|January 25-27, 2007
The advance DEPTHX team arrived at Rancho La Azufrosa last night after an eventful set of days crossing the border. It is difficult to explain all of the details from our plight, but let me just say that it deserves a write-up ofsome sort.
We left Stone Aerospace in Del Valle, Texas Thursday afternoon, arriving at our hotel in Harlingen after midnight. Awaking the next morning, we crossed the Rio Bravo at the Los Indios crossing, one that I always try to cross since it is out of any urban area. The customs agents were very nice there, but since it is a satellite office, they said we needed to cross in Matamoros. We stayed at Los Indios for about 5 hours calling back and forth to the U.S. Embassy in Mexico City, trying to convince the Mexican officials to let us pass (we even set up our mobile satellite internet at the customs area!), but finally about 12:30 it was determined that we must turn around and go to Matamoros. One hitch.....we had to now go back through U.S customs towing a trailer with a submersible robot on it!
We spent 2.5 hours going through the commercial import line (with all the big trucks), and were lined up for a full-vehicle x-ray scan. After some convincing that this could fry all the electronics and ruin the project, the U.S. customs agents agreed to just manually scan to see if we had any radioactive material. Since we didn't, they let us pass back into the U.S. Back where we started from in the morning, we regrouped in the parking lot of the hotel, printing out equipment invoices emailed from the U.S. Embassy, drafting a manifest list, and re-wrapping the bot frame in a tarp. By 4:00 PM we were on the road to Brownsville, destination Matamoros.
While approaching the bridge, we were met by a swarm of U.S. customs and "ICE" (I think it stands for International Commerce Enforcement) agents. Apparently, there are export restrictions on some stuff, and they were quite confused as to how to handle our interesting caravan. After sitting parked, poised to cross into Mexico, our "friendly" U.S. customs agents (in the sake of National Security, I'm sure) decided it was necessary to "detain the commodity" until they could run this up the chain of infinite bureaucracy. This meant it was locked up in holding yard Friday night. We had no idea how long this would take, and holed up in a nearby Best Western pondering our fate.
Saturday morning....Our options limited, I began to receive phone calls from the customs agent working our case. I have to say this guy was great. He went the extra mile to get us going again. After contacting our science liaison at the U.S. Embassy in Mexico City, he decided that it would be OK to let us go with "the commodity" and continue onto Mexico. We hooked back onto the trailer and crossed the Rio Bravo for the second time around noon on Saturday. I never felt so relieved to be in the hands of Mexican bureaucracy instead of the U.S.
Crossing through Mexican customs was very straight forward. A couple of hours getting forms filled out and documents stamped and we were heading south through the streets of Matamoros by 3:00 PM. The rest of the drive was quite uneventful, except for the fact that I was pulling a 8-foot wide trailer on roads that were 8 feet, 2 inches in each lane with radical drop-offs on the shoulders. I can attest to the "white-nuckle syndrome."
We finally arrived at Azufrosa around 8:30, and began the ominous task of unpacking. The internet seems to be working well, although not at light speed. It's better than nothing at all. I'm sitting in the palapa drinking coffee writing this email, it's pretty cool.
Ph. D. candidate
Jackson School of Geosciences
The University of Texas at Austin
January 28, 2007
Having successfully arrived intact at Rancho la Azufrosa (site of Cenote Zacaton) and greeting ranch owner Alejandro Davila, we began setting up basecamp in ernest today for Zacaton Mission 1. This was very much a “MacGyver” day, with Marcus Gary showing an extraordinary collection of eclectic skills (welding, burning, electrical contracting) that go well beyond the experience of the average hydrogeology PhD student.
Marcus, who is in charge of site logistics in addition to managing the environmental sensor array for DEPTHX, arranged for the transport of a 12 m seagoing shipping container to the ranch to serve as the field lab. First order of business, however, was the construction of a “bot garage” for DEPTHX to protect it and the tech crew during assembly -- the bot was transported to the site in pieces to avoid shock loading of sensitive electronics.
The day was mainly spent welding framing poles in place for the garage, stretching aircraft cable for tarp suspension, and running electrical lines into the shipping container for the lab benches. By nightfall we had fluorescent lighting inboard and bench power. Tomorrow begins the formal process of painstakingly re-assembling the bot.
January 29, 2007
Marcus and Robin Gary left for Austin today - Robin returning to her job at USGS and Marcus to fetch an additional load of supplies for basecamp. This left us with a skeleton crew of John Kerr and myself to work the finer issues of setting up the field lab and re-assembling the bot until further reinforcements arrive.
First order of business was to uncrate the bot. At 1.5 metric tons DEPTHX is an industrial strength machine (rated to 1,000 m ocean depth), but this also means it’s not something you toss about by hand. Alejandro Davila, the owner of Rancho la Azufrosa, kindly made arrangements with a local Tampico-based crane company to ship a mobile handler to the site. We then began unloading all the electronics modules into the field lab for individual checkout.
Above: about half of the pressure vessels that go inside DEPTHX, at the field lab.
Although it seems like a simple process, DEPTHX has over 500 electrical connections, all of which run through scores of dis-connectable pressure rated cables... and each of those, along with the housing closures, have hundreds of orings, which are lubricated and therefore attract dust... of which there is plenty at Rancho la Azufrosa. So every make-and-break of a cable connection or housing lid means replacing orings, re-lubing, and sealing before any contamination can enter.
Today we managed to load the variable buoyancy engine (VBE) ballast as well as the two pressure housings for the redundant lithium-ion power supplies into the bot frame. We also charged up the VBE pressure drive tanks (5,000 psi carbon-epoxy construction) and mounted those.
The weather has been cooperative, partially sunny, a bit windy, and 70F. The only point of serious concern today was that while totally focused on our work we began hearing strange “clacking” noises outside the lab trailer and emerged to find a large herd of goats inspecting the bot at close range... in fact they had it surrounded and were licking the sonar transducers. Fortuitously we caught them before they got the idea to chew on the cables. New line item on the pre-flight checklist: remove goats from bot vicinity.
|John Kerr attaches the Variable Buoyancy Engine (VBS) ballast tank to the top of the bot - the VBS has a differential displacement of 26 kg to compensate for compression-induced buoyancy loss as the vehicle descends.
||Mounting the pressure housings for the twin Li-Ion power supplies that drive DEPTHX. The yellow cylinders are 5,000 psi carbon-epoxy pressure vessels that are used to drive the VBS. The gray cylinder at top center is one of two vertical ducted thrusters that work in concert with the VBS to vertically stabilize the bot and allow it to hover.