How do you guys dig a perfectly straight trench? I use a compass and use the site plan as a map. I take a quick bearing (a tree or rock etc.) and mark the end of the trench (or that leg of it) with paint. I use the inside of the left track as a sight. I line it up with where the trench starts and where it's going, spin it back so that I'm looking at the starting point, and dig. The compass is a big joke at work but I don't care. It has a few different scales and is accurate for making angles in a trench (11.25, 22.5, 45 etc.) This is all important when you're laying ductile.
We just use the surveyors stakes and offsets.:beatsme
compass? i've been doing this for 40 yrs...that's a new one on me, like to hear more about it, if it's that critical, why don't you laser everything in? or..........like CM said....use offsets and elevation hubs?
Same here sewer & storm - surveyors stakes, string line, plumb bob, and a pipe laser Water - surveyors stakes and a string line Dry utilities - who cares as long as its in the easment, i'll throw up a string line if i feel i need to. Pretty simple. I work in a lot of rock so a string line and paint really helps. Its easy to get knocked off course when you are pulling rocks the size of cars out of your trench, or it was blasted so hard that your trench sides go back at about a 3:1
when im diggin sanitary, i usally watch either the beam or ill just watch the bell of the pipe in relaitonship to the top of the trench box in which way im going, for long runs ill ahve the foreman put out a story pole about 15ft in the air so i have soemthing to line myself up for long distances, but "DIP" ill put a center mark out for about 50ft or so pulling off of the offsets, and then watch the sides of the ditch if its a stragiht run , in nice material, it seems to work for me, everbody has there prefernces.:usa jordan
Was I posta dig in a straight line or something Now ya tell me Thanks alot..
That is sum serious trench. I don't think the plywood on top of trench box is quite OSHA approved.
It's not plywood. Thats steel plate.
He's using steel plate. We normally stack boxes but we have used plates in that manner before also.
woops - posted at same time
We have always pulled stringline from CL hub to CL hub and then shoveled sand or rock over the stringline to mark the trench centerline on top of the ground.
I did a water line last winter. About a third of a mile of 12" with no survey. I had catch basins, sewer manholes and lot corners to go off but no curb lines or anything. I got all the valve boxes and fire plugs perfect except one which needed a riser (they changed the road grade twice. Nobody knows whose fault). Just plans, a 200' tape and a compass. For sewer and storm, I use a pipe laser.
Don't do a lot of long trenching these days.. But I used to be in the habit of offsetting the stringline the distance from the centre of the trench (centre of the stick) to my left track and running the paint along the line...than just keep the outside edge of the track touching the paint. If I was only putting the spoil to the right then I'd just run the stringy. I must be getting old, cranky, plain hard to get along with or all of these things because I would do diddly squat these days without a bunch of survey pegs and offsets. Some clients complain and I've even lost jobs because of it but if I can't do it with a stringline and a laser then its surveyor time......they get paid for putting pegs....I get paid for diggin and building.
I'm taking a surveying class at school right now. I'm sure we'll discuss this topic a little, we will actually get into estimating excavation quantities later in the quarter, so I'm sure my teacher will get a little into proper alignment of storm and utility trenches. I've always used offsets to go by, or I'll run some paint. I did about 400 feet 2.5 months ago using only a dash paint line every 6 or 7 feet and I came out pretty darn straight, I felt good about that.
Grab a line marker (like what the use on grass fields with the lime for football and whatnot) and make the mark with that. It stays a lot better than paint, is cheaper, and works even when it is nasty dusty out.
Sharp looking 235. how deep were you guys there?
If you have the room you can always line inbetween your tracks up with where you want your trench. And then just walk the excavator over it the distance you need to go. And then just digout between your tracks. I've did this with the first few foundations i dug with an excavator/backhoe loader. Works for me. Comments?
Hub line with offsets works..