Why is it better to have the tandems slid forward when alleydocking?

Discussion in 'Experienced Truckers' Advice' started by expedite_it, Sep 16, 2022.

  1. expedite_it

    expedite_it Road Train Member

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    Yeah. I've known all that for many months now.

    And yesterday, Lester taught me why I need more forward space when performing a 45 degree alleydock back when the tandems are all the way to the rear than if the tandems are slid forward. I wondered about that off and on for many months.

    The only thing about this that I still don't understand is why people here think it is somehow less likely that the rear of the trailer will hit something on a 45 degree alleydock back if the tandems are all the way to the rear than if the tandems are all the way forward. Everyone keeps saying "because you don't have any rear overhang". Well, the trailer is 53' no matter what the wheelbase is. So that don't make me understand this.
     
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  3. expedite_it

    expedite_it Road Train Member

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    , it's YOUR RESPONSIBILITY!! ;):)

    The quote by me that prompted you to ask me why I keep asking a repetitive question does not answer the question I have now.

    I started this thread asking how it is easier to line up the tractor-trailer with a parking spot when one is making a 45 degree alleydock back with the tandems forward than if the tandems are to the rear. That question has been answered.

    My new question is the following: how does having more rear overhang (due to the tandems being forward) make it more likely that one will hit another trailer or other obstacle next to the parking spot than if the tandems are to the rear?

    Everyone keeps responding "because you have more rear overhang." That doesn't answer the question!
     
  4. LtlAnonymous

    LtlAnonymous Road Train Member

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    Overhang. Mental lapse.
     
  5. expedite_it

    expedite_it Road Train Member

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    So how does this give the trailer more predictability when the truck is in reverse?
     
  6. drivingmissdaisy

    drivingmissdaisy Road Train Member

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    Less sensitivity. Longer wheel base means less movement of the back of the trailer when you turn the wheels. Shorter wheelbase means you get more trailer back end movement with every turn of your wheel. Can be handy in a very tight situation. But with trucks on both sides of you, that short wheelbase could result in trailer back end swing that could take the hood off of that '23 Peterbilt you admired when you were setting up for this back.

    You'll always back in "smoother" with tandems to the rear because of the lack of sensitivity to the trucks movement in the rear of the trailer. You'll need exaggerated truck nose movements to get the desired movements from the trailer if the back is a 90 degree and you might not have the room in front to do that.

    I actually backed into a dock one time at a place in Baton Rouge. The ONLY way my trailer would fit is tandems slid all the way to the front and the rig was at a 90 degree angle. Had I tried with the tandems to the rear I would have taken out a wooden picket fence that was 3 feet to the right of my rig when parked at a 90 to the dock.
     
    Last edited: Sep 18, 2022
  7. expedite_it

    expedite_it Road Train Member

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    I think you have answered the question here. I think that maybe the reason that other people did not answer the question is they didn't know how to describe this.

    I have been wondering about this stuff all year.
     
  8. LtlAnonymous

    LtlAnonymous Road Train Member

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    Or you just don't know much about jargon despite being an experienced driver. You should've gotten what we were getting at, but somehow ya didn't. *shrug*
     
  9. expedite_it

    expedite_it Road Train Member

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    I did get it when drivingmissdaisy spelled it out for me.

    When you were a student, did your trainer explain all this stuff to you? Mine didn't.
     
  10. expedite_it

    expedite_it Road Train Member

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    On further reflection, I am kind of glad you said this. On privates messages and other threads here, some people act like I am 5 year old or a toddler for having to ask these questions. The subtext of what other people have said to me when discussing this stuff on other threads seems to go something like this: "Any five year old could tell what ALL the advantages and disadvantages of having the tandems slid forward or all the way back while doing a 45 degree alleydock back are just by watching the tractor-trailer. How dare you ask us these questions!"

    I have always thought that these issues are not the most obvious things in the world.

    People have mocked me on other threads by asking me questions like the following: "If a man lengthens his suspenders, does it cause his pants to ride higher or lower?"
     
    Last edited: Sep 18, 2022
  11. N00bLaLoosh

    N00bLaLoosh Road Train Member

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    It shouldn't. If you're approaching the hole and you're at a severe enough angle that overhang matters then pull up and re-adjust, just like you'd do if your tandems weren't forward.
     
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