Stone Boat Design Principles?

[IHDiesel73L]

I've checked around and there are plenty of threads on stone boats here, but I have some questions that are somewhat specific to my conditions. First, I've seen stone boats both with completely flat bottoms that fully contact the ground like a toboggan, such as a 3/4" sheet of plywood with a frame bolted around the edges, and I've also seen boats with two (or three) runners made from 4x4s, etc...similar to the old steel runner snow sleds or sleighs. Obviously the first design spreads the weight out more and probably allows the entire assembly to float over softer ground, but the greater contact area probably also creates more friction or drag. The second design has much less contact area and perhaps more friction, but definitely much more ground pressure on the two narrow runners. In my particular case I am looking to pick boulders from a stone row that runs along our mostly flat gravel lane in order to build a small boulder wall along the part of the driveway where we park next to the house as I plan to pave it with asphalt next year. I'm going to set the boulders in the ground a bit so that the asphalt can run right up against them with the goal being that the edge of the pavement is supported so that it doesn't begin to break up over time. None of the rock I'm planning to move is particularly large but TBN standards :laughing: The largest rocks are probably in the neighborhood of 1,500 to 2,000 pounds (4' long, 2' wide, 2" thick average), so they could be moved in an FEL bucket, but I am currently tractorless. I can borrow my neighbor's pretty much anytime, but this way I don't have to bother him, and I'm sure I could find other uses for the boat. Which brings me to my next question-how well do you think my 2012 F-250 4x4 6.2L gas would do pulling a stone boat? I Googled a bit and found pictures of old school truck and tractor pulling with stone boats which is still done in some parts of the country where they basically just load up a boat with increasing levels of concrete weights to see who can pull it and how far. I'm currently running nice wide 305/70/17s which I will air down.

Here is a picture the lane:

 

[jmc]

Pure frictional force is independent of surface area, all other things being equal.

When adhesion is involved, surface area matters, ie racing slicks. Probably not a factor here.

If there isn't enough area to support the load, then you have friction plus mechanical interference.

I'd go with a full surface contact. I wish I had the ancient car hood we used for a toboggan. It had a big lip in front and a gentle curve on the sides, which would be good in turns. About twice as thick of sheet metal as today's.

 

[oosik]

That's exactly what I was thinking - an old car hood. Back when all the land was homesteaded around here - 1890's - several fields were cleared - rock walls were built. There is an old stone boat on the adjoining property. It looks like an overgrown dog sled. About 6 feet wide and 14 feet long. Two runners with steel strapping on the runner bottoms. It was set up to be pulled by a team of - ?? ( mules probably ). The neighboring homesteader was said to have five sons. Based upon the miles & miles of rock walls - no doubt what these five sons did. A picture of a short section of one of these walls..........View attachment 663935

 

[oosik]

Your truck will have no problem towing a rock boat. But I would recommend some type of wagon. You won't be able to back up with a rock boat - a rock boat will likely tear up that grass lined driveway. BTW - exactly how do you plan on moving a 2000# rock into the rock boat or a wagon, for that matter. If you have access to a tractor & FEL - and it's big enough - negotiate for it's use and FORGET the stone boats, etc. Pick, move, place with the tractor & FEL. The only thing better - a larger tractor and grapple.

 

[/pine]

Sorry I didn't read the entire OP's novel....but my advice is just go (to the junk yard) or out back and get the hood off one of the yard ornaments...inverted vehicle hoods make great stone boats etc...

 

[Captain Dirty]

...inverted vehicle hoods make great stone boats etc...

The probability of finding a 1950's or earlier automobile hood (when hoods had the prow that made them such good sleds) is remote. A home fuel-oil tank with the ends cut away and cut in half in a longitudinal vertical plane would have two upturned ends to facilitate dragging in forward or reverse direction. But I'm with Oosik; if the neighbor's tractor will handle 2000+ lbs., be it with grapple, forks, or a sling from the bucket, borrow it. The bottle of high-quality booze or whatever favor you use for repayment will be far easier than the manual work with crowbars, come-along, etc. to position the stones on the sled and to place the stones in the wall.

 

[lennyzx11]

I had one I made with 3/4” plywood and 4x6 runners. Toboggan style. It lasted for years. Rocks weren’t that big though. Less than 500 lbs probably. It was all I could do to get them rolled and slid onto the sled

I used a rear mounted dirt scoop on a 9n for a long time after that.
Back up to rock, drop scoop and back under it. Pick up and drive to spot and place it close to where needed. Set in the ground, trip the dump and pick up and drive away.

 

[IHDiesel73L]

The probability of finding a 1950's or earlier automobile hood (when hoods had the prow that made them such good sleds) is remote. A home fuel-oil tank with the ends cut away and cut in half in a longitudinal vertical plane would have two upturned ends to facilitate dragging in forward or reverse direction. But I'm with Oosik; if the neighbor's tractor will handle 2000+ lbs., be it with grapple, forks, or a sling from the bucket, borrow it. The bottle of high-quality booze or whatever favor you use for repayment will be far easier than the manual work with crowbars, come-along, etc. to position the stones on the sled and to place the stones in the wall.

I agree on the hood-an oil tank would be far easier to find. With regard to the tractor, its an old Kubota L245DT. It will pick up 2000lbs in the bucket but it doesn't like to-plus I'm guesstimating. I did some searching and found that granitic gneiss weighs about 185lbs/pcf. If I'm wrong or if I happen to see a boulder that weighs more I don't want to end up breaking someone else's machine. Since all of the boulders I'm looking for are conveniently perched along the lane my plan was to coax them as close to the edge of the road as possible with a combination of working the bucket curl and back-dragging. The roadbed sits lower than the edge of the road from plowing, etc...so from there it shouldn't be too hard to roll them onto the stone boat. From there it's a straight and slightly downhill run to the driveway where I'll probably just pile them until I grab the tractor again and use it to place them neatly.

 

[lostcause]

I clicked on this because I was curious whether a stone boat was similar to a concrete canoe... boy, was I wrong...

Never used it for stone, but I did cut the ends off a 275 gal oil tank and unfold it to haul very large stumps that my tractor bucket wouldn't pick up. same principle and it worked good.

 

[Woodeye]

I have a 1/4” 4 X 8 foot sheet of steel with a 6 Inch lip bent on the front. I’ll use it once in a great while in the summer. On snow it slides too well, I’m afraid I’ll ruin a tire. I don’t use it enough to justify building a tow bar but that would be great.