by Pat Kambesis » Jul 17, 2008 12:12 pm
If I'm on a 3-person team that is experienced and efficient (where I don't have to tell them what to do, they know how to run an efficient survey line and they don't make me wait while they are marking stations), I can get between 200-250 feet/hour - sometimes more depending on nature of passage. Thats doing plan, profile and cross sections, hand-plotting to scale with good detail, with backsites, shot-length average 50 feet. If I have to divert my attention from the sketch then the average drops - how much of a drop depends on how much I have to interact with the survey team (for anything other than confirming data and requesting a few splays). If I split up the sketching duties (have someone else do cross sections and sometimes profiles) then that average goes up even more. On a recent survey trip, we were mapping a kilometer a day in very big passage - and were able to pull that off because we split up sketching duties.
I don't consider myself to be a speed-sketcher, but I do work very hard on being as efficient as possible and thats is really the key. For me, efficiency means:
total concentration on the sketch i.e. can't talk while I'm sketching
having the book set up such that I don't have to constantly be flipping through pages (rubber bands on both sides of notebook to keep active pages handy)
keeping the protractor attached to the book so its always handy and never gets lost or misplaced
having handy several good mechanical pencils with big, effective erasers (cheap pencils have cheap erasers)
knowing map symbols by heart
always putting north arrow and scale on each sketch page so there is never any confusion
working only one station at a time
being familiar enough with the proctrator that plotting the survey line is second nature
receiving the data in the same order for every shot and repeating data back to make sure I heard correctly,
insisting that the survey team identify each number they give to me i.e. distance, front site azimuth etc. This assure that I am recording data correctly - its much more efficient to plot it right the first time, than having to erase and replot.
getting passage dimensions immediately after the distance reading (so I can start drawing walls immediately)
limiting shot length to 50 feet or less (though I do make exceptions). For longer shots, I might like the tape left on the floor so I don't have to guess where I'm at on survey line
I like to have along 8.5 x 11 rite-in-rain paper - for big passages or rooms, or very mazy sections of cave, its easier and faster to work on one page than to have to flip back and forth between several pages. If I don't have big paper, I may duct tape several sheets to make one big sheet. If I KNOW I'll be in this type of passage I'll also use a clipboard (with protractor attached, pencil pocket taped on back) with the big paper.
The efficiency of the rest of the survey team is also important - that means that they work such that the sketcher is NEVER waiting on data from them.
Each of the above saves a few seconds here and there during the survey - and those seconds add up quickly and translate into lots of survey footage.
I think the "original" question was aimed at trying to figure out how long it would take to map a cave - and the answer totally depends on experience level of the survey teams.
pk