3 ms·
The story discusses, and dismisses, the option of incorporating magnetic sweeping into regular street-sweeping operations, though I find the argument unconvinci
by dredmorbius 3y ago
The story discusses, and dismisses, the option of incorporating magnetic sweeping into regular street-sweeping operations, though I find the argument unconvincing.
If your goal is to pick up loose ferrous material (much of which incidentally turns out to be dust, some of which is apparently meteoric in origin), you don't need magnets which are capable of yoinking a manhole cover or sewer grating out of the ground. An array of magnets, periodically wiped into the normal trash flow, should do the trick. (This is a case where electromagnets rather than fixed magnets are probably superior.) A fancy-pants solution might use GPS and GIS to note locations of known ferrous infrastructure (grates and the like), though it seems to me that simply by tuning the magnet's strength and reach it should be possible to, say, lift a few grams of nails or tacks, whilst leaving the 100kg+ covers and grates in place.
(There are a few smaller utility openings, though I suspect those are rare, as street furniture generally needs to Not Move whilst being trampled by autos, lorries, busses, etc.)
This is of course aside from Atlanta's apparently quite stingy sweeping schedule, another matter.
- aaron695 3y ago[dead]
- ornornor 3y agoI wonder if the problem is that it would lift grates up or rather pull the trailer down/crushing the wheels or just immobilizing the bike from the attraction to the grates while not being able to lift them up.
- dredmorbius 3y agoMagnets incorporated into a traditional street-sweeping truck shouldn't be bothered by street fixtures, unlike a on a bicycle. I can see how the bicycle approach might experience challenges, but even there I think the problem isn't particularly severe. Switchable electromagnets which could automatically sense a large ferrous object (e.g., grates, covers) and deactivate or reduce strength over them might be another option. A filtered reply to my earlier comment argues that electromagnets are "massive with generators". This ... is seriously misguided. Electromagnets can be tiny, you'll find them in small motors (electric toothbrush, the haptic vibrator in your mobile device). Given extant electric capabilities of a streetsweeper, a modest grid/array of magnets would be trivial to implement.