truck-trailer-crane turning radius

[bessie]

New here, plz help. how do i calculate the turning radius of a trailer truck, such that i want to install a crane in between the cabin and kingpin.

 

[Artisi]

Do you mean the clearance (distance) between the cab and the trailer when turning?

 

[SincoTC]

Check out this thread from last November:

http://www.eng-tips.com/viewthread.cfm?qid=201857

Trevor Clarke. (R & D) Scientific Instruments.Somerset. UK

SW2007x64 SP3.0 Pentium P4 3.6Ghz, 4Gb Ram ATI FireGL V7100 Driver: 8.323.0.0
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[bessie]

Yes Artisi, this is what i meant. I have checked the nov thread sincoTC recommends; is there a mathematical way instead of AutoTurn? the crane in the middle of the cab and trailer is confusing my maths.

 

[JStephen]

As i recall from long ago, the turning radius varies depending on particular model of truck as well as wheelbase, etc.

 

[rmw]

I don't think the OP is really asking the right question. The turning radius of a T/T rig is a function of the tractor wheel base and the maximum steer angle, etc. That said, due to the nature of the question, I think the question relates to the swing radius of the trailer nose (corners) into the zone that might soon be occupied by the soon to be mounted crane.

If that is the question, then it is a simple math problem related to the king pin spacing and the trailer width with any special considerations for anything extending beyond the normal trailer dimensions (reefer for example).

I do suggest the OP clarify the question.

rmw

 

[swearingen]

If I'm understanding the question correctly, the simple answer is to measure the distance from the center of the kingpin to a front corner of the trailer. Then, if you draw an arc of that distance from the center of the 5th wheel on the truck, your crane must stay outside that arc.

Granted, there needs to be a little play in that for when the truck goes up a ramp/hill and the 5th wheel has to rock forward. You can measure this distance as well, however. Measure the distance from the center of the rocker pin on the 5th wheel to the top surface of the trailer when hooked up. Multiply that distance with the sine of the angle between the 5th wheel level position and 5th wheel full tilted forward position. If you add that distance to the arc above, there should never be a strike.



If you "heard" it on the internet, it's guilty until proven innocent. - DCS

 

[bessie]

Apologies for the lack of info. I was thinking of a simple pythagora's calculation: when truck is turning 90deg, width of trailer (vert), dist from kingpin on trailer (horz) and find the 3rd side (hyp) - and this distance gives the max - which i thought would be same as the turning radius (drawing the arc from kingpin, joining two ends(2 corners of trailer)).

 

[MechEngInBC]

What Swearingen explained would be the best way to solve this problem.

The worst case for clearance is not at the 90 deg (truck to trailer), it would be at around 45 deg depending on the geometry of the trailer. Basically the angle where the line from kinpin to front corner of trailer travels to the point where it is directly in line with the center of the truck.



RobHend