CRREL recovers Jeep from frozen lake
Article and Photos by
Maj. Michael Meeks
Cold Region Research and Engineering Laboratory (CRREL) personnel
recently recovered a wrecked vehicle from a deep frozen lake.
Last winter, a CRREL contract employee was driving a government-owned
Jeep Cherokee along the Glenallen Highway in central Alaska when he lost
control and plunged 80 feet over a cliff. The vehicle rolled several
times, landed in the lake and sank in the frigid water.
The driver's seatbelt saved him from serious harm. He managed to
unfasten his seatbelt, swim to the surface, and back to the bank. He
climbed up the snow-covered cliff, walked down the highway, and was
picked up by a passing motorist. He suffered a small cut on his cheek,
ruptured eardrums from water pressure, and hypothermia.
Months later, the Jeep was recovered from 40 feet of water under four
feet of ice. CRREL employees and the Arctic/Subarctic Aquatic Pararescue
Group (ASAP) managed the recovery.
|A diver enters the lake. The ice
is 48 inches deep.
The Jeep was removed from the lake for environmental reasons. The
General Services Administration, who owned the Jeep, planned to contract
the recovery to a private contractor, but CRREL felt they could recover
it at lesser cost and wanted the challenge. Plans were made and ASAP
agreed to lead the extraction team.
Underwater topographic maps showed the lake was up to 90 feet deep
with a steep underwater slope. The slope of the shoreline was too steep
to use a vehicle on the slope or on the road 80 feet higher.
By springtime the lake was frozen solid. The initial plan called for
cutting a small hole through the ice so divers could go down to locate
the vehicle. Chainsaws would cut away large sections of ice next to the
shore, allowing cables to be attached to the Jeep. Divers using lift
bags would raise it off the bottom. As people on the shore hauled the
cables, divers would maneuver the vehicle toward the opening.
Change of plans
But reconnaissance showed that the lake ice was thick enough to
support heavy vehicles, so CRREL changed plans to extract the vehicle
through the ice. ASAP provided diving equipment, rigging, medical
equipment, and expertise. Paramedics were on the scene and they
developed a detailed dive plan and adhered to it. The volunteers
assembled at Lake Long from around Alaska.
When we arrived, we found the ice thickness had been underestimated.
Instead of 18 inches, it was 48 inches thick. This was due to high winds
which sweep the ice clean of snow, allowing it to freeze thicker than
surrounding snow-covered lakes.
Cutting the first section was a tedious process. We cut the first
section for the dive with two chainsaws, one with a three-foot bar, the
other with a four-foot bar. The first section took four hours of
cutting, prying, and smashing ice. As the ice was cut, divers in
insulated suits wedged the pieces under the ice sheet.
The ice-cutting went much slower than expected due to the ice
thickness. Chainsaws froze up in minutes after getting wet. We set up a
heater and the chainsaws were alternated in front of it to thaw every
time one froze.
The first diver finally went through the dive hole to locate the
wreck. A second diver stood by as an emergency back-up. The depth
directly under the opening was 60 feet, sloping to 90 feet. Due to the
altitude (2,000 feet above sea level), the divers' bottom time was
reduced to 15 minutes.
Within minutes after starting his search, the diver located the Jeep
in 40 feet of water. It was lying on its side, hung up on a large
boulder. If the vehicle was not handled properly, it could slip off the
boulder and slide down the incline, crushing any diver under it.
Once the first diver was topside, a second diver went in to mark the
site so a hole could be cut directly over the vehicle. The ice was so
clear that it was easy to watch the diver as he moved underwater. He
attached a float to the vehicle; those standing on the ice marked the
float's location, and began cutting the recovery hole.
The divers reported back that attempting to float the vehicle under
the ice to the shore was impossible. It would be extremely difficult to
route the vehicle through the large boulders on the bottom.
But with the ice thickness at four feet, it would be possible to
bring a wrecker onto the lake and pull the Jeep up through a hole in the
ice. Eight hours later, a recovery hole measuring 8x7 feet was finished.
Seven tons of ice had been cut and moved in two days.
The water was so clear that everyone could see the Jeep on the bottom
of the lake once the ice was removed. Two divers suited up using air
supplied from the surface, and a two-way intercom. They carried an
underwater video camera to record the event.
Both divers descended through the dive hole to the Jeep. They
attached a safety line to the vehicle which was secured to trees along
shore to keep the vehicle from sliding down the slope and injuring
|After all winter on the bottom of
a frozen lake, the Jeep finally breaks surface.
There was a wrecker at the site and the divers attached its cable to
the Jeep's axle. Once the divers were back topside, it was all up to the
wrecker. To improve the wrecker's traction on the ice and keep it from
sliding into the hole, we put sand and gravel on the ice. We chained a
second vehicle to the wrecker to provide additional traction.
Then the wrecker lifted the Jeep off the bottom of the lake. As it
neared the surface, large poles were used to pry it away from the
underside of the ice and into the center of the recovery hole.
Once the Jeep broke surface, we allowed the water to drain from it to
reduce the weight the wrecker had to lift. Within minutes the Jeep was
safely on the ice.
Absorbent pads were placed on the water to soak up oil or fuel that
might have been released during the recovery. Warning signs were placed
around the hole so that snowmobilers would stay clear. Much of the ice
that was removed was replaced back in the hole to aid refreezing.
From The United States Army Corps of
Engineer Update is an unnofficial publication
authorized under the provisions of AR 360-81. It is published monthly
for the U.S. Army Corps of Engineers. Editorial views and opinions
expressed are not necessarily those of the Corps of Engineers or the
Department of Defense. Inquiries and comments can be forwarded to editor
of Engineer Update by e-mail to Bernard.W.Tate@usace.army.mil.