[Bill Schwab]

Paul:

I'm throwing this one your way because of your vast experience with these toys, so, here goes. Lately, business is taking on a new nitche market. We have been getting lots of calls for long and high SRW's, and grading to boot with them. Many properties have a 3 or 4-1 slope in the back, and we are getting requests to remamage the soil that is there by creating terracing and cutting to 2-1 drops to each terrace. I am studying for a class A general engineering license, so in our state we can exclusivley do this type of work without any landscape involved. I am looking at a Cat 267 or 277, which, is the perfect size machine for the work requests.

Slope lazers. Can you project how much time they can save me, and even if this is the exact weapon I should be using foir this type of job, and, particulalrly, how soon could I assuming I got good with one, would I recover my costs over using a transit and simple string line?

[PSUscaper]

I've always thought of slope lasers as being more practical for large, open spaces, such as sports fields, which is where I always thought paul used them.

On a retaining wall site, it seems like the slope laser would have to be moved and relocated many, many times to accomplish what you want, and the distances would not be necessarily long enough to make the time saving of conventional methods add up. The more set-ups, the less time saving it becomes.

I'd also be somewhat leary of a rubber tracked loader vs. a regular old steel tracked dozer for this kind of work. A larger tracked excavator may be more suitable for this sort of job.

I've always thought the real value was obtained on large open sites or long runs that required exact accuracy, such as sports fields, parking lots, long drives/roads where small drops or rises would cause serious problems, such as ponding. The accuracy a slope laser would give you for a 3:1 or 2:1 slope would seem somewhat overkill on most projects.

[Paul]

Slope lasers have there place, but I'm not sure your sites are big enough to justify the expense. I'm qualifying that because of my usage has been with standard dual slope lasers on large job sites. My newest dual slope laser limits out at 45% and 25%. Now thats pretty steep but it might not be seep enough for your work. I would have to know how big your projects are area wise.

What I'm tiring to understand what you need to slope? SWR walls need a standard laser, large paving jobs and critical grading for drainage can benefit from a slope laser.

We purchased our lasers for sports fields and discovered that large paving jobs can be graded out faster with it. To grade behind a wall might be critical but the equipment that they have for that type of machine grading might not be what you want to do that close to the wall.

Think of a slope laser as a no sag string line that you can't trip over.

The laser it's self is not that bad as far a purchase price. Something in the $5,000 to $7,000 range, then adding on the attachment and receiver you can add another $10,000 to $17,000. Cost recovery on a standard sports field (soccer field size) is in the order of 75 hours less machine grading time. Now figuring this at our standard equipment operators wages of $53 per hr. That one field would see a payback of the total equipment price of 20%-25%.

[Paul]

Penn, the nice thing about slope lasers is the ease of adjustments, I can walk up to one that I have and without moving it change it from .25% to 45% with the push of a button. So most times it stays in one place. The newest ones have a transmitter in the cab of the equipment and they talk to one another, so you can change things from the cab. But your right about questioning the usages of a slope laser for his type of work.

[PSUscaper]

I was just thinking about the general layout of a SRW site........

For a practical slope laser setup, you would have to have all the walls running perfectly parallel to each other, on a slope with no obstacles (ie, trees, buidings, etc) and be able to set up at the top of the slope.

The problem is, the walls will probably be runing around curves, making it nearly impossible for a single setup, and require many movements and recalculations. The walls may also step down, and many different' slopes may need to be determined as they may vary from 3:1 to 2:1 to maybe 3:1 again.... Also, being that the final grade may not be set until the final wall is built, the slope laser would only be able to set up after each wall of the terrace is built, as the top of the whole thing may be 'air' until you build up to it.

Sorry if I lose everyone, but my past surverying experience marking out construction sites taught me very well what you can and can't do, or more importantly, how much of a pain in the butt it can be trying too.

I use to always love marking out road radius's on steep downhill slopes......that was always fun!

[Bill Schwab]

Paul:

Average lot size here is going to measure between 85 feet wide up to 130 feet wide,, and rake out another 85 to 130 feet with a 3 or 4-1 slope all the way down to bottom. Typically, we would take the grade as it is, build the sides up 8" or so to create a swail for drainage (we cannot discharge ANY water from one property onto the next in this state) gouge out some soil to create a 15' wide terrace with a 2% slope, then drop from that elevation with a 2-1 slope, onto another 2% slope, until we get into the area immediatley behind the wall where the geo grid is going to compacted into. After the top side is cut/filled compacted, we would then gouge out 10-20 feet into the hill, for the grid and wall, exporting as little soil as possible.

What we have just done is allowed a homeowner to use two terraces that with the existing 3-1 slope, would just be unusable space. Since properties are so expensive in this part of the world, allowing more usable area would add space to a yard without adding a great deal of cost in comparison to house additions. What we have been doing is just using a standard lazer and a transit, after we take a benchmark somewhere. This way definitely ties up two men. I'm just looking for a way to turn better numbers.

Penn:

We had a D-3, 6 way machine, and a 935 with a 4 in one bucket. the reason for the rubber track is simple. Access. The two machines mentioned were about 6-12" wider than 99% of all properties we work on will allow. We may even go down to a 247, it depends on what will work most of the time. Steel tracks also presented issues with driving over drives and easements where rubber would just make marks. I agree with you however, in steel is the way to go if you can get them back to where you are working.

[Paul]

Bill in that small of space, I don't think that a slope laser with one of the grading attachments that I have used would work, I might be wrong, a demo from your Cat dealer long with a couple of phone calls to a laser sales man might help you decide. Talk to them separately!

A dual slope would be able to make those drainage cuts and 2% slopes work without having to re-shoot, what worries me is the tight confines of space your working with. 15' by 80' is not a lot of room for the machine to really work end to end. But I really don't see a big time savings

[Bill Schwab]

I just had a thought mnonent here...Maybe this is nothing, maybe it is... Lets say a person made a set of light weight aluminum extrusions that you could stake on the lot lines and held a set of briging that would hold a lazer. The lazer would sit in an extendible boom similar to what a tripod uses for a camera. All radio controlled as the machine needed to pass under it. When you hit resume, it would drop back to the same setting as before to hold a line....I'm wondering if this could be a man hour saver.