GrIT: On to Summit

May 18, 2010
 All photos: Robin Davies

The GrIT team greets Zoe Courville at NEEM.

After about three weeks and 400 miles—many of which were wind-blown and snowy on the soft, roadless route toward Summit—the Greenland Inland Traverse team (GrIT) rolled into the international deep drilling camp NEEM last Thursday, 12 May. 

GoNorth! Too  

The Polar Husky superstars of GoNorth! arrived on the 12th as well, in time for project members with teaching and other commitments to meet the flight scheduled for the 13th. Of course that flight was delayed a day due to weather on the ice cap, but eventually the plane came, and personnel were appropriately shuffled.  

The GoNorth! Polar Husky super stars run into NEEM camp.

Exit Jim Lever, Enter Zoe Courville

The GrIT team welcomed Zoe Courville of CRREL on Saturday. We hear the mood was festive at NEEM camp that evening, as many camp personnel were newly arrived on the day’s ANG flight, as well.  The NEEM blog site notes that “Everybody had a fine evening, and a lot of people joined in the mid-night dance, featuring the Danish group “Sweet hearts.” 

Back to work on Sunday: The GrIT team conducted maintenance on traverse vehicles, delivered 1500 gallons of fuel to NEEM, and reconfigured the loads, shifting another1500 gallons of fuel to the Tucker’s fuel bladder. Net load reduction for the Case: 21,600 pounds. “The Durabase (a semi-flexible plastic bed) is now on High-Molecular-Weight sleds to see if the sleds reduce the drag,” project manager Allen Cornelison noted. 

The team headed out for Summit on Sunday, another ~430 miles ahead.  On Monday “the Case was able to grab 7th gear,” a first, wrote Cornelison.  Still, “it was unable to go any faster probably because it was making 14-inch ruts.”  Despite soft snow conditions, the team advanced 45 miles.  

The LC-130 airplane (right) blows off the runway at NEEM. Skiway conditions were soft due to warm temperatures and wind storms. The "Iconic NEEM Dome" (the camp's main building) is seen just left of center.

More Sled Mobility Tests

The qualities of Greenland’s snow surface and sled mobility are clear foci of the GrIT’s experimental component. Before departing on the traverse, CRREL personnel at Thule fitted the Durabase sled with sensors that collected data at the snow/sled interface; when he returns to CRREL, Lever will analyze these data in hopes they shed light on how to make the interface more slippery. 

Back at Thule earlier this spring, Jim Lever prepared the HMV sleds for mobility experiments. Here, the sled is outfitted with heaters. The sensors to collect data on temperature and mobility can be seen along the edges. A second sled was tested using enhanced passive (solar) warming methods.

Jim Lever (right) changes batteries powering a datalogger collecting information on the mobility of the HMV sled with passive warming. The brown fuel bladder is covered with a radiation-absorbing black material. In the background, the second HMV carries a fuel bladder without the black material, for comparison. Allan Delaney (left) and 'Swing Boss' observe.

In addition, after departing the GrIT, Lever flew to Summit Station, where he is conducting mobility tests on a raft purchased specifically for traverse development.  Jim’s findings may be applied to improving bipolar mobility—for GrIT and its southern cousin, “SPoT” (the South Pole Traverse). 

The Greenland Inland Traverse is funded by the National Science Foundation (NSF). CH2M HILL Polar Services and Cold Regions Research and Engineering Laboratories are working together with the NSF to develop the traverse infrastructure and route. The 2010 spring traverse has several foci: find a safe overland route to Summit Station to help reduce logistical costs and environmental impacts of conducting research there; provide a research platform for scientists conducting field work in Greenland; optimize mobility by focusing on the sled/snow interface.  For more field notes coverage of GrIT, click here 

GrIT contact:
Allen Cornelison, Polar Field Services, CH2M HILL Polar Services
GrIT project manager

GrIT Details: Sled Mobility Tests

April 5, 2010

Meanwhile, Back at the Transition . . .   

Unloading the first of two 60-ft sleds to be used for mobility tests. Looking south to the icecap, the pointed hill on the skyline is the ramp. Photo: Robin Davies

Unloading the first of two 60-ft sleds. Looking south to the icecap, the pointed hill on the skyline is the ramp. Photo: Robin Davies

While the SCAT (Strategic Crevasse Avoidance Team) chugs slowly across the first leg of the traverse route to Summit looking for hidden hazards, back at Thule Air Base, a set of experiments will soon begin. The goal: to discover how to maximize operational efficiency at the sled level.  CRREL’s Jim Lever, who is running the technical side of this effort, collaborated with PFS’ Allen Cornelison to provide the following background on sled mobility tests, which will begin out at the transition later in the week.  

We want to reduce the over-snow sliding friction of the fuel-bladder sleds to increase the payload GrIT can tow to Summit.  Sled temperature plays a dominant role: the warmer the sled the lower the sliding friction.  Warming the sleds is a challenge at the low temperatures encountered on the Greenland ice sheet, and we will try two approaches.  

1.  One sled will have black covers over the two fuel bladders to absorb the sun’s energy to help warm the fuel and consequently the sled.  The image below shows this sled with the rear 3,000-gallon bladder partially filled.  This passive heating is simple and inexpensive and should work well during the long daylight hours when skies are clear.  

A sled with two fuel bladders covered in back material waits at the transition. The ramp can be seen behind the truck. Photo: Jim Lever

2.  The other sled will have electric heating blankets under its two bladders. The image below shows it being assembled prior to transport to the ice edge. The four blankets are rated at 1,700 watts each and will be connected to a 15,000 watt diesel-powered generator. The generator is over-sized to accommodate reduced power output at high altitude (up to 10,000 ft) expected along the route.

Jim Lever prepares the second prototype sled in the warehouse at Thule. Photo: Allen Cornelison

Each sled contains 46 thermocouples to measure the sled-snow interface temperature along its length (you can see them disappear under the heating blankets in the picture above).  Other sensors will measure towing forces, air and bladder temperatures, solar insolation (how much energy is available from the sun), travel speed and altitude. A datalogger stores all these data until Jim downloads them to his computer for analysis.  

If all goes well, we will learn how to build the next generation of sleds to increase the efficiency and hence payback of GrIT for fuel and cargo delivery to Summit.  

The Greenland Inland Traverse is funded by the National Science Foundation (NSF). CH2M HILL Polar Services and Cold Regions Research and Engineering Laboratories are working together with the NSF to develop the traverse infrastructure and route. The 2010 spring traverse has several foci: find a safe overland route to Summit Station to help reduce logistical costs and environmental impacts of conducting research there; provide a research platform for scientists conducting field work in Greenland; optimize mobility by focusing on the sled/snow interface.  For more field notes coverage of GrIT, click here.  

GrIT contact: 
Jay Burnside, Polar Field Services, CH2M HILL Polar Services 
Construction/Operations manager  
Jay at polarfield.com