One of the biggest nightmares for truck drivers is causing their vehicle to jackknife. This is a position which can put the driver in serious peril if they are still travelling at considerable speed. To prevent a jackknife at all possible is the goal of drivers who find themselves facing this particular situation.
By definition, a jackknife happens when the angle between the tractor a trailer reach a point where the driver is unable to straighten it out. Angles of up to 15 degrees can be rectified by the driver if they act quickly enough. Once past that point, preventing a jackknife may not be possible.
What Causes a Jackknife?
There are two basic ways that a jackknife can occur, either when the trailer of the rig starts swinging outwards or when the tractor starts skidding in a sideways manner. A tractor skid may happen when the drive wheels are spinning from too much power being applied or from over-breaking and the engine cutting back. Other reasons include turning at too fast a rate of speed or if the tires cannot keep the tractor on its proper course.
While a jackknife can occur on any road condition, they most often happen when the roads are slick with rain, slush, snow or ice. The trailer for example can swing out from over-braking with other road conditions contributing to the effect, including rough roads, sharp turns or if the crown of the road is quite high.
How to Prevent a Jackknife
The best way to keep a jackknife from happening is by not creating the conditions in the first place. If you follow these tips, then preventing a jackknife is much easier.
- Brake before you begin the turn
- Decelerate slowly and try not to hit the brakes hard
- Apply the proper power to the drive axle in a smooth fashion
- Keep the gear shifting smooth and engage the clutch in the proper fashion as well.
The trolley valves are there for a reason, but you can lock up the trailer wheels if you are not careful. Plus, if you are travelling on a slick road and start to brake, keep an eye on your mirrors to see if the trailer starts to swing out. If it does, release the brakes until the trailer is straight again, then try the brakes again.
If the jackknife starts under conditions other than braking, then you will need to steer your way out of the situation. The sooner you can start the correction, the easier it will be. Therefore in preventing a jackknife the key is being alert so that you can bring everything into line faster and with fewer issues.
It is possible to drive for many years without ever experiencing a jackknife because they take a little time to plan and prepare so that they are ready when it the situation arises. While a jackknife will happen to the best drivers, the frequency of the situations when it might occur can be significantly reduced if you take the time to learn how to prevent a jackknife.