Equipment

IDDO maintains and operates existing drills and borehole logging winches, and develops new systems with two principal foci:

  1. to provide high quality ice cores, and
  2. to produce boreholes that provide access to the interior and beds of ice sheets and glaciers for such purposes as embedding instruments, collecting gas samples, setting seismic charges, studying subglacial processes, studying subglacial geology, collecting subglacial bedrock core, and borehole logging.
 

Rapid Air Movement (RAM) Drill

The RAM Drill was developed for a particular seismic program. It is a system in which high-velocity air drives rotating cutters and blows the ice chips from the hole. The cutting drill motor hangs on a hose that carries the air from the surface and is reeled out as the hole deepens. It has been used three times in West Antarctica, most recently during the 2009-10 field season, when it routinely attained depths of 90 meters. The Askaryan Radio Array (ARA) project, funded by NSF-OPP, borrowed the drill for the 2010-11 Antarctic field season to test methods of producing holes for radio antennae at South Pole, but could not get deeper than 63 meters at that location.

In response to requests by the science community, IDDO worked with IDPO and community scientists to define the science requirements for intended modifications and upgrades to the RAM Drill system. The requirements target a system capable of drilling as fast as the existing RAM Drill, but at a small fraction of the drill's current system weight.

Status (modified/upgraded RAM Drill)

In Development - IDDO engineers are currently working on the conceptual overview for the modified/upgraded system, envisioned to have scalable components for either shallow (~40-meter depth) deployments or for full 100-meter depth deployments.

Science Requirements

Background
The IDPO Long Range Science Plan 2016 identified science goals for ice drilling that spanned a wide range of science targets. For field projects with limited logistical support where geophysical information is needed, an agile, scientist-operated, shot hole drill is needed to rapidly create holes in firn to depths of approximately 40-100 m depths. From discussions organized by IDPO with iterative discussions between IDPO, scientists, and IDDO staff, the following are the science requirements for the drill.

Science Requirements

  1. The Drill should produce holes in firn for a 10 cm nominal hole diameter in the top 40-100 m of a wide variety of firn types, including use in West Antarctica or Greenland. A minimum hole diameter of 7.5 cm is needed, in order to freely pass a cartridge of 5.5 cm diameter and 124.5 mm long to the bottom of a hole that is 100 m deep. The system may include modular hoses/winch/compressor subsystems to allow for access to either only the top 40 m, or to drill to the full max depth of 100 m, with reduced logistics needs for the 40 m system configuration.
  2. The goal for the drilling rate should be to produce 15 ten-centimeter diameter holes to 100 m depth in 6 hours or less of drilling (not including drill transport time between sites). The longest acceptable drilling time per 100 m hole is 40 minutes.
  3. The drill should have stand-alone capability for operation at small field camps at remote sites with no heavy equipment.
  4. The drill should be operable in cold ambient temperatures down to -30 C (± 5 C) and winds of up to 25 knots. The firn and ice are expected to be frozen.
  5. Drilling depth should be available during drilling.
  6. The modules for transport shall be sized appropriately to be easily handled by 2 people with loading assist equipment provided with the drill. The goal for the total system weight with aircraft packaging is to be less than approximately 4,000 lb.
  7. The drill should be very field portable, with the ability to be towed over rough terrain. It is a goal that the 40 m system should be towed ideally by a single snowmobile, and the 100 m system towed by several snowmobiles or by a Tucker.
  8. If towing the 40 m system by a single snowmobile is not achievable, then a modular system is desired that be easily separated for transport (and subsequently reconnected). Consider a "power plant/ compressor" sled and a drill sled that are only connected by few hoses/cables.
  9. The drill control should be simple and intuitive for use in the field by a scientist who has had training before going into the field. Two personnel (one trained and one other) should be able to set up and do the drilling operations in the field.
  10. Setup time for the drill should be within 8 hours after initial unpacking on site.
  11. Drill operations shall be such that two fit people can raise and lower the hose and drill head for a full day without excessive fatigue. Consider providing a mechanical assist to lessen fatigue during drilling operations.
  12. Drill storage in the field at the end of the day should be planned and designed, in the case of an anticipated storm. The SOP should be designed for storms with 30-40knot winds and blowing snow.
  13. The drill should be maintainable in the field by scientists, and instructions and parts for maintenance in the field should be included with the drill.
  14. No more than 1 drum of one type of fuel should be required for 12hr operation.
  15. Engineers should design an SOP for retrieving stuck drills or clogged exhaust hose. Possible ideas may include glycol bombs, or attaching a bullet heater to the air line, or heat tape integrated in the hose and head that can be turned on in an emergency, or other. The generator must be appropriately sized for these emergency situations, or else include a requirement for a 2nd "emergency/backup/spare" gen. A failure mode and effects analysis shall be performed and the drill system shall include documentation, tools, equipment and spare parts required to address high-risk situations in the field.

Notes:

  1. During the development of the Science Requirements, this drill was called the "Agile Shot Hole Drill" but has been renamed to "RAM" drill since it is an update of the older RAM drill.
  2. This drill is intended to perform at all depths up to 100 m in conditions West Antarctica and Greenland; it is intended to replace the existing IDDO RAM Drill.
  3. If fuel consumption is 3 gallons or less per hole, then a single drum of fuel (400 lb) would suffice per day.
  4. Chris: A commercially available 100m compressed-air exploration rig weighs a minimum of 10,000lbs. As a point of reference, a Skidoo traverse capacity benchmark is 2,000 lbs total pulled on two Siglin sleds. With two Skidoos this is only 4,000 lb capacity for both equipment and fuel. So, it seems likely a Tucker will be required to keep number of operators to 2 without shuttling back and forth.
  5. Chris: Air Compressors will be our challenge in this regard. RAM compressors weigh 6000lbs ea. We've looked into an exploration drill rated to 100m using double walled tube. It uses 2000lb compressors.
    http://northspan.ca/Portals/Northspan/documents/drills/Northspan%20Hornet%20Product%20Sheet2.pdf There is a practical limit of the extent to which we can break these into smaller units without making the system overly complex and prone to issues. BAS has 1000 lb modules on their hot water drill that are loaded or unloaded from a Twin Otter with a ramp and hand winch (photo) while a Helo Sling-load can accommodate up to 2000lbs.
  6. Sridhar: I think the Twin Otter/Helo capability will be difficult. If the "lighter" (4000 lb) drill can be designed and arranged for Tucker towing, that might be a great start. The current weight (and the "option 1" weight) of 10+ klbs is heading towards 2 LC-130 flights. The 4-5klb system would allow for 1 flight. Of course the Tuckers would be needed unless Chris has some good ideas on bringing the drill down to 1000 lb components --then skidoo towing by 4 skidoos may be possible, but I would want to see the tradeoffs in complexity and risk with the plumbing having to be re-made every hole.

Associated Documents

Questions or Comments

Questions or comments should be sent to Mary Albert.

Photos

The following photos are of the original RAM Drill, and do not reflect the intended modifications and upgrades to the drill system.


IDDO driller Mike Jayred tests the RAM Drill during the 2010-2011 field season for the Askaryan Radio Array project at South Pole. Photo: Michael DuVernois

IDDO driller Mike Jayred tests the RAM Drill during the 2010-2011 field season for the Askaryan Radio Array project at South Pole. Photo: Michael DuVernois

IDDO driller Mike Jayred operates the RAM Drill at WAIS Divide, Antarctica, during the 2009-2010 field season to quickly produce shot holes for seismic investigations. Photo: John Fegyveresi

The RAM Drill at WAIS Divide, Antarctica, during the 2009-2010 field season. The RAM Drill routinely attained depths of 90 meters during the season. Photo: John Fegyveresi


Equipment Details

The following information pertains only to the original RAM Drill. See the science requirements above for information about the intended modifications and upgrades to the drill system.

Name Rapid Air Movement (RAM) Drill
Type Non-coring
Number in Inventory 1
Max. Practical Depth 95 m (the depth being limited by the length of the hose)
Hole Diameter 100 mm
Core Diameter [not applicable]
IDDO Driller Required? Yes, 2 drillers
Drill Fluid Required? No
Power requirements/source None
Shipping Weight 22,664 lbs
Shipping Cube 2971 cube
Comments Weight of drill system in operation about 20,000 lbs

System Overview

The following information pertains only to the original RAM Drill. See the science requirements above for information about the intended modifications and upgrades to the drill system.


Major system components

  • Two sled mounted diesel engine driven air compressors
    • 400 cfm at 200 psi rated
  • Hose reel sled
    • Integrated drilling platform
    • 100m of 1.5" air hose
    • 6.5 kW generator
    • Spares and tool storage
  • Drill
    • Drills a 4" hole
    • Powered by compressed air

Deployment and Set-Up

  • Requires two plus LC-130 flights not including the tow vehicle
  • Heavy equipment support required to assemble the hose reel on the sled
  • 1.5 days to set up with two people
  • Shipping weight is ~22,664 lbs
  • Weight of drill system in operation about 20,000 lbs
  • Shipping volume is 2971 cubes

Drill System

  • Two 1hp air motors coupled together drive a planetary gear reducer
  • Head spins at 2500rpm
  • Four tool steel cutters
  • Two sets of centering blades
  • Drills a 4" hole
  • Adjustable booster nozzle at the top of the drill
  • Exhaust air ejects the cuttings from the hole
  • Weighs 200 lbs

Operation

  • The rig is rough positioned by the tow vehicle and then drill is fine positioned via an adjustable carriage on the drill sled
  • The speed and direction of the hose reel is controlled via a pendent
  • Ethanol is injected into the air stream to prevent icing in the hose
    • .7 L consumed per 90m hole

Past Deployment

  • 2002-03 season at Onset-D, West Antarctica
    • 226 holes drilled
    • Target depth was 60m
    • Average hole depth was 56m
    • 12,686 total meters drilled
  • 2008-09 season at upper Thwaites Glacier, West Antarctica (traverse from WAIS Divide)
    • 176 holes drilled
    • Target depth was 60m
    • Average hole depth was 46m
    • 8,109 total meters drilled
  • 2009-10 season at lower Thwaites Glacier, West Antarctica (traverse from WAIS Divide)
    • 132 holes drilled
    • Average hole depth was 74m
    • 9,782 total meters drilled
  • 2010-11 season at South Pole to test methods of producing holes for the Askaryan Radio Array (ARA) project
    • Drilled several holes but could not get deeper than 63 m

Performance

  • Capable of drilling to 95m
    • Firn permeability and conditions greatly effect the actual depth possible.
  • 6m per minute maximum drilling rate
  • 25 minute cycle time for a 90m hole
  • ~5 gallons of fuel consumed per hole