Benchmark education and activisim...

[rusty0101]

Visited my dad this weekend, and spent some time out looking for some benchmarks in his area. Of the six I found, and 1 found destroyed, I would say that there are five that could warrent attention.

 

With the first one, ON0782, the mark itself was OK, however one of the reference marks shows serious damage. Too the point of being considered destroyed. As the RM does not have a distinct PID, reporting the damage requires awareness that the damage does not make the TSD unusable. Though it may be considered to be in a risky area.

 

The next two are just off of a runway for a local airstrip. Remember to check the Data Sheet for a contact, follow common sense when working in these areas (Be a hunter, wear blaze orange, and if possible a hard hat. They really are not that hard to find, check Sears, or expensive.) ON1300 & ON1301.

 

My fourth was a church spire that was destroyed two years after the last time the mark had been recovered. I found that it was interesting to find out when and why the church was destroyed. I also had the opportunity to explain why I was recovering benchmarks. In this case the person I was explaining it to was involved in the church that this one was combined with, and when I explained that a surveyor coming into the area, with the out-dated information, may mistakenly try to use the wrong spire to try to verify new work that is being done, she understood immediately that doing so could put the surveyor in entirely the wrong place. ON0788

 

The last mark that I visited is another church spire. This one poses a slightly different problem, in that the church it is part of, is undergoing renovation. Unfortunately one of those renovations is going to re-align the tower. The reason for this is that the foundation sill for the tower is believed to be rotting, and the people working to preserve the church believe that this should be corrected. For surveyors this can pose two different problems. One is that over some period of time the spire has moved from it's original constrution (possibly in 1866 along with the rest of the church) through the benchmark being first observed in 1960, through today. In this case I doubt that movement has been great, possibly a shift of 2-5 inches, however for near observations this may affect the percieved location of work being done under survey. None of the images I have seen give me a good feel for how much the tower/spire has moved, nor when that movement may have begun. ON0942

 

This is another mark that would support further investigation. I did not have the time today to do that, but I do expect to make more trips into the area.

 

-Rusty