractor's turning radius is, since the unit's overall turning radius and diameter usually depends more upon the trailer than the tractor.
Either way, all you need is to apply a bit of simple trigonometry to calculate the truck's steering and Ackerman angle. Break out your trig calculator, enter the degrees of steer angle and hit the 'sin' key.
In the example, we wind up with 0.819. Now, divide the wheelbase of the truck by your sin figure; for the example, the result is a turning radius of 305.25 inches, or about 25.43 feet. Multiply that by two to get the truck's total turning diameter, or turning circle, which is 50.87 feet for our example.
If you're measuring that in traffic lanes, that's five 10-foot-wide country roads or a little more than four 12-foot-wide state roads to do a U-turn. Perform this same calculation with the trailer, but this time measure from the center of the tandem trailer tires to the center of the drive axles and use the angle of the truck relative to the trailer as your steering angle.
With the 53-footer's tandems set all the way forward, the wheelbase measures 400 inches. With a 10-degree angle of truck to trailer the turning radius is 2,312 inches, or 192 feet.
Increase the turning angle to 45 degrees, and turn radius decreases to 565 inches or 47 feet. Jackknife the truck at 90 degrees or more and the trailer rotates on its tandems with a turn radius of 400 inches or less. Tips. Measuring from the center of the drives or tandems isn't a perfect approach, mathematically speaking, but it's the best way to get an estimate since you have no way of knowing which set of tires are slipping and which are grabbing to act as a fulcrum.
Taking the average this way will get you very close to the actual turn radius, which may vary depending upon load distribution, tire pressure, tire grip and road surface. If you don't have a trig calculator, just go to your favorite web browser and type 'sin of degrees' into the search window. Most browsers will offer up this kind of general information without directing you to a separate page.