isn't the whole point of a shuttle buggy to keep the paver paving the road continuously. and to allow the dump trucks to dump there load right away. so why would the trucks sit there and build a line up like you see when a shuttle buggy isn't being used? i was watching a crew pave a street the other day and they were using a shuttle buggy. they paved one lane then backed everything up to the beginning of the first lane, as opposed to just starting the second lane in the other direction. while the paver was setting up again the 2 dump trucks that showed up were just sitting there. the first one waited until the paver was ready to start moving to dump its load into the shuttle buggy. after he dumped his load the next dump truck waited until the paver and buggy had progessed a little bit to dump his load. then they ran out of trucks and the paver had to stop. from what i've read i thought the whole point of the buggy was to keep the paver moving continously which creates a better road. by avoiding segregation (i think thats the word) and keeping the screed from settling (think thats word the roadtech website used). it's also suppose to keep the trucks flowing instead of sitting and waiting to dump. because they can dump right away into the buggy.
The other point of a shuttle buggy is to eliminate the truck contacting the paver and moving the screed and screwing up your ride quality numbers.
doesn't the truck just stop a few feet before the paver and shift into neutral, being pushed by the paver in a situation like that? thats what it looks like anyway. it actually looks like that with the shuttle buggy too.
Yeah it probably is, but there is no physical contact between shuttle buggy and paver. The desegregation of the asphalt and temperature remixing comes from the auger at the bottom of the bin in the shuttle buggy. That auger is (patented?) designed to pull from its "bin" of asphalt from three seperate locations meaning that the temperature and mixture is as mixed and even as possible. While I don't see it reducing the number of trucks, it helps make the flow of material into the paver and the paving itself go more smoothly... assuming all your trucks show up at the right time of course.:Banghead
i don't know that it would reduce the number of trucks, although the roadtec website claims it will. maybe the website puts on there it's intended use. i thought it was suppose to allow the trucks to dump there load right away. instead of waiting like they do when only the paver is used. with the shuttle buggy able to hold so much asphalt at once, after one truck dumps the next one should be backing up and dumping it's load. but the other day when i watching them pave, the operation was just as if the buggy wasn't there. there were 3 trucks lined up at once and none of then had dumped yet until the paver was ready to move. then the first truck backed up and started dumping its load slowly like when just a paver is used. after he pulled away the next truck waited until the buggy and paver got closer to him. the way i thought the process should is as follows first truck dumps load into buggy, pulls away, second truck dumps load into buggy, pulls away, third truck dumps load into buggy, pulls away, all while the paver is constantly moving forward paving the road.
in theory that would work, but eventually the buggy and paver hopper(insert) are gonna be maxed and then the trucks will be feedin the paving train just the same. At this point, it's the mixing and lack of "contact bumps" that the buggy makes it's money. At least that's how I understood it:beatsme
That's correct the shuttle buggy gives you a (approximate) 15 to 25 ton buffer so you keep the paver moving at all times. Once you fill that excess capacity in the SB it doesn't really save you any trucks.
could you slow the rate the trucks come when you max out the SB and paver hopper? or the amount of trucks being used? how would you max out the SB and paver hopper if the paver train is constantly moving?
Yes technically you don't need to run as many trucks. The big problem with trucks is they bunch up, but the SB allows them to dump right away and then head off for more. Normally they would have to sit and wait and dump slowly into the paver. Of course if your timing gets messed up or you have too many trucks then the paver and SB will be full, and the trucks wait until there is space to dump.
but again how do you fill the SB and paver up if they are constantly moving? if they are constantly in motion they are constantly laying asphalt. which means the material is constantly moving through the SB into the paver hopper, through the paver and onto the road.
The mixing chamber acts as a holding/buffer zone the quickly unloads the trucks while allowing the paving operation to move continuously. You have to think of it as the first truck simply charging the system, then each additional truck feeds the system to allow for paving. In michigan we run flowboys with about 40 to 50 tons of material on board so it doesn't really eliminate any trucks and the trucks still have to spend some time in the SB because the sb's don't hold that much material.
Well it all needs to start with that trusty thing called a calculator! How many rollers u have to do the job. Remember they r only 85% efficient. Thats where some of your speed comes into play. How fast is the paving spec? How much can ur plant make efficiently an hour? How many trucks do u need to make a complete round? And when all those #'s are in sink you have yourself a well oiled paving train! As for the buggy we wait on the third truck to show up every morning before take off. Sometimes the third truck is used first cause its about the hottest your gonna get first thing in the morning. We fill the box with the first truck, auger the screed full and when he starts to dump the second the paver moves. After that we dont stop till the last ton is on the ground, if there are no break downs..LOL If u start at 6am u should have 2800 ton in 8 hours. Thats an easy 350 ton an hour. Once the paver speed is set it never changes unless there is a problem with compaction or something else serious.
but if the SB is constantly dumping it's material into the paver it seems the only time it would be completely full is right when you start the train. after the train is moving it would constantly be moving material and constantly need fed. so there should be no reason using regular size dump trucks a SB and a paver that those trucks would need to wait any lenght of time to dump there load and no reason the paver should need to stop. i know calculations need to be correct but it seems paving companys should have this down already, except for the unseen problems.
Lots of things work perfectly in theory pulling it off in real life is a different story. I personally like windrow paving better.
Sounds like they didnt order the right amount of trucks. Maybe? We usually have 2 or 3 in front of us, most of the time. But they may only be there 5 minutes or so. Our trucks in Illinois can only legally haul 21 ton around here, so in other states they may be a factor on how long the trucks sit there. Our opetators only turn on C1 (conveyor 1 on the SB) when they can hold and are able to dump a hole truck. Dont really know what was going on here. I wasnt trying to get smart. It kinda looked like it after i just reread my post. I know if the SB is ran correctly we can never live without it..
that was the first time i've actually stopped and watch a crew pave a road with a shuttle buggy. and from what i've read and know about them it just seemed they weren't using it nearly to it's full potential. as i said it was almost as if the shuttle buggy wasn't even there. i know it was mixing the asphalt which prevents segregation but there are so many more benefits to the shuttle buggy than that.
We use our buggy in front of the Road Widener too.. Now thats production.. LOL
The buggy is meant to provide consistent asphalt to the paver. Ideally you don't want mix to spend much time in the buggy. The heat is best retained while the asphalt is in the truck and tarped. The buggies can usually only hold 1 truck load of asphalt so its not the best "hopper". Finding someone to run the thing that can balance following the truck on one end, and keeping the conveyor feeding the paved inside its hopper is not so easy. The buggy does help with everything that has been mentioned also, but so far as the state is concerned its primary function is for anti segregation. They also might be waiting until the paver is ready in case something breaks down. I also noticed that the buggy gets really heavy when its full and can cause sub grade issues if its left loaded in one spot for too long (on crappy sub grades).
from what i understood i thought it was just the oposite. the asphalt is better in the buggy because it has the augers to mix it up and prevent segregation. sitting in the dump truck the heat isn't distrubted evenly. according to road tec's website the buggy should eleminate the wait time dump trucks spend on site. i can't remember how much they said the buggy holds but they make it sound like each truck should be able to just arrive on site and dump there load almost immediately. i think whats on roadtec's website makes sense. once the paver starts moving asphalt should always be flowing. so the paver should never be completely full and neither should the buggy. so the trucks should just be able to dump there load upon arrival. maybe thats in a pefect world though...........
Well we usded the buggy again today with the road widener. We laid 700 ton in 4 hours in a one mile section... Gettin er done! lol
the asphalt in the buggy isn't always being mixed....... it is agitated prior to being fed into the hopper of the spreader, but thats about it. A truck can unload into the shuttle buggy faster than the buggy can unload to the spreaders, not to mention if there are two and he has to re-position. often production is governed by the capacity of the rollers to keep up, not so much how fast the spreaders can lay the asphalt. the main benefits we use MTV's here are: 1) to prevent end-dump segregation, as the asphalt gets mixed prior to going to the spreader, there isn't a lot of re-heating done in the shuttle buggy, but mixing the hot asphalt with the almost hot asphalt gives you better consistency. most trucks here run with insulated boxes, and run the exhaust out the box as well to keep 'er warm. 2) eliminates trucks backing up to the spreader and bumping the screed which can affect the ride quality 3) allows contractors better production when running more than one spreader on a job and helps to eliminate joints, the shuttle buggy feeds the spreaders a lot easier than trying to squeeze 2 flow-boy's side by side! Just this weekend we put down 2600 tonnes in one day! 2 Roadtec spreaders and a shuttle buggy, giddy up! They had some tight spots on this job, where the road would narrow from two lanes down to one and a half, using the shuttle buggy allowed the 2 spreaders to continue on and eliminate a joint, there would have been no way to do that with backing trucks up! sorry for the rant.... i'll post pics of that job soon!
yes i would love to see pictures of that. i don't ever see 2 pavers running side by side. usually around my neck of the woods they do a lane at a time with one paver and a shuttle buggy. they do the right lane and then go back the other direction to do the left lane. i'm not really sure why on the highway they don't pave the entire 2 lanes at once. other than to keep traffic apart. those screeds will widen to the full width of 2 lanes.
Well we are going to try a new use for the shuttle buggy. How about using for an asphalt curb machine? My boss is nuts. I get to be the operator. Its gonna be hard to fun it and take pictures. $375,000 machine feeding a $2,000 machine.
I've got a $4000 one if you want to try that instead We seriously need some pictures of that one.
We have tried it down here a couple of times. Make sure you close the rubber end of C3 off a little before feeding the curb machine. Yiu will be surprised how good it works and how much manual labor it saves. Post pictures
Well it only took an hour to go up one to back down. I can tell u it worked great. Its much easier to back the buggy and dump in it than to drive forward. This way u dont have to steer and move c3 when your not driving to straight.
:notworthy :notworthy :notworthy That's awesome :notworthy :notworthy :notworthy