Mobility and Economic Feasibility of the Greenland Inland Traverse (GrIT)

Abstract : The mobility and economic feasibility of resupplying Summit Camp on the Greenland ice cap from Thule AFB via a 1410-mile (round trip) overland traverse was examined following safe and successful implementation of the Greenland Inland Traverse (GrIT) proof-of-concept in 2008. The mobility and economic assessments focused on delivery capabilities for a tractor fleet consisting of two prime movers and one fleet-support vehicle and its economics compared with re-supply by LC130 aircraft. The mobility feasibility was based on tractor drawbar and sled resistance measurements collected during the GrIT08 proof-of-concept. Sled resistance measurements indicate GrIT will recover its capital investment and operating costs with a mobility performance of eight 3000-gal. fuel bladders towed per prime mover given a 20% increase in LC130 hourly costs. This mobility level is likely, provided GrIT systematically improves bladder-sled performance (currently six bladders per prime mover) through incremental improvements like the use of black fuel bladders and black HMW-PE sleds. As argued in our previous work, an overland traverse represents an economic buffer against unconstrained and likely LC130 SAAM hourly rate increases. It is recommended that GrIT acquire two prime movers with 36-in. wide tracks (70,000 lb each with a drawbar pull of 21,000 lb) and a lighter weight fleet-support vehicle with 4100 lb of drawbar pull. Loads should be shuttled up the 60-mile transition onto the main ice sheet to eliminate frustrating and time-consuming immobilizations caused by weak snow and steep grades. Additional improvements, such as the development of a lightweight cargo sled, a snow-properties database, and fleet performance analysis tools should be developed in partnership with the South Pole Traverse (SPoT).