Technical Evacuation SystemTechnical Evacuation System

TES - Reasoning• When a rope is necessary or desired to

ensure safety of the rescuer or patient• All evacuation systems use an anchor system

with a raising and/or lowering system• Belay on separate anchor is used if main line

failure would cause injury to rescuer or patient• Rescuer should never become a link in the

system but should only control the system

TES - Components• Lowering system

1. Braking devices

2. Rigging a litter for lowering

3. Lowering a person without a litter

4. Passing a knot

5. Loading patient while on a ledge or suspended

TES - Components• Raising system

1. Mechanical advantage systems

2. Passing a knot

3. Raising a person without a litter

TES - Components• Belay system

1. 540 device

2. Separate anchor system

3. Plan for shock load

4. Tandem prusiks

5. Load releasing hitch

TES - Components• Highline

1. High strength anchors

2. Load assessment

3. Kootney highline

4. English reeve

5. Offsets

TES - Components• Communications

1. Commands (down, raise, slow, stop, tension)

2. Anyone can say stop

3. Only IC can issue down or raise command

TES - Components• Safety

1. Belay attached to litter, patient, and attendant

2. Rock or ice fall protection

3. Rope edge protection

4. Getting over the edge

5. Fixed line for working near the edge

TES - Standards• Newton

1. Measure of force used to move a 1 kilogram (kg) object 1 meter (m)

2. One kilonewton (Kn) is 225 pounds (lb) of force

TES - Standards• Rescue load

1. Two kilonewtons or 450 pounds

2. Accounts for patient, rescuer, personal and system gear weight

TES - Standards• Safety factor

1. Ten to one (10:1)

2. Given a rescue load of 450 pounds and a safety factor of ten to one, all individual components of an evacuation system that might be required to hold a rescue load force should have a minimum breaking strength (MBS) of 20 kN or 4,500 lbs

3. To stay within the 10:1 safety margin, evacuation system forces should not exceed 2 kN or 450 lbs

TES - Anchors• Main and belay are separate anchors• Use large, natural anchors if possible• Evaluate material where anchors are located• Evaluate for direction of pull and strength• Approach all anchors with skepticism• Monitor anchors throughout operation

Anchors – Wrap Three Pull Two (W3P2)1. 1” tubular webbing is 18 kN (4,000 lbs) per strand

2. Water knot is isolated, does not reduce strength

3. MBS about 70 kN (15,750 lbs) with angle < 30°

Anchors – Distributed (Not Equalized)1. ABC 8mm cord is 14 kN (3,150 lbs) per strand

2. Figure 8 cluster and double fisherman knots reduces strength by about 20%

3. MBS of abut 60 kN (13,500 lbs) with angle < 30°

Lowering System – Main Line• Six bar brake rack and locking carabiner• Easy to add or remove friction under load• Does not twist rope• Use 11mm (7/16”) static rope• Tie off brake rack when stop is called• Do not use any hard rope grabbing devices

Lowering System – Main Line1. ABC 11mm polyester static rope is 40 kN (9,000 lbs)

2. SMC aluminum carabiner is 36 kN (8,100 lbs)

3. SMC brake rack is 44 kN (9,900 lbs) but can break rope at 26 kN (5,850 lbs)

Lowering System – Main Line1. Tie off brake rake with two wraps around bars and half hitch with overhand knot on rope

Lowering System – Belay Line• 540 belay device with locking carabiner• Separate anchor system that is away from

main line anchor system• Use different color 11mm (7/16”) static rope• If a 540 is not available, use a tandem prusik

system attached to a load releasing hitch• Tie off 540 device when stop is called• Do not use any hard rope grabbing devices

Lowering System – Belay Line1. ABC 11mm polyester static rope is 40 kN (9,000 lbs)

2. 540 device is 36 kN (8,100 lbs)

3. SMC aluminum carabiner is 36 kN (8,100 lbs)

Lowering System – Belay Line1. Tie off 540 device with a half hitch with an overhand

knot on the rope

Lowering System – Tandem Prusik1. ABC 8mm cord is 14 kN (3,150 lbs) per strand

2. Double fisherman knot reduces strength by 20%

3. Figure 8 knot reduces strength by 25%

4. SMC aluminum carabiner is 36 kN (8,100 lbs)

5. SMC single sheave pulley is 49 kN (11,025)

Lowering System – Tandem Prusik1. Radium load releasing hitch starts with a figure 8 on the load carabiner, follow with two wraps of the cord, add Munter hitch on anchor carabiner, tie off the hitch with a half hitch and an over hand knot

Lowering System – Tandem Prusik1. Use two different colored and length prusiks

2. Use prusik minding pulley if available

3. Tie off end of Radium load releasing hitch cord

Raising System – Main Line• Use a 5:1 pulley system with two double sheave pulleys attached to the main anchor• Haul rope is usually dynamic climbing rope• Pull the haul rope away from the edge• Attach the load side of the pulley system to

the main line using a quick release prusik• The brake rack is replaced with a dog and

tails hitch on the main line• More mechanical advantage means less

travel and more resets

Raising System – Main Line1. Water knot reduces strength by 40% to 50%

2. Dog and tails extender is 18 kN (4,000 lbs)

3. SMC double sheave pulley is 49 kN (11,025)

4. 8mm prusik loop is 22 kN (4,950 lbs)

Raising System – Main Line1. Quick release prusik will slip on main line at about 9

to 13 kN (2,025 to 2,925 lbs)

Raising System – Belay Line1. The raising system for the belay line does not change for either the 540 device or the tandem prusik setup

Attaching To The Main And Belay Line1. At the end of both the main and belay line, tie a high strength bowline and a 10 foot tail ending with a figure 8 knot

Attaching To The Main And Belay Line1. High strength bowline reduces strength by 20%

2. 11mm polyester static line is 40 kN (9,000 lbs)

3. At the bowline, static line is 32 kN (7,200 lbs)