I agree with David Karoly's post, along with all the above. I did my firs digital field trig solutions in the 70's as a young surveyor, using the HP25. suvreyors often plotted coordinates on a worksheet and there were numerous chances for transpositional errors, from the field book to the worksheet to the mylar/or cepia. Very common were switching E with W on final drafted bearings.
Generally speaking, when there was an error, it could be traced to the erroneous numbers on the plat. THE PLAT IS WRONG and is why pincushions are also WRONG.
In the field, it was very common for the crews to find two "good" monuments and hold them as the basis of bearings. Therefore, there is usually one strong line on the ground, and sideshots or side traverses to other corners which increased the odds for error. Throughout this process, if you were using an HP25, you were always keying in numbers,to derive the inverse, or to point stake, and many errors occurred during this process, making the resulting plat wrong.
I had an all weather trig fan that had functions values of every second to 7 decimal places and a green hard covered book full of most every equation and table known to man.
The equations I used most were found on the inside covers of the loose leaf ringed field notebooks.
That information disappeared and was replaced by blank fabric in the 80s.
Did not see a portable calculator until 1974 and it had four basic functions, period.
Many yellow legal sized pads and many loose leaf field note pages were filled with pencil lead in those days.
There was an old road that this was probably traversed down; so the traverse would have been written down in a field book and the sideshot angles to the fence taped out, and since it was a crude fence in trees, a field adjusted distance was OK to probably a tenth or two.
Then the angles were calculated (I'd have plotted them out on a drawing board for clarity), and the paper could also had the summarized calcs on it.
The last calc was the offset line description between courses. The tough part would have been where the road was intended to be 66' from the opposite line. That would have involved bisecting angle calcs, and they were poorly done (so easy on early programs like Survey3 and now on CAD).
Does that sound right?
In my area, they mostly surveyed the actual boundary lines along the boundary lines, or they worked on offsets if needed.
wfwenzel, post: 425309, member: 7180 wrote: This is 1970, no digital calculators yet, they came out in 1972 or so.
I already found out why the angles only went to integer minutes; the tables only went that far, and to enter into the "seconds" world involved interpolation, another undesirable calculation. Not to mention that many instruments least read probably didn't go past a minute?
This was from 1970 and was along a twisting road up a steep grade, and they likely shot an old fence somehow and calc'ed it later. It was never monumented on the east side of the road, just the west side. and the lines were meant to be parallel for some way, but not the entire way.
So, how did they shoot the fence and translate the field notes into a description?
I am familiar with sine and cosine tables, having worked with them since grade school. But not sure how the field to office practices were done.
The Olivetti 101 came out in 1968-9 it had magnetic cards for each function, but it beat the heck out of trig tables and DMD sheets.
I used an Olivetti P-601 with the magnetic cards you had to run both ways thru to do one specific calculation.
Then we wrote the coods to six places in ink on the Mylar this was in 1977
Almost all topo of streets was a chain laid out on the ground with Hand 90s (Arkansas 90s as I learned moving to Houston) and then we swung the rag tape over the chain for the shortest distance
mlove5648, post: 425355, member: 5459 wrote: I used an Olivetti P-601 with the magnetic cards you had to run both ways thru to do one specific calculation.
Then we wrote the coods to six places in ink on the Mylar this was in 1977
Sorry it was an Olivetti P-602, I am getting old!!
My first job was as a rear chainman with a medium size land surveyor in 1971. My chief did all his calcs in the car by hand with a Illinois Tool trig function book. It was a slim pocket volume with the usual sin, cos & tan functions, but also had secant and cosecant as well to avoid division. Anyone remember those? First battery calculator I had was a Commodore, think it was 1972. Just did mult, div, add & sub, cost $50. A bit pricey for a guy making $100 a week.
I remember TI came out with one shortly after which did square roots, first real calculator, but couldn't afford one. First calculator with trig functions I could afford was the original TI-30, around 1976. LED display with a 9V battery. Changed my working life, could comp a highway job with my chief, wasn't long before I made chief. First programmable calculator I owned was the TI-66, was great fun learning to program it, but that was in the early '80s. College courses I took in the '70s required Peters 8-place trig tables, and Von Vega logarithm tables. Both thick volumes that were meant for the office, not the field. Thank goodness for the HP 41-CV or I never would have been licensed, but that's another story and decade.
David Livingstone, post: 425340, member: 431 wrote: In my area, they mostly surveyed the actual boundary lines along the boundary lines, or they worked on offsets if needed.
The slopes, fence, and trees are unworkable, they can't be directly occupied.
Offset calcing was the lesser of two evils.
As the other geezers have reported. Tables in books provided the data to calculate all sorts of things. Long hand or with slide rules. The first hand-held calculator I remember seeing was about 1972. Far to expensive for a married college freshman making $1.75 per hour with a wife making $0.65 per hour at the local T G & Y store. Remember renting one from a business supply store for something like $10 per day and all it did was add, subtract, multiply, divide, figure a square root and store one number. Used it one day for a particularly challenging semester final in one of my engineering classes.
