What is tail swing and why is it a problem?

Discussion in 'Experienced Truckers' Advice' started by MACK E-6, Apr 29, 2024.

  1. Ex-Trucker Alex

    Ex-Trucker Alex Road Train Member

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    Well, that's only because he was too heavy to have them that far forward, as prescribed by the federal bridge weight formula (Bridge Formula Weights- FHWA Freight Management and Operations). This is true in every state in the US, although it's rarely calculated (since it seems DOT officers are just as bad as truckers in doing math..). For any weight of a load beyond one that's 'trivial', there is a minimum distance back from the drives that they must be. At the same time, many states limit how far back from the kingpin the last axle can be.

    So, the mistake that rookie drivers often make is that they THINK it will be easier to turn into a slot with the tandems all the way forward. But, with something like 14' of tail swing, you really need to be almost perfectly aligned with that slot before you back into it. For spaces like these (truckstops, crowded docks, inside docks, etc.), it's actually easier to reverse in with the tandems back at the bumper.

    I often used to leave my tandems unlocked when maneuvering in odd/tight quarters, sometimes stopping to slide them partway through.....
     
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  3. MACK E-6

    MACK E-6 Moderator Staff Member

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    Somewhere a long time ago I read about there being a law stating that rear overhang cannot exceed 35% of total wheel base. I’m not sure but it might be what @25(2)+2 is talking about.
     
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  4. MACK E-6

    MACK E-6 Moderator Staff Member

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    Everything I’ve EVER hit was because of this, which is why I’m exceedingly nervous about it now.
     
  5. Cat sdp

    Cat sdp . .

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    Real trailers have axles at the back that don’t move……..

    lol
     
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  6. ‘Olhand

    ‘Olhand Cantankerous Crusty

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    Trouble is the different states and their bridge laws of course cali&coneticut are the most ridiculous although Cali is the only one I used to see enforce it so stringently

    Yup but ya better #### sure be standing there tellin em how to load it….cuz tellin em 3 singles in the nose jus baffled em
     
  7. 54international

    54international Bobtail Member

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    If you try a sharp turn like that with a flatbed you might get a surprise.

    The trailer weight will cause the 5th wheel to tilt and the trailer will follow tilt.

    Can't back out of it either.
     
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  8. 25(2)+2

    25(2)+2 Trucker Forum STAFF Staff Member

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    The rule was spelled out in one of my truck atlases. Been a long time since I looked at it. We had a few trailers with longer slides set up for going to FL, those were the only reefers we had that we had to worry about that rule.

    Dry vans would slide farther than most reefers as a rule.
     
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  9. 25(2)+2

    25(2)+2 Trucker Forum STAFF Staff Member

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    A quick search stated not greater than 35% of the wheelbase of the trailer.
     
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  10. abyliks

    abyliks Road Train Member

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    nah, tell ‘em turn all their #### sideways and stack it to the chute

    this is why I don’t understand guys #####ing about turn radius, if you turn a trailer so tight that the trailer tires start turning backward it should be automatic termination
     
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  11. Hammer166

    Hammer166 Crusty Information Officer

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    This is one of those things that propagated rapidly thru trucking because so many inexperienced trainers didn't know it was wrong. It was a last resort maneuver the first 20 years I've been trucking, the last 20 it's become SOP. You can't hardly find a fleet truck that the extenders haven't been crunched on. And it must be hell trying to keep those trailers aligned with all that torqueing and almost always in the same direction.

    Every time I see it done, I want to grab my bar and do some reeducating! :mad:
     
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