Leg 209 began at 0956 hr on 6 May 2003 as the first line ashore at Berth 3, Porto Praça Maua, Rio de Janeiro, Brazil, ended Leg 208. Pacing items for the port call included resupply of fuel and drill mud bulk, loading casing scheduled for deployment during Leg 210, and installation of a remote diagnostic system for the active heave compensation (AHC) system. A complete overhaul and test of the drawworks transmission was also completed during the port call.
Two power outages, traced to a faulty transformer, occurred on the JOIDES Resolution early on the morning of 10 May. Repairing the transformer ultimately became the primary port call pacing item and resulted in a 1-day delay in our scheduled departure. After rotating the ship 180° to load a new spool of drilling cable on the starboard side, mooring lines were released and the last line was brought aboard at 0912 hr on 12 May. The pilot departed at 0954 hr and the vessel got under way at full speed for the 2627-nmi transit to our first site.
Transit speed over our first 4 days at sea averaged 11.3 nmi/hr. During the transit, an air sampling system for airborne microbial study was modified and mounted at the water table level of the derrick.
At 0925 hr on 15 May, the ship's master was informed that the Overseas Drilling Ltd. Electrical Supervisor required medical evacuation. At 0946 hr we changed course to 328° and steamed toward the port of Aracaju, Brazil, 109 nmi away. At 1654 hr we arrived at our rendezvous location (11°18´S latitude, 36°45´W longitude) and proceeded at reduced speed until arrival of a medivac helicopter. Brazilian police helicopter PT-HVA was on board by 1726 hr and departed at 1731 hr. We immediately resumed full speed, changed course to 055°, and proceeded up the eastern coast of Brazil. Overall impact to the leg for the medivac operation was an additional ~60 nmi steaming, or ~5 hr.
During the next 6 days of our transit we averaged 11.7 nmi/hr, until a wind heading change and the Equatorial Countercurrent slowed our speed. We arrived on Site 1268 at 0500 hr the morning of 22 May. Our transit totaled 2680 nmi at an average speed of 11.4 nmi/hr.
The planned location of Site 1268 was revised during transit from Rio de Janeiro after detailed review of the video tapes from the 1998 Shinkai 6500 Dive 427 (Fig. F1). Site 1268 was to be drilled in thin sediments at ~3011 meters below sea level (mbsl), overlying a flat, planar outcrop of serpentinized peridotite (probably a fault surface) visible a few meters downslope. Upon arrival at the planned location, the precision depth recorder (PDR) in the underway geophysics laboratory indicated a depth of ~2896 meters below rig floor (mbrf) (2885 mbsl), quite different from the expected depth. Given that submersible dive navigation can be uncertain, we undertook a PDR survey of the seafloor to the southeast (downslope). While making up the drilling assembly, the rig crew discovered a significant crack in the stress relief groove of the pin thread at the first 81/4-in drill collar. This collar was laid aside and we decided to magnaflux inspect the remaining eight drill collars in the bottom-hole assembly. No other cracks were found during the inspection.
While running the drill pipe, we chose a position ~600 m southeast of the originally planned location, with a PDR depth of ~3040 mbsl, to start a camera survey (Fig. F1). However, when the camera depth was at ~3080 m, the sonar on the camera sled still could not detect bottom within 100 m. At this point, the ship began moving slowly northwest toward the originally planned site location. Bottom was first detected at ~3180 mbsl at a position ~500 m southeast of the originally planned location. Bathymetry determined during the camera survey conformed closely to bathymetry based on Shinkai 6500 Dive 427 at the same latitude and longitude, so we decided that the PDR depths were probably incorrect. At this point, the drill string and camera sled were raised to a bit depth of ~3008 m, and the originally planned location for Site 1268 was slowly approached. Again, bathymetry determined from the camera survey at the originally planned location conformed closely to that observed during Shinkai 6500 Dive 427 (Fig. F2), confirming the theory that dive navigation in this case was accurate and PDR depths were incorrect. The close equivalence between camera survey and dive bathymetry indicated that we were very near the originally planned location. Push tests indicated that sediment thickness was ~4 m, slightly thicker than anticipated but within acceptable limits. The positioning beacon was released from the vibration-isolated television (VIT) frame ~20 m away from the identified spud location prior to recovering the VIT frame.
Before initiating coring we deployed the Water Sampling Temperature Probe (WSTP) to obtain a temperature and a seawater sample for a microbiology contamination baseline analysis. Hole 1268A was spudded at 0620 hr on 23 May. After cutting Core 1R, AHC was discontinued due to erratic performance. AHC performance data and coring parameters were recorded in the newly installed Maritime Hydraulics diagnostic computer and the Texas A&M University TruVu rig instrumentation system. TruVu was running in the 1-s capture mode. Marine Hydraulics–Norway remotely accessed their diagnostic computer and downloaded the data for analysis. Initial reports indicated a possible problem with the AHC motion reference unit.
Core 1R advanced to 14.0 meters below seafloor (mbsf) (Table T1), allowing the bit to stay in the hole during the next connection. A standard rotary core barrel was used without a core liner. All subsequent cores were taken using nonmagnetic chrome-plated inner diameter core barrels. In order to improve recovery, we opted to retrieve cores nominally every 5 m (half-cores).
Sepiolite mud sweeps (10 bbl) were circulated every 10 m, and the hole remained stable through Core 28R (145.1 mbsf) (Table T1) with no fill or overpull during connections. After making a connection before cutting Core 29R, the driller noted elevated torque and ~1.0 m of fill in the bottom of the hole. All drilling parameters returned to normal after pumping a pair of 20-bbl sepiolite mud sweeps. While cutting Core 29R, drilling parameters indicated the hole had collapsed, stalling the top drive and preventing any further rotation or axial movement of the drill string. After an unsuccessful attempt to free the pipe, we decided to sever the drill string above the bottom-hole assembly. The mate to the severed pipe joint cleared the rig floor at 1930 hr, ending Hole 1268A and drilling operations at Site 1268. The average penetration rate for the hole was 3.9 m/hr.
1 Examples of how to reference the whole or part of this volume can be found under "Citations" in the preliminary pages of the volume.
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