Design challenge: truck capable barge from Lowe's

The Forum is working again - excellent!
(it appeared to be down for a while earlier today).

How much would the loaded pick-up truck weigh?
I am guessing perhaps 1.5 tonnes in total (or perhaps even allow for 2 tonnes, re extra 'loose' cargo?)

In the estimate below, I assumed a simple catamaran hull form, with rectangular pontoons (we can add shape to the ends later).
A cat because I like cats, and they can have advantages re resistance and stability, over a monohull.
Lets say that each pontoon is 1 m. wide, and the spacing between them is 1 m, giving an overall beam of 3 m.
And lets make an arbitrary decision to have no more than say 8" / 200 mm sinkage of the hulls when loaded with 2 tonnes of cargo.
We would then have :
Xm. x 1m. x 0.2m. x 1.025 = 1 (for one hull, where X is the length of the hull)

This gives X = 4.9 metres, say 5 metres for the length.

We would now have to decide on a minimum pontoon depth, taking into account freeboard when loaded, and stability.
Does this make sense for a rough first approximation?

 

An excellent first bash! Same beam as Serenity. Making the barge (Jayne) same dimensions seems appropriate. So LOA 8m, beam 3m. Adequate roll stability? In a cat, tunnel top must be moderately high to avoid slap from waves. And bridge structure has depth, inevitably. Does that raise the CofG too high?

 

Great first draft Bajansailor!

I'd prefer to see something longer than 5m.
DogC wants to make it a push barge (Jayne) so he needs an indent at the stern for SERENITY to notch into.
I was thinking 8m LOA.
Just looked up F350 weight and length:
7 - 8m long and up to 4 tonnes ... empty!
Now that's a dually but still a "pick-up truck".
Big, heavy 2-volt batteries can be the order of the day around here for "off-grid" installations.
Load 7 of those up and you've got half a tonne right there.
Include a generator, lumber, tools, solar panels, wiring, propane tanks, full 45 gallon drums, and BRICKS, lots and lots of bricks!

I'm fond of the idea of a cat barge with reserve buoyancy above the pontoons making for raised side decks.
This would allow the truck to sit lower, lowering the CoG while offering huge roll protection.

End 1/2 view:

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Geeze, I just remembered, John wants to make the barge a Sea Sled hull....

 

I can see an advantage for the barge to have a sea sled hull form if she will be pushed at say 25 knots.
But the actual logistics of doing this might be a tad difficult?
I think you had mentioned earlier that the passages would be fairly short?
A three mile trip would only take 30 minutes at 6 knots, and 6 knots should be fairly easy to do, pushing a laden barge, while not drinking a lot of fuel?
I wouldn't worry too much about bridge deck clearance on a catamaran hull form if it slaps a bit at 6 knots.
And if you want to carry a heavier cargo, then as soon as the underside of the bridge deck kisses the water, your second moment of area of the waterplane goes up with virtually no increase of displacement, so your stability improves.
I do like Bluebell's suggestion re having buoyancy sponsons above the deck on the port and starboard sides - even if the cargo shifts to one side, and the gunwhale on that side gets immersed, you will then quickly have a lot of reserve buoyancy coming in to play.
Have a nice bulwark around the bow as well, with RO/RO access over the stern - maybe have a hinging ramp, or a portable one?
If the latter, then maybe the HIAB crane (or even the gantry) could lift it into place when required?
A wee HIAB on Serenity could also be used for conventional lift on / lift off cargo on the barge (eg pallets?) where RO/RO access is not feasible?

Edit - I know that a steel shoebox type of barge is not your cup of tea, but I am impressed by the relatively low cost of this new 30' x 12' steel barge -
Barge 371 (new construction) - Lee Felterman & Assoc https://leefelterman.com/barges/barge-361-immediately-available/

Similarly these aluminium barges are very neat, although no prices are mentioned, but they could be useful for reference - some have HIAB cranes as well.
Gallery - Aluminum Barges https://aluminumbarges.com/gallery/

And these small ally barges - most are 8'6" wide, for easy trailering, but you would not have to worry about such a constraint. Again, just for reference ideas.
Life Tyme Boats https://www.lifetymeboats.com/boat.php?type=barge

 

Great websites BS!

Here's a crazy idea, make it self propelled.
Sea Sled landing barge.
12m x 3m

 

Well, another sea sled would be nice. Need a barge for Serenity though. Is that 3? Just one is tiring some days.

 

3 what?

 

3 to get ready.
4 to go.

 

I meant, if I build a barge, that is sea sledform, then I power it, it's just another sea sled with limited accommodations. So then logically, I'd need a third sea sled, as a small unpowered barge to push with Serenity.
That's 3! Woot woot! I'll tell Anne...

Ah no. No, I won't.

 

Okay, now that I know wtf you're talking about.
Focus on the one, the first one.
Let's see how it weathers sea-trials and how it does towing, and pushing before we go designing more projects.
Just saying, I find it distracting and confusing at the best of times and I'm not even building the boat.

 

Yeah. I need to put ice in my hat. My brain is revving higher than manufacturers suggested max rpm.

 

It's fun to imagine using a big piece of natural ice as a barge. Totally impractical, I assume, because icebergs sometimes turn over, and fuel requirements, and it would only stay intact under conditions when there are other large pieces of ice moving downriver to be avoided.

I assume it is the materials, rather than the truck, that need to be transported. If a motor vehicle is needed at each end, maybe they could just use two motor vehicles. Perhaps motor vehicles are already available at both ends - for rent if owning them both is too expensive for the city, and you don't need to move stuff too often. Maybe the bulldozer would work, with a trailer.

If you can split the load up into multiple trips, inexpensive small water craft might work too. Some small craft that can be paddled by one or more people at that speed by very fit paddler(s). E.g., a multi-person canoe can hold a lot. If they can't paddle the whole way at that speed at once, they can stop by the side and rest for a while. Add a small motor and you don't need fit athletes. If you need to move something bulky, like large boards, or something heavy, like a snowmobile or ATV, they can be dragged behind the boat, perhaps on a float. There are lots of people people who have built small watercraft from materials available at Lowes - though perhaps such craft are already in use in the area, so don't need to be built or bought, just leased.

Now for solutions outside boat design:

If Lowes already ships in the area by barge, would Lowes lease the partial use of their barge and pilot to transport other things at reasonable cost?

Could you move the stuff by snowmobile+sled? Perhaps on the river (when it is frozen), perhaps not. And perhaps in several trips rather than all at once, which reduces the weight requirements. I'm guessing that snowmobiles, and other snow & ice-capable craft, are already in use in the area, that can be leased, if the city doesn't already own one. I would have thought that a snowmobile (etc.) + sled solutions would be the easiest solution, rather than building your own large stable sturdy barge to transport the loaded truck.

But I know nothing about the terrain. Perhaps it is too rough or treacherous for snowmobiles and sleds. And I don't know whether they sometimes have to cross the river, and whether there is already a bridge that crosses it.

I admit that most of what I just mentioned (other than leasing the Lowes barge) assumes what you need to transport isn't too big and heavy. If you need to transport the building materials for a large building, a barge may be the only answer.