# How do those trash can truck pickup arms work? **URL:** \ **Category:** Factual Questions\ **Created:** [August 18, 2011, 2:49pm UTC](https://boards.straightdope.com/t/how-do-those-trash-can-truck-pickup-arms-work/593170 "2011-08-18T14:49:32Z")\ **Posts on this page:** 11\ **Page:** 1
**Author:** ![KlondikeGeoff](https://avatars.discourse-cdn.com/v4/letter/k/3e96dc/32.png) [@KlondikeGeoff](https://boards.straightdope.com/u/KlondikeGeoff)\ **Post date:** [August 18, 2011, 2:49pm UTC](https://boards.straightdope.com/t/how-do-those-trash-can-truck-pickup-arms-work/593170/1 "2011-08-18T14:49:32Z")
We all put out our large, plastic trash cans weekly for pickup. A few years ago, they came through with a driver and a pickup guy. He’d jump down, pickup the bin and empty it into the yaw of the truck and move on. Then they got those trucks with just a driver. He drives a little ahead of the can, and a big robotic arm comes out, grabs the can, lifts and empties it. What puzzles me is how the driver does this. Is his depth perception so good he can look at the outside right mirror and stop when it is opposite the can? Or is there some device or instrument that lets him know the proper place to stop? ---
**Author:** ![gazpacho](https://avatars.discourse-cdn.com/v4/letter/g/6f9a4e/32.png) [@gazpacho](https://boards.straightdope.com/u/gazpacho)\ **Post date:** [August 18, 2011, 3:00pm UTC](https://boards.straightdope.com/t/how-do-those-trash-can-truck-pickup-arms-work/593170/2 "2011-08-18T15:00:17Z")
The trucks where I live seem to be able to pick up the can if the truck is in the right place plus or minus a couple of feet. It does not seem that hard to stop the truck with that kind of accuracy just by looking out the mirror. ---
**Author:** ![Turek](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/turek/32/18782_2.png) [@Turek](https://boards.straightdope.com/u/Turek)\ **Post date:** [August 18, 2011, 3:47pm UTC](https://boards.straightdope.com/t/how-do-those-trash-can-truck-pickup-arms-work/593170/3 "2011-08-18T15:47:10Z")
> [@KlondikeGeoff](#): > > How do those trash can truck pickup arms work? My HS physics teacher had a canned answer whenever we asked this type of question: > [@](#): > > Quite well. 😛 ---
**Author:** ![fiddlesticks](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/fiddlesticks/32/18129_2.png) [@fiddlesticks](https://boards.straightdope.com/u/fiddlesticks)\ **Post date:** [August 18, 2011, 4:21pm UTC](https://boards.straightdope.com/t/how-do-those-trash-can-truck-pickup-arms-work/593170/4 "2011-08-18T16:21:51Z")
I always presumed those trucks have camera(s) that allow the driver to see the arm’s positioning, but I’ve never been inside one. 🙂 ---
**Author:** ![nivlac](https://avatars.discourse-cdn.com/v4/letter/n/3bc359/32.png) [@nivlac](https://boards.straightdope.com/u/nivlac)\ **Post date:** [August 18, 2011, 4:58pm UTC](https://boards.straightdope.com/t/how-do-those-trash-can-truck-pickup-arms-work/593170/5 "2011-08-18T16:58:48Z")
You lost me at “yaw”. 😛 Anyhow, the question led me to youtube to see garbage trucks in action [here](http://www.youtube.com/watch?v=06xpoVe6ZoQ)and [here](http://www.youtube.com/watch?v=-w6uIDEbNX4&feature=related). I knew there must be different types of garbage trucks, but I never realized there are so many types! Strangely, the videos held me spell-bound watching garbage being picked up. Where I live, the garbage pickups are done by trucks that require a human assist to shove the bins onto the pickup arms. Complete automation is not used, maybe because we have a lot of hills in the city. ---
**Author:** ![Drunky\_Smurf](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/drunky_smurf/32/449_2.png) [@Drunky\_Smurf](https://boards.straightdope.com/u/Drunky_Smurf)\ **Post date:** [August 18, 2011, 5:19pm UTC](https://boards.straightdope.com/t/how-do-those-trash-can-truck-pickup-arms-work/593170/6 "2011-08-18T17:19:28Z")
I can get how that type of truck and driver could pick up a can when there is nothing around it because the claw is spread out a few feet and then closes around the can so the claw doesn’t need to be that accurate. What I wonder about from what I see in my neighborhood is people put their trash and recycle cans within inches of each other and when I get home I see the cans are only a foot or two apart so what I wonder about is how can they be that accurate to grab a specific can when the claw is so spread out before it closes around the can? ---
**Author:** ![johnpost](https://avatars.discourse-cdn.com/v4/letter/j/f17d59/32.png) [@johnpost](https://boards.straightdope.com/u/johnpost)\ **Post date:** [August 18, 2011, 6:39pm UTC](https://boards.straightdope.com/t/how-do-those-trash-can-truck-pickup-arms-work/593170/7 "2011-08-18T18:39:39Z")
there are claws for some systems and hooks (grabs the hinge) for others. hooks can grab close packed cans. ---
**Author:** ![KlondikeGeoff](https://avatars.discourse-cdn.com/v4/letter/k/3e96dc/32.png) [@KlondikeGeoff](https://boards.straightdope.com/u/KlondikeGeoff)\ **Post date:** [August 18, 2011, 6:42pm UTC](https://boards.straightdope.com/t/how-do-those-trash-can-truck-pickup-arms-work/593170/8 "2011-08-18T18:42:16Z")
Well, I see that it is still a mystery. I suddenly :smack: thought, why don’t I call the company, named Waste Management, and ask. Well the rep I got had no idea either. He offered to put me in touch with a supervisor, but said they never ride the trucks, so he probably would not know either. I was too embarrassed to go that far, so gave up. BTW, the old Phoenix Open golf tournament sold the name rights to them, so it is now the Waste Management Phoenix Open. That always breaks me up. ---
**Author:** ![zombywoof](https://avatars.discourse-cdn.com/v4/letter/z/9e8a1a/32.png) [@zombywoof](https://boards.straightdope.com/u/zombywoof)\ **Post date:** [August 18, 2011, 6:53pm UTC](https://boards.straightdope.com/t/how-do-those-trash-can-truck-pickup-arms-work/593170/9 "2011-08-18T18:53:56Z")
I don’t know, but I’ve always assumed the drivers in my area have a little monitor where they can see a camera feed of the cans/arm - they seem to have a joystick control for the arm, making the whole setup like a little video game - though maybe a properly oriented mirror would work well enough. ---
**Author:** ![The\_Evil\_Prince\_Zorte](https://avatars.discourse-cdn.com/v4/letter/t/e95f7d/32.png) [@The\_Evil\_Prince\_Zorte](https://boards.straightdope.com/u/The_Evil_Prince_Zorte)\ **Post date:** [August 18, 2011, 7:07pm UTC](https://boards.straightdope.com/t/how-do-those-trash-can-truck-pickup-arms-work/593170/10 "2011-08-18T19:07:32Z")
The cans in my neighborhood have a metal bar on the front that I assume is compatible with some kind of hook, though the trucks don’t use it. They can pick up cans close together with the claw. They just close it to a little wider than the can before extending, so it slides in between the cans. The arm can adjust side to side so they don’t have to park in the exactly the right spot to line up with the can. As far as doing it all in the mirror without any guides, it is just a matter of practice. The whole process probably feels automatic to the drivers who have had tens of thousands of pickups. They are pretty cool in my city, they will get out of the truck to roll out the cans for senior citizens or the disabled. If I have too much yard waste to fit in the green can, I can wait until the garbage can has been emptied, then fill it up with the overflow. When they come around for the green can, they will empty the black one too if I have left some weeds hanging out for them to see. ---
**Author:** ![boytyperanma](https://avatars.discourse-cdn.com/v4/letter/b/4491bb/32.png) [@boytyperanma](https://boards.straightdope.com/u/boytyperanma)\ **Post date:** [August 18, 2011, 7:14pm UTC](https://boards.straightdope.com/t/how-do-those-trash-can-truck-pickup-arms-work/593170/11 "2011-08-18T19:14:26Z")
See as the alternative to successfully grabbing the cans is typically knocking them over and having to pick up the mess, the drivers get pretty good at it quickly. Some trucks have a camera or a sensor package, the sensor packages tend to fail quickly so the companies don’t bother fixing them. The Camera gets used by newer drivers but once the drivers have the hang of it they don’t use them much. The process is simple drive next to can, pull forward till the can is in the claw, hit the button. The claw automatically picks up the can, dumps it, puts it down, then swivels out of the way so the truck can continue forward, by the time he’s approaching the next can it’s swiveled back in position for the next can. After doing the process hundreds of times the drivers simply have the approach and stopping time down pat and don’t have to put much thought into it.