[littleblazer]

First compliment I’ve ever gotten on handwriting. Thanks. Learned through many classes to keep work at least somewhat organized, especially complex dynamics problems. So many sheets per question sometimes.

Even this simple problem took me a few minutes to remember approach and best axes to use.

Any time sir. My work was always organized... just difficult to read lol. I kept my reaction engineering notes as a reference... (figured that and design would be most useful) and turns out I can read them but they were useless to anyone I shared with. It is coming in clutch with my current job/projects but I enjoyed the physical and physics side more. Almost switched into a physics major.

 

[Abe17ZR2]

For short bed, you're loading just below 75% (73%) of 8' board weight directly down onto your tailgate with it up. At roughly 450 lbs, probably not the end of the world. I think you're fine either method, but your call obviously. If stack of lumber is above lowest tie-downs, flat is nice and easy to load and secure.

FYI, for those with long beds loading 8' lumber/sheet goods, the weight drops to 62% weight onto your tailgate with it up.

And yes, I proved 0=0 to verify rest of my calcs were correct. Boards/sheets are also distributed loads, not point loads, but ran it as a point load for simplicity. Anyone that feels like finding the answer using a correct distributed load, feel free to do so. LOL

View attachment 440795

Holy ****, is that what it takes to figure out these things? **** that lol but thank you for taking the time to do it. Very cool

 

[gherbert]

Man... I wish my hand writing was that neat through physics. Lot of fun with that class though... the subsequent years of torture not so much however. Very elegant.

When I used to do EMS
My Captian would write ... And you would swear it was typed

 

[spb1122]

Wow.
The OP's very first post, and this is what you guys throw at him?
That's a joke, nobody get ruffled. I respect the physics, math and other science applied here.

Having moved untold loads of lumber myself, my opinion is:

For the load you described, either way is fine, so I wouldn't really over think it. Some variables to consider are:

• Your load/unload preference or conditions.
• How far you're traveling, and the road conditions for your trip (rough, all smooth, stop/start).
• Type and condition of the 2x6's. Regular fir/pine/spruce framing lumber? Pressure treated? Wet/frozen?
  • Pressure treated and/or wet/frozen can increase weight significantly
  • Frozen boards of any type will slide around in the most amazing ways.
• Do you care if you mar the plastic tailgate cap?
• What type of tie-down straps you have available.
• You mention 8' boards, and what I'm writing applies to 8' lengths, or shorter only.

If I was loading on top of a closed tailgate, I'd ratchet strap across the tailgate end of the truck and call it a day. Between the wheel wells you should fit a 7 wide 4 high stack, with the remaining four boards centered on top. A good rope works for this method too, as long as you are capable of tying it off snug. The main goal is to stop the boards from sliding left to right in turns, or bouncing on bumps. Ratchet strap is better though. I do not recommend bungees. I know loads of guys who would load that many boards that way, and not even tie them down. And I've seen it done successfully more times than I can count. HOWEVER, I DO NOT recommend moving them that way. Tie them down please.

If I was loading with the tailgate down, in addition to the sliding left/right and bouncing up and down mentioned above, sliding out of the back of truck becomes something to take care of. I would make the same stack as above, but put two straps around the load itself, one in front, one in rear, binding it into a tight bundle. Then, strap the load down to the truck, including weaving the tie down straps to the binding straps in some way. Still don't go trying to light 'em up on take off, or put her on two wheels in a turn. I think ratchet straps are the best choice for this method.

For the 32 - 2x6x8' boards you described, I'd go on top of a closed tailgate if it was me.

 

[ForteDJ]

Holy *, is that what it takes to figure out these things? * that lol but thank you for taking the time to do it. Very cool

May be other ways, but this is the widely accepted approach, using a free body diagram for one of your members(no, not that member) and solve net force and torque sums taken at different points along member. Having done a bunch of these problems in school this one is relatively simple with all forces in vertical and no pinned/fixed connections.

Glad people find it useful. Maybe I’ll go full nerdgineer and make a spreadsheet for varying load lengths. 😂🤓

 

[_Montana_]

Jokes on all you, OP moved that load 2 hours after posting lol. jk jk.

 

[Abe17ZR2]

May be other ways, but this is the widely accepted approach, using a free body diagram for one of your members(no, not that member) and solve net force and torque sums taken at different points along member. Having done a bunch of these problems in school this one is relatively simple with all forces in vertical and no pinned/fixed connections.

Glad people find it useful. Maybe I’ll go full nerdgineer and make a spreadsheet for varying load lengths. 😂🤓

Honestly that would be super useful, I'm always thinking, "man I have no clue what I'm doing, but is it dangerous? Guess I'll find out." The most I do is ok yeah it's within the specs posted on the sticker in the door jam, in good lol

 

[KayakDiver]

More simply you can use the ol' a2 + b2 = c2 (Pythagorean Theorem) for the fulcrum distance, then find the ratio of C to the total board length and multiply that by the total weight (probably just a bit easier for us non-mathematicians!). The result would be very close but doesn't consider the slight offset caused by tilt or the thickness of the board pushing away from the front of the bed, although the latter mitigates the former by ~half the board thickness (I think). OK, let's just go with what ForteDj said! 😁

 

[_Montana_]

More simply you can use the ol' a2 + b2 = c2 (Pythagorean Theorem) for the fulcrum distance, then find the ratio of C to the total board length and multiply that by the total weight (probably just a bit easier for us non-mathematicians!). The result would be very close but doesn't consider the slight offset caused by tilt or the thickness of the board pushing away from the front of the bed, although the latter mitigates the former by ~half the board thickness (I think). OK, let's just go with what ForteDj said! 😁

 

[Verpus77]

Loadd sheet

 

[sukhoi_584th]

You can use the trailer hitch as hooks for a ratchet strap with the tailgate down. Haven't seen that mentioned.