Spacing Issues

I am an architect that was asked to design a dumpster pad for a project and am trying to figure out how big of an area i will need for trucks to manuever. The area has to be fenced off. I just have a question about turning radiuses and backing up. What is the average turning radius for a truck? and does a truck need to completely straighten out before you can back up to the trailer or can you back up at an angle? and if so to what degrre of an angle can you back up at?

 

Tough question to answer effectively. One thing ... are ALL types of trucks, tractor-trailers going to need egress in/out (53 foot trailers)? ... through the same access lane? The turning radius, while important, is not as key as the length of the trailer(s) that will need access (trailer tandems to drive tandems length). I'd say, as a general rule, if the driver will have to "turn around", at some point he will need to be able to "get straight" before backing so as to be able to reverse his trailer direction and/or back into a "dedicated slot" (potentially requiring much more real estate). But without seeing a diagram of the situation, it will be hard to answer you. In some situation there may be more than one way to design the plan (to skin a cat) and the less real estate you have to work with, the more difficult it will be for drivers, regardless of the tactical maneuver required. Sorry I can't be of more help. Honestly, I've know of some lot designers who didn't have modeling software would go to truck stops and purchase real-scale model truck(s) to get a sense of what would be required and set up there own little scale world. The actual turns and backing maneuvers don't quite behave as in reality, but you can get a sense.

 

The image that I have is a pdf so i am not able to upload but basicially it is a dumpster pad with 40 yard rolloffs. This is a basic diagram i tried to do in paint. The blue dotted line is the proposed fence which can move based on the trungin radius. But they would like to use as little room as possible.

 

Well, then basically it comes down to

What types of trucks (overall length) are we talking about that might need to negotiate the turn. If we're ONLY talking about "straight truck" configurations (no trailer, short or long) that typically move roll-off's like I'm familiar with ... where the first fence line would be would have some to do with the width of the "truck entrance gate". With straight truck configurations, you have to allow for "tail overhang swing" in tight turns. If the gate is wide enough --and the gates are not in the way--, it will allow for a lot of flexibility in initiating the turn, but if it's a narrow gate (under about 12 foot, say) this is going to probably require you to add some more distance to the fence because he will have to proceed a bit further before beginning his turn ... then the location of the fence leading up to the fence line you're concerned with also becomes a potential issue if it's not well offset of the exit post due to tail swing of straight trucks with long overhangs. I'd want a 3 foot exit minimum (5 foot preferably) offset from the left gate post (left when exiting)

If I had to provide an estimate, I'd say you'll should look for the distance from the front bumper of the vehicle to the center of the drive tandems (assuming straight truck) PLUS an additional 15 feet. However, if the fence coming out of the exit is too close to the exit path, tail swing may also be an issue here too in a hard right turn scenario as was discussed earlier.

But if we're talking about combination vehicles, (65-70 foot tractor-trailers) may also need access/exit, the entire game changes and disregard everything I've said.

 

Also, as per the diagram, a lot has to do with what "attitude" the driver can begin to proceed through the gate. i.e. will he have to proceed (begin) at a right angle to the gate opening or can he "cheat it" a bit and begin through the gate with a 10-15 degree "head start". I guess one would have to assume a right angle (to the opening) would have to be maintained leading to the gate opening.

 

The thing that is going to give you trouble is keeping your large roll-offs near the fence like that. If the driver was to ride along the fence and then try to line up for that slot more than likely he'll be on a 'blind side' backing move, never a good thing. If you end up having more larger roll-offs in the area between the exit and the "IN" gate that takes away his turning area.

As STexan mentions and I believe you're talking about single-body trucks too, they have to have much more room than a tractor/trailer setup.. and less if it's a day cab (presuming that's what you're running also)... so I'd say go look and have a driver show you what he needs. A good rule of thumb is figure you'll need at least 2.5 times the longest truck (single body/tractor-trailer) that they intend to use in that yard.

Is that exit open or is it fenced also, can't see from the drawing. If it's open and a driver can use that room to the street too, that helps, but otherwise it looks to me like they're trying to secure the yard....meaning it's enclosed.

Best thing to do is setup parking so drivers can back using driver side and that layout right there is preventing that naturally so you're going to need to use more room to accomodate blind-side backing.

 

I use to haul rolloff and many places were tight. The approach makes a big difference. If the boxes are parallel with the entrance you can fit as tight as 60'. The standard box is 8'x22'. Most trucks are around 30'-32'.

Boxes perpendicular to the exit you need about 75'. Then you need to figure if the place needs to open the back gate of the box to get big items in there. You need another 8' for door swing.

I would make it an even 100' on your drawing and everyone would be happy. Leave enough room in between the boxes to load it with what ever equipment they are using.

You don't necessarily need a separate entrance and exit either. On your drawing one gate off to the left in the middle to end would be sufficient.


Is this an exclusive dumpster area or something that is going to be set up beside some docks?

 

I have some DWG files for truck radius' from civil engineering classes if you want them. Covers everything from a straight truck to a 53' semi.

I can't upload them here.

 

I would absolutely love that. If you don't mind emailing it my email is xxxxxxxxxxxxxx

Edit by CC: Sorry, no email addy allowed. Please PM

 

Easy way out - find a similar area already in use and measure it .