For some reason, and probably because I could, laying out project sites became my task. Whether it was setting string line for forms, or plotting topographical information for earthwork, if I didn't know how to accomplish the task, I had to learn.
Old school craftsmen I worked with had a method of squaring by using a 3,4,5 system of measuring. One didn't feel comfortable with anything but doubling the numbers, which I understood, but I think he probably couldn't comprehend any multiple of the numbers would work. Still, his other skills were invaluable with building projects. Simple things, such as always laying out tile, or flooring from the centerline were things I didn't know, but when applied, led to the understanding how the final aesthetics required the method to insure an even border, or correctly centered.
Setting long straight lines presented some problems. Regardless of the distance, if there were two points to work from, a long string line could allow setting intermediate points, but very long distance could be inaccurate due to deflection by the wind. After the company I worked for allowed me to buy a meridian transit, the feature of being able to tilt the telescope allowed me to use a helper, while I sighted their location, and fine tuning the location of a stake, or mark on paving. I didn't trust the feature for turning angles, unless it was only for a ball-park location. I relied on two measuring tapes for that location, and had to watch helpers like a hawk to guarantee they were holding the tape in the right location. I failed to do that one time, several anchor bolts were poured in the wrong place, and the butt-chewing wasn't nearly as tough as my own feeling of disgust.
When after years of using poor-boy methods for layout, the company I worked for finally bought a total station. The flexibility of the instrument was liberating. I could set some fixed points far away from the work, which allowed recreating points inside the project if they were disturbed. The software bought for plotting the points allowed the creation of unknown points, which could be downloaded into the total station for use in the field. Instead of spending a long time using string lines, and measuring tapes for layout, I could establish points with one helper.
When I first started construction, TxDot, which was then called Texas Highway Department, had a survey crew in most every district office. Their job was to establish stakes for the contractors, which could be everything from offset points, to establishing the right of way. They, at that time, used transits, long survey chains, and a lot of walking to complete their task. When they had free time, they worked sections of the highway to check the location, and elevations, of permanent markers established around the district. The long process could mean long journeys on foot to establish temporary bench marks, arriving at the survey marker, and then doing the same back to where they started. The task involved what is called a level-loop. All the grade shots during the traverse were placed in a field book, and when the loop was finished, if a discrepancy was found, the loop might have had to be completed again to determine the cause of the error. Today, such a loop can be performed my one person with GPS or a remote controlled total station.
Over time, TxDot moved away from having a field party, and contractors became responsible. With a large lay-off during the seventies, many members of the field parties were hired by contractors, and stayed, instead of returning when the state wanted to hire them back during better financial times. That led to my opportunity to work with them, learn invaluable skills, and increase my knowledge.
With technology today, the old methods are becoming forgotten. GPS allows accurate measuring without understanding the methodology, and those doing the layout work probably would be lost if they had to accomplish the same task with a transit, a survey chain and a pocket calculator. It's like many things which may never be necessary again, but if they do become necessary, there will be few around to teach the methods.
