OLD POLERemediation Project FY11

Old Pole Location

Objective

• The objective was to ensure that the area surrounding the Old South Pole Station identified as off limits and unsafe, was evaluated and made safe for normal surface travel and work by personnel or equipment.

Background

• During the early FY09 winter, the culvert at the entrance of Old Pole was removed and the opening was filled in.

• Due to an unexpected void beneath the surface, a D7dozer sank approximately 6 feet below the plateau.

Background

• During the FY10 summer season, Old Pole was surveyed using ground penetrating radar (GPR)

• The majority of the structures were approximately 30-40 feet below the surface of the plateau, with one unidentified structure approximately 10’ below the surface

• Due to the depth of the structures, the site was determined to be safe and able to support heavy equipment movement

MT865 Challenger

• Upon completion of the bulk dozer work, a final pass to groom the unfinished surface with a MT865 Challenger was being performed when the tractor dropped into an unexpected void beneath the surface.

• The tractor sank approximately 30 feet below the plateau at its lowest point.

MT865 ChallengerJanuary 2010

D8 Dozer

• During the response to the Challenger incident, a D8 dozer dropped in another hole approximately 150’ grid west of the Challenger location.

• The back end of the D8 dozer sunk approximately 8’ with the front of the dozer level with the plateau.

• The equipment was recovered with no injuries to the Operators and only minor damage to the MT865 Challenger

D8 Dozer

Equipment Recovery

The D8R was successfully retrieved from the site.

The successful retrieval of the Challenger MT865 tractor was completed after excavating a ramp to access the machine.

FY11 Objective

• The FY11 Old Pole Remediation plan was developed and implemented to collapse the Top Hat structures that were built on top of the T-5 building structures.

• Combined effort by Raytheon Polar Services (RPS), National Science Foundation (NSF), Cold Region Research Engineering Laboratory (CRREL), and the McMurdo Explosive Team.

• Test Blast at Old Pole

Top Hats• Top Hat extensions were approximately 8’ in height.• Reduce snow loads to buildings and act as insulation barriers to

prevent snow melting and leakage • In some cases two levels- 16 feet high, leaving a manmade void

above the T-5 buildings.

CRREL/GPR Survey

• Old maps and data found in the archives as well as the 2010 GPR report were used to initially locate and flag the area

• The team fabricated a 15’ boom mounted to the front of the PB100 tracked vehicle

Old Pole GPR Survey

Explosive Team

• One Lead Blaster, and two Explosive Handlers arrived on 11/15

• 1500 gallon hot water tank and gravity fed hot water drill/hose

• Dyno Nobel Exgel 75 3” x 16” dynamite

• 50-grain detonator cord

Hot Water Drilling

Placing Dynamite

First Blast12/1/10

• The Comms, Sick Bay and the Navy Barracks, or buildings #1, #3 and #4 respectively.

• Forty six (46) holes spaced out 6 feet apart around the perimeter of the buildings

• Averaging 27 ft in depth

• 2552 lbs of dynamite

• 2268’ of 50-grain detonation cord

Blasting Pattern

Blast #112/1/10

Blast #1

Second Blast12/4/10

• The Science, Science Quarters and OIC Quarters and Head Module, or buildings #8, #9 and #22 respectively.

• Forty (40) holes, 6 feet apart around the perimeter of the buildings.

• Averaging 25 ft in depth

• 1760 lbs of dynamite

• 2952’ of 50-grain detonation cord

Blasting Pattern

Blast #212/4/10

Blast #2

Third Blast12/7/10

• The Galley, Post Office and Shops, or buildings #5, #6 and #7 respectively.

• Sixty seven (67) holes, 6 feet apart around the perimeter and in between buildings.

• Averaging 27 ft in depth

• 3344 lbs of dynamite

• 4620’ of 50-grain detonation cord

Blasting Pattern

Third Blast12/7/10

Blast #3

Aerial of Old Pole Area2/5/2011

Questions?