Accidental Ammo August 1, 2015

I must admit I was stunned at how much force those rocks were flying with. I would never have guessed that they would be so damaging.

The city I live in has an ordinance: if you have an alley behind your structure, and there is grass growing in that alley, then you are responsible for mowing it.

US Highway 190 has run through the middle of town for decades now (I don't care if the bypass is the "new" 190; I'm sticking with the old name). When it was first run through, it was fairly narrow. As a result, the city was able to establish empty lots between the highway and the handful of residential streets that jutted off of it. But back around the 1980s, traffic got so intense in places that the highway had to be widened. This process caused the lots to be paved over. Despite this, the city insisted upon having some sort of barrier between residential properties and the highway.

Well, by the grid system that was in place during the 1950s / 1960s, the highway was 000. The 100s block of any side street was immediately adjacent to the highway. The 200s block came next, usually after another road. Then the 300s, 400s, et cetra (if a road ran that long).

My late maternal grandmother's house was #103 on her street, meaning that she was two houses over from the highway. We never minded it, but the city used the "need for a barrier" as an excuse to go "eminent domain" on #101, evict the family living there, and sell it to a contractor. The contractor bulldozed the house and replaced it with a parcel service office. The company promised that their trucks would never use the alley behind the block, but as soon as the facility was operational they went back on their word.

The alley had never been paved, and so fully 50% of it was dirt. This meant that whenever I went to mow the alley, I was forever kicking up rocks with the mower. The guard helped to funnel the rocks aside, but if you were in the wrong spot you could still get a nice gash. Once the trucks began running down the alley, however, the alley deteriorated to the point that it eventually became about 60% - 70% dirt. This led to the unfortunate situations of my having to mow while dodging trucks and the increasingly large rocks that were coming up as the trucks wore the grass away.

We informed the city that the situation was now so dangerous that we could not mow the alley; unless the city forced the parcel service to keep it's promise, it just wasn't safe back there.

The city responded by threatening to fine us for not mowing.

The trucks still ran.

So yeah - I know all about massive projectiles getting kicked up.

I have a basement window that fell victim to a rock discharged from under a riding mowing - with the discharge chute attached. It was definitely an eye opener for my kids, they now more fully understand why I want them in the house or on the opposite side of the house (in the front yard when I'm mowing the back and vice versa).

Also, I go to teach my 8-year-old daughter a little bit of elementary physics when Adam was discussing the energy of the bullet vs the energy of the rock. I introduced her to the difference between Kinetic Energy (KE) and Potential Energy (PE). She grasped the concept that while she was laying on the couch, she has PE; but, if she fell off the couch, it would become KE. We'll get into the math behind them another day...

In regards to Jamie's "Mower from Hell", I think they may have actually gone too far into the 'ramping up' process on this one. He put 50 lb blades onto what appeared to be the stock 1" shaft...not surprised it failed. Should have put a beefier shaft in place.

monobor chlorate would solve that problem.

I was at my son's house and we re-watched that episode last night. Taking a closer look at where the shaft failed (we actually still framed that), it looked more like a fatigue failure rather than a torsional failure. Probably caused by excess vibration because the blade was not balanced well enough.

Also looking at Adams expressions, I think that he was really a little afraid of what just happened. It created a very dangerous situation that was totally unexpected and someone could have been killed.

imbalance was also my first thought, because it broke BETWEEN hitting things.

No arguments on the lawnmower conclusions. Science well done.

On the glass guillotine, however... Already when they began making the dummy, I was thinking, "why aren't they putting bones in there?" It's one thing to slice through "meat", but something else entirely to cleanly split bone.

I suspect the reason is they didn't want to spend too much build time and material on it, because they already knew what was going to happen. As Adam pointed out before they even made the first drop, window glass doesn't have sharp edges, so a clean cut was more or less out of the question right then and there. Also, pointed out after the first drop, windows made for highrise buildings are made of tempered glass, so there wouldn't even be shards when it broke.

But still... When they used "normal" glass with frayed edges, I think Adam was a little quick to call the dummy "cleft in twain". The glass hit the shoulder and cut off an arm. Yes, technically, "cleft in twain" is correct, because the term just means split in two and not necessarily in half, but he gave the impression early on that "half" was what they were going for. Also, this is where bone comes back into the equation. Would the result have been the same if there had been a skeleton inside the dummy?

Seems to me like they rushed through this one. They did three tests and one was a clear miss that didn't even hit the dummy. As breesfan says, it would have been nice to see what happens when tumbling glass hits a person, but they didn't even go for that, so I have to ask: If you're not going to do it right, why do it at all?

I suspect it was a combination of the astroturf being loose, which allowed the suction from the blades to lift it, and the trail of rocks helping bunch it up.

Lawn mower mayhem.
I have hit a few chunks of the harder stuff with my large fly-mow hover mower in its time.
Thankfully, the underside is shaped as a dome, and anything coming off the blade is defected downwards into the mud, which as a bouncer, if it exits the side, is a lot slower and devoid of much of the energy having been absorbed by the ground first.
However it does sting if it comes out the back and rasps your ankle, so I wear boots and heavy jeans when mowing....
But....
I suggest I have an older motor about physically three quarter the size of one of Jamies beasts, so maybe less than half the power. (Its a plug-in mains powered 240v A/C motor)
I know it will shred a cabbage with ease, but suspect it may stall on a whole water-melon.
Even so, I have a new respect for the thing.

But I do have a garden shredder.... this think will shred branches up to two inch thick without breaking stride.
I wonder what a stone flying off the rotating blades in that would do if the safety cage failed...

I have new respect for garden power tools.

The rip-a-carpet thing...
May I suggest that on the ride-on mower, if it caught an loose edge on the carpet, it would just pull it up, and that is why it was such a total shred on the test.
Having stones fly with power in all directions may have punctured that carpet and created a few loose edges underneath?... the blades on a mower are often designed to be at an angle to pull up the grass to get a decent cut?...
I dont think they glued the carpet down that well.
Turf, you aint supposed to mow turf that much when freshly laid to give the roots time to bed in to stop that happening.


Mowing public spaces.

If you own the ground, in UK, you are responsible for its upkeep, and must make it "passable" for public if it is a public footpath.
If it is not a public right of way, you are supposed to keep it "tidy"
If you dont own it, you can not be held responsible for its upkeep, thats the councils job.

As for mowing any public place, "Elf and safe tea", you must use suitable safe equipment, and as the public are not sort of expected to be able to own such expensive equipment, requiring them to do so is counter productive.

Trucks using a public highway ..
The highway over here must be metalled if its public access or works access, again the Councils job, if the trucks are not supposed to use that as an access point, they can be banned by the council.
The road must be suitable for heavy goods, or have signs stating unsuitable, with a weight limit.
Trucks using an unsuitable road surface over the weight limit are breaking the law.
Especially if the are passing close to domestic property and making noise and nuisance late at night.
If they are degrading the road surface, the company owning them may be charged with repairing the road.
If the road is privately owned, the owners have the right to deny access to anyone they wish.
They also do not have to provide a suitable road surface.
If it is a footpath with public access rights, it must be kept suitable, but then only to foot passage, not vehicle.
I am not aware of any vehicle access rights by Public over Private land.
As in, you may b granted access, by the owners, but you do not have the right to demand vehicle access at any time.
Except emergency vehicles, of course... but would anyone refuse an ambulance parking on your lawn if they were saving your life?... I think not?...