Just a few pics from two of the mapping projects I just completed. The first few are from around the Hunker, PA area.
In pieces.
Out on the rail.
These are a few from around the Finleyville/Venetia, PA area.
Nothing but open skies and miles of track ahead.
The results of a few hours of walking.
Are you doing a continuous topo, or stopping for shots? And how do you handle shots in superelevations?
Continuous for most of it. The Google image only shows some of the shots. I measured the rail at an approximate 2' interval for almost 2.5 miles. I only did this to show our engineer that a 2' interval is a bit ridiculous, but I doubt he got that. I stop and take shots for the bridges, and take the GPS unit off the trolley for things like culverts and utility crossings. The trolley measures the super elevation, and I can export both rails and the centerline points for each shot taken with the trolley.
This is a screen shot of part of the data that is output from the software.
azweig,
I have not used the Trimble trolly.
I gather,that with one shot,you get the other rail and the centerline of the tracks?
Is this correct?
Thanks
Iceman
Yes, that is correct, and the super elevation and gauge.
If my team wins the DC Streetcar design/build contract later this year, the Swiss version is on my shopping list
You could save a lot of rail and ties and everything else if you would simply build the dang thing straight like we do out here.:-P
Have you done any checks with levels to see how the GPS #s are compared to leveled #s?
Who all is on your team?
Not yet. This is mostly for some preliminary mapping to identify some trouble spots. For areas that will be reconstructed/repaired, I'll go back through using the trolley and the S6.
Roadie
email sent
Cool, it would be interesting to find out how that goes, I've tested 4-wheeler topo's against our robot and it's remarkable just how close it is, but not rail location close. With the way yours is fixed to the machine, the smooth ride and the steady HI you have, you may well get within +-.05'.
2' intervals ...I LOVE it. He probably meant 2 tenth intervals.
Depending on the speed of the trolly he could have meant 2 minute intervals?
It was 2 foot. The engineer wanted 1 foot :-/
I would have tied it to the receiver on my truck and drove those 2.5 miles. Hell, you could get over 50 miles in one day.:-D
Trés chic! Sexy cool. Walking?
So...What was the final increment that was settled upon? I personally think anything under 50' is overkill considering vertical accuracy of GPS and the rate of change of slope for a railroad when you're looking at the big picture. But that's my opinion and everybody has one. BTW, that's a great gig you've got goin' on. Better marry that job.
2 foot +/- was the interval I used. Which produced 7,162 locations in approximately 14,380 feet. But if you wanted both rails and centerline, it's 21,486 locations. A lot of what we are using the trolley for is for alignment and gauge issues. Most of the rail we are dealing with is old and has not been lined or surfaced in a very long time. So there are areas that have bows, dog legs, kinks, etc... a 50 foot interval may be too much for certain areas, but a 2 foot interval is over kill in most areas.
Very cool.
