Field Notes: The Polar Field Services Newsletter

CPS Convoy Heads for Summit, Greenland

Three GrIT tractors roll across Greenland's icesheet. All photos: Robin Davies

It’s that time again! CH2M HILL Polar Services personnel are enroute to Summit Station on their annual overland resupply traverse. The Greenland Inland Traverse (“GrIT”) team departed the coastal Thule Air Base on the U.S. National Science Foundation-funded GrIT earlier this month.

“The GrIT crew seemed happy, although a bit anxious, to get out of town following the 4th coldest winter snap in Thule history,” wrote CPS project manager, Geoff Phillips. “It was a long, cold prep season for GrIT that wasn’t without its unexpected yet chronic equipment troubles that always concern the crew when they pull away from town. They left at the beginning of the longest stretch of fair weather we have had since we got here in late January and it appears to be following them up the route.

Winds blowing 10-15 knots and temperatures around -45 made early spring work near Thule Air Base a challenge.

“They made great time up to Camp Century (approx. 112 miles out) although they had to fight for every mile they made.  The snow is very soft in some locations and required double and occasionally triple heading the loads (2 or 3 tractors hooked up to one load).  That makes for long, slow days and exhausted crewmembers.  They are staying in good spirits and remaining optimistic that the snow will improve soon.”

You can follow the GrIT via a website that uses GPS positioning information from tiny tracking devices affixed to some of the traverse vehicles. Bookmark the site and check back frequently:

The 733 mile route follows a path established in a 2008 traverse between Thule Air Base and Summit Station, the research station funded by the U.S. NSF in cooperation with the Government of Greenland.  The traverse continues previous efforts to establish a safe and efficient overland route between Thule and Summit Station.  An overland route provides a greener supply delivery option to Greenland stations which currently rely on air freighting.

A ground-penetrating radar affixed to the front of the vehicle found a safe route through the crevasse zone in March.

In March, the Strategic Crevasse Avoidance Team (SCAT) surveyed and flagged a safe route through the crevasse zone, a challenging 70-mile transition between Thule and the ice sheet proper. Using a ground-penetrating radar and antenna attached to a boom affixed to the front end of a tracked vehicle called a Tucker, SCAT images the ice sheet to keep on the lookout for crevasses. When the team suspects a crevasse, they probe and flag its location using Global Positioning Systems Technology. The ice sheet in this area is so active that technicians must study the route each time GrIT crosses it.

Back to the GrIT. The overland convoy is led by the SCAT GPR Tucker, one Case Magnum, and two Case Quadtrac tractors, all towing a multi-sled cargo train that includes about 45,000 gallons of fuel, two 12,000 gallon double-wall fuel storage tanks (for Summit), a “sheep’s-foot” roller packer (for Summit skiway grooming), a Crew Quarter living module along with miscellaneous materials, supplies, and food for the traverse.

The GrIT 2012 crew is Pat Smith (Field Manager/Lead Traverse Mechanic), Robin Davies (Mechanic), Shep Vail (Traverse Equipment Operator) and Galen Dossin (Mountaineer/Field Safety).

“The crews [traverse, SCAT, construction, technical, etc.] spent about eight weeks in Thule building the next version cargo sleds and servicing/repairing all the heavy equipment that is needed on the traverse. They also put all the sled pieces together to form the larger traverse sleds that you see in the pictures,” Phillips says.

Sled redesign is ongoing in hopes of maximizing fuel and time efficiency.

“In 2010 we tried to use air-filled pontoons that were purchased off-the-shelf from Whitewater Raft Manufacturers. They proved the concept that the design will help steady the cargo on top of them and even-out the effects of rough snow-surface conditions. In 2011 we tried a custom pontoon made from similar materials to those rafts, which worked well but had problems holding air over the course of time. This year’s design is similar but made from a different material and installed in a large pouch that will hopefully keep snow out of the pontoon area which caused trouble in the past,” Phillips explains. “The HMW sled looks the same as previous years but has a slightly modified formula for the plastic that was based on CRREL testing and research on the material. The new type of HMW should be more resistant to tearing while maintaining its ‘slippery’ qualities on snow.”

A cargo sled clambers over sastrugi (wind-sculpted waves on the ice sheet).

Another notable change in the GrIT set up is the replacement of the Wannigan, the mobile kitchen and office that was towed (along with the outhouse) behind the tucker.

“The Crew Quarters not only houses the kitchen facilities and communications gear (same as the Wannigan last year) but it also has berthing for five people and a shower/powder room. You know those GrIT guys need a Powder Room! It is a huge step up in comfort compared to the rather small Wannigan and sleeping tents,” Phillips says. “This should help with morale and crew fatigue since they will have a warm kitchen facility and bedroom always available instead of having to build a tent city every night.”

The GrIT crew hopes to arrive at Summit Station late this month, weather willing. On this trip they’ll deliver fuel to NEEM (the North Eemian drilling camp, an international ice-core harvesting camp), pick up cargo from a 2011 deep field glaciology effort by Hans Thybo, and return to Thule in mid to late May. –Marcy Davis

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