gps

[john345me]

seen alot on the rail work on small komatsus and cats

[john345me]

http://www.youtube.com/watch?v=OMaycSzR7U0 check these out

[Deas Plant]

Hi, John345ME.
You are partly right about the GPS system on a machine. There IS more to go wrong - stuff up - give trouble - etc..

How-wevver, there is absolutely no contest between a bare machine of any type and that same machine fitted with a good working GPS and being run by an operator who knows his GPS system operation. There is one bloke working locally here on the Gold Coast who is running a D6N with an after-market PAT blade, rear rippers and a GPS system. Give him an elevating scraper or two to take his spoil away or bring fill in, plus a compactor, and he will cut a complete sub-division down to sub-grade level +/- about 30mm, batters done, footpaths shaped, turns radiused, even driveways cut, ready for underground services and a grader to come in and finish the roads - - - - - ALL without a peg in sight.

You can fit them to pretty much any earthmoving machine with the same sort of accuracy, including excavators. I ran a D8N with an early GPS system fitted a couple of years ago. The job had one excavator with GPS fitted and he was mostly doing detail excavation. My job with the D8 was to do any ripping that might be needed, keep the fills in shape with the GPS and check the cut levels and locations for the other 2 excavators doing the bulk excavation. If they were a bit high, I had to cut off the excess and push it forward to them to leave finished product behind me. If they were a bit low, fill it back up and get it compacted. Between the two GPS machines, there was virtually no surveying until we got down to boxing out the roads.

Another big plus is that you can cut and fill to footpath-subgrade levels without any surveying before you have the undergrounds people come anywhere near the site. This means that they only have to move the bare minimum of material to do their job and, if they also have GPS and know how to use it, you still haven't done any surveying.

Surveyors probably make fewer mistakes than most other people on construction sites but they still cost. If you can eliminate or reduce that cost, it makes for a cheaper job.

The hardest part of getting older operators to use GPS, or any electronic grading system for that matter, is getting them to watch the monitor instead of the blade/cutting edge. I know I have cut some pretty close grades in the past without elctronic monitoring/control, even surprised myself a few times, but there is no comparison between that and KNOWING exactly how far to cut or fill and being able to come out right on target.

Just my 0.02.

[dewets]

Hi all,
I got a video from Graham Miller shot during construction of the Baldock Bypass, and they also had GPS on the dozers. It shows some of the operation from the operator's seat. Very interesting for me as a non-civil non-construction guy (I only used a D4 6U with bulldoser years ago on a farm), and even more exciting when I actually drove through the bypass in September last year.
In the IT business we've a saying: To err is human, but it takes a computer to really foul things up!

[Deas Plant]

Hi, Dewets.
So you now have a different appreciation of how the job might have been done? Good stuff.

You would probably also be familiar with this one: "GIGO".