technical rescue the objective is to extricate a possibly injured subject from
a precarious situation to a safe location for further evacuation. If possible
when evacuating from a vertical rock face or high mountain situation, a
lowering system which uses gravity to pull the rescue load down is preferred.
A lowering system requires less work from the rescuers than a raising system
and therefore can normally be achieved with less total rescuers. Of course an
evacuation path must exist from the bottom of the evacuation via some sort of
transportation (i.e. litter, ambulance, or SAR truck) once the lowering
systems have been completed.
is any device intended to apply friction to rope for the purpose of slowing or
stopping the progress of the rope travel. i.e. Figure 8's, Rescue 8's, Brake
is the process of securing a brake system in such a way that rope travel is
not allowed in any direction. Also an operator is not required to maintain
pressure or tension while the system is Locked-off.
is the operator's hand that must never leave a rope during a lowering
operation. This is similar to the braking hand used in belays. The intent is
that if the operator has contact with the rope when a sudden surge or load
change occurs, he will able to best respond to the load change if the rope is
guaranteed to be in his hand.
is the operator's hand that is used to monitor the tension of the main
lowering line. Lowering systems are designed to work with the weight of the
load. If slack is formed in the main line this may indicate that the rescue
load has become momentarily hung up on a ledge or is at the bottom. The
operator strives to maintain no slack in the line unless slack is required for
some specific purpose.
lowering systems used by SAR, work in a similar fashion to the rappelling
systems which are based on friction created by bending rope about a device
with a tight turning radius. In this case the braking device is held
stationary and the rope (attached to the load) is allowed to move.
As is the case with all rescue operations, redundant belays are
required in addition to the lowering system. A lowering station can be
comprised of one or more rescuers depending on the load and the amount of
friction being created by the braking device. Lowering systems are designed to
require a minimum amount of force (strength) to operate as the load is held by
the system brake device. The lowering system operators control the speed of
descent and have the ability to "lock off" or stop and secure the
system. Rope management at the scene is important to prevent rope twists and
entanglement from interrupting the flow of the operation. The lowering station
will normally operate under the command of a field manager or an operations
leader. Extreme care must be exercised to watch fingers and loose equipment to
prevent entrapment in the lowering system. If assigned to create and operate a
lowering station, advise the leader of its completion after construction is
finished and stand by the system in a ready state unless advised otherwise.
edge protections, such as edge rollers, should be utilized when available to
protect the rope from abrasion during a lowering operation. If dynamic edge
protection is not available, low resistance protection should be used to
protect the rope from sharp or abrasive rocks. The rope is expected to take
some abrasion against the rock during an operation.
commands are used to control the operation of the lowering system. They are:
Lower away, Faster, Slower, Stop, Lock-off, Convert to Raising, and
Break down. Normal systems protocol allows anyone to stop a lowering system,
but allows only the operation's leader to restart lowering.
brake system has its own requirements which are explicitly specified below.
Additional gear to convert to a raising system, and prussiks should be
available in the event a problem arises with the lowering system.
OF EIGHT LOWERING SYSTEM
team standard lowering brake is the "rescue 8" device which is
normally used for rappelling. The rescue 8 is larger than a normal figure 8
rappel device, has "lock-off ears" to facilitate easier and
more stable lock-offs, and has a extra attachment slot for connection of
an extra person or for use a as a stitch plate. The "rescue 8"
device is shown in figure-1. The rescue 8 may be used with 6 to 13
mm rope with loads up to 1000 lbs. Speed control is managed in the same manner
as is used for rappelling.
slow or stop the load, tension is applied to the free or brake side of the
rope and the rope is pulled at a right angle to the main axis of the figure 8
as is shown in figure-2. Pulling the rope at a right angle to the
major axis of the figure 8 device creates the tightest angle and therefore
applies the most amount of friction. When lowering rescue loads, especially
large loads above 300 lbs, a slow pace should be used. Stops should be applied
gradually if possible to dissipate the energy over time rather than in heat on
a quick stop. Quick stops or jolts always stress a system more than continuous
loads cause an increased amount of heat and may lead to a system failure.
Whenever actively operating a lowering system, the operator should be wearing
leather gloves to protect the hands from injury. (In addition to the
possibility of rope burns, the rope could contains thorns or cactus spikes
which would become embedded in the hands if leather gloves are not worn.
a lowering station will consist of 3 to 4 people based on the number of people
available. One person should be delegated to be responsible for rope
management. Figure 8 lowering systems have a characteristic inherent
disadvantage which is caused by the "spinning" of the rope as it
passes through the brake. This spinning causes tension between the rope fibers
and the sheath which can make the rope hard to handle after 200 to 300 foot
lowering operations. The effects of the spinning can be minimized by loosely
flaking the rope into a large pile prior to feeding it through the brake. If
it is necessary to use several rope lengths, as in one long lowering system,
tie the next rope into the system only when nearing the completion of the
lowering of the previous length of rope. By connecting the lines just prior to
their use, the twist that was accumulated in the first line can be completely
dissipated prior to attaching the next line. Otherwise, if the lines were
connected earlier, the second line would receive twist from the first line. As
a rule never attempt to pass more than 400 ft of continuous rope through a
figure 8 lowering station.
8 lowering systems provides the easiest and most secure lock-off
capability. Lock-offs are requested to place the lowering system in a
locked state where the secured brake is preventing any further lowering of the
system. To lock a rescue 8 one first draws the free end across the top of the
figure eight and across the load side of the rope as is shown in figure-3. This places friction between the two sides of the rope.
prevent the lock from disengaging easily the rope is wrapped around the eight
and a second wrap is placed as is shown in figure-4. (This would
complete the lock-off for a normal figure 8.)
To complete the lock-off when "Ears" are available on
the brake, a bight of the rope is inserted into the eight, and pulled tightly
against the ears as is shown in figure-5. If the lowering system is
to remain locked for an extended period of time, the lowering line (main)
could be secured with a prussik as is shown in figure-6, (Note use
of the mariner's knot) or the main may be knotted and secured as is shown in
figure-7. Knotting the rope or placing a prussik on the main line
should only be used when the lock-off time is not expected to be short.
However, knotting the rope or a prussik back-up is required if the
operator must leave the station for some reason. (Although not preferable, if
a problem arises and the personnel is limited, the lowering system operator
may be required to secure the lowering station and then move to assist in some
other aspect of the operation.
has been mentioned often, the lowering system requires a valid sturdy anchor.
Separate anchors must be used for the different systems in use (i.e. Belay and
Lowering would be separate anchors).
KNOTS WITH A FIGURE OF EIGHT LOWERING SYSTEM
passing is required when a single length of rope will not suffice the
necessary lowering length requirement and additional lowering stations are not
possible or are not desired. Winter evacuation down long low angle slopes
often create demands to lower a litter several thousand feet. Obviously a
rescue team can only carry a limited amount of rope into the field. Team 1 uses
200', 300', 400', 165' (climbing line), and 600' rope spools for operations.
The operations leader will make a decision based on available equipment as to
the length of the lowering station and the position of the lowering stations
if more than one station is required to do the required job.
trade-off between extending the length of a lowering station is not
always clear. The added rope length increases the amount of rope friction if
the station is not a pure overhand, complicates the rope twist problem if
using a figure 8 brake device, and extends the distance between the rescue
personnel at the load and the team at the lowering station. More lowering
stations require additional hardware, additional sites for the stations to be
assembled, additional personnel to man each station, and coordination between
the various stations. Since 200 ft sections are the typical rope length used
in the backcountry, the following guidelines would apply. If the evacuation is
400 ft or less with no change of direction required, then it would be best to
use extended ropes tied together. (Remember in addition to lengthening the
main line a belay will also be doubled.) If
the evacuation is greater than 400 ft and can be completed easily in 3 or less
stations than multiple stations should be used on single length ropes. In
longer evacuations, multiple stations using extended (or knotted) lines will
be required. Passing knots will be required whenever shorter sections of rope
must be joined to form one usable length of main line.
are two methods approved for use on SAR to pass knots in a lowering system.
The first method uses the belay to momentarily hold the load while the knot on
the main is passed through the brake. (Likewise the main will hold the load
while the belay line knot is passed through its belay brake.)
It is important to note that the knot is passed through the system
brake. The brake is still fully operational except that slack has collected in
the area of the brake assembly. If the belay were to fail, the load would fall
completely on the main lowering brake regardless of the position of the knot
with regards to the brake. It is NOT allowable in this case to disconnect the
main brake to facilitate passing the knot through the brake device. If the
knot cannot be passed through the brake device then another technique for knot
passing must be used. Extreme care must be used to protect the fingers from
entrapment in the brake.
operation can be done smoothly with no interruption in the lowering flow or
can be done in sections by first locking the belay, passing the knot, lowering
the belay, and re-assuming the load with the main line. This sequence is
depicted in figure-8. For successful and safe operation the system
should not arrive at knots on the belay and main line simultaneously.
knots through load transfer to the belay line as is described above has a
disadvantage of placing slack in one line which will allow a drop in the load
in the event of a failure with the other line. Keeping the amount of slack,
and the exposure time to a minimum when the slack is present, minimizes the
risk to the operation. Load transfer to belay simplifies the knot passing
operation and allows the knot to pass quickly.
second way, the redundant brake method, is used to pass a knot when personal
is limited, when any slack is not acceptable in the system lines due to the
integrity of the available anchors, or when the knot will not pass through the
brake unless the brake is disconnected. The redundant brake utilizes a second
brake, an ascending device (Gibbs or prussik), and an extra section of rope
(typically 20 to 50' long). When knot passing will be required, the rope shall
be fed through the redundant brake with the running end connected to the
ascender as is shown in figure-9. When the knot to be passed
approaches the brake, then the ascender must be attached to main lowering line
on the load side of the brake. Tension is then applied to the redundant brake
until the load is transferred completely to the redundant brake. After the
redundant brake has assumed the full load, the knot may be passed through the
brake. Since the redundant brake is applied, the primary brake may be removed
to facilitate the knot passing. Also since no slack is ever generated in
either belay or main lines the result of a single line failure will not highly
stress the anchors. Since the redundant brake or the primary brake will
alternately assume the load, the redundant brake may utilize the same anchor
as the primary lowering system. (It may also have its own anchor if desired.)
The sequence of using the redundant brake is shown in figure-10.
alternate and equally safe method of applying the redundant brake is shown in
figure-11. In this application, the rope is fixed to the anchor
using a knot and a carabineer. The ascender is attached to the brake device. The
redundant brake operator will then follow the redundant brake
as the load is lowered. The benefit to this style of application is
that the redundant brake operator is operating away from the rest of the
system which may be beneficial if space is limited. Also the operator is close
to the main line attachment area to easily remove the ascender when transfer
back to the main line is complete.
using Gibbs ascenders as the ascending device, the rule "Keep the fat end
of the ascender towards the anchor" applies. This is highlighted in
figure-12. When the redundant brake is not required the complete
knot passing assembly should be clipped into the main anchor so it will be
available and ready to go when it is needed.
SYSTEM LINES ONTO ANOTHER LOWERING STATION
major concern of the operations leader is to have the proper rope at the
proper site when the lowering is required. In long lowering operations, rescue
loads (litters etc.) may be passed from one lowering station to the other. It
is easiest and rope efficient to pass the lowering lines along with the rescue
load as the operation progresses. In this manner, the same main and belay
lines will be used by each station to lower the load. This type of rope
passing may be used on low and high angle operations. It is always best to
rest the load on a surface during rope transfer. Many evacuations do not offer
appropriate ledges or caves when the end of the rope is reached and therefore
rope transfer will occur with lowering lines fully loaded.
Figure-13 illustrates the situation where the rescue load will be passed
from lowering station "A" to lowering station "B."
In anticipation of accepting the rescue load from station "A"
above, station "B" should prepare the anchors needed for belay and
lowering. (This chapter highlights the lowering system specifically but notes
the importance of the belays that are also used.)
The personal at station "B" assist in passing the load past
station "B" with the load still being controlled by lowering station
"A." When the load has
passed station "B," progress of the litter shall be halted. Under
communication from the operations leader, the main line is slacked to place
the load on the belay line. (Note: That
station "A" is slacking its line but still maintaining the rope in
the brake which is needed in the event of a failure of the belay line.)
With slack in the main line, station "B" inserts the main
line into its lowering brake and places tension on the load. The belay line of
station A should be slowly lowered until the main line of station B has
assumed the entire load. Again, with coordination through the operations
leader, the same procedure is implemented for the belay line. With station
"B" now in full control of the rescue load, the main and belay line
may be released from the brake and belay at station "A."
In vertical operations care must be taken to toss the line to the sides
of the lowering station below. Personnel at station "B" should
protect themselves and the subject being lowered from any rock or rope fall
that may occur. In low angle operations the rope will just follow along the
ground, which helps to alleviate rope twist if a figure 8 brake device is
an added safety feature, the station accepting the load could have a third,
redundant anchor and a short rope section to place the litter in a local
locked position while the rope transfer is being made. This provides an added
level of security especially when communications are poor as may be the case
during a high wind, snowy, night operation.
operations where it is not feasible to pass the lowering lines from one
station to another, the following transfer technique should be utilized. (This
may be needed when multiple subjects must be lowered individually down a long
evacuation or when the line are needed to extricate the rescue team.)
In this case, the receiving station should have the lowering and belay
lines ready with carabineers attached. The receiving station should have a third
redundant anchor to stabilize the load during the transfer and to operate as
an extra belay in the event of a problem or a human error. After again
allowing the load to pass the receiving station, the redundant anchor is
attached and tensioned. This anchor should be attached to the load in a
location other than the harness that is being used for the primary system.
(This creates redundancy in an area that will not be affected by the
transfer.) The main lowering and
belay lines should then be attached to the system harness and tensioned. Slack
should then be placed on the lowering station above to fully transfer the load
onto the lower station. The main and belay lines from the station above may
then be released. One person should open and remove one carabineer at a time to
minimize any confusion. (It may seem that a few extra hands will speed the
transfer, but it is imperative that the correct cararbineers be removed.)
The extra third safety line should be removed prior to continuing with
the lowering station.
OF THE LOWERING SYSTEM TO A RAISING SYSTEM
members should be able to effectively and quickly convert lowering systems to
raising systems and the reverse. This may be needed if the load were lowered
into an obstacle or a hazardous area that was not seen from above. The actual
technique is dependent on the type of raising system that is employed, but the
task required is the same. First the lowering station will be
raising system would then be attached to the main line. The lock-off
mechanism for the the main line would then be placed on the rope closer to the
load than the existing brake. Tension is then released on the brake to
transfer the load to the lock-off device of the raising system. The
lowering station brake is then removed and attached to a service loop in the
anchor or other place where it will be available if the lowering station is
AVAILABLE LOWERING DEVICES
Rescue 8 (figure 8) is the primary brake for use on Team1 operations. Limited
gear may force the member to utilize an alternate brake system. Also other
teams use different types of brakes which should be familiar to the Team1 member to allow joint operations to run smoothly.
a large rescue load must be lowered by a few rescuers manning the lowering
station double rescue 8's could be used to form tighter rope turns, additional
friction, and more control. Doubled 8's are applied by placing one 8 on top
the other and treating the two 8's as one. A large diameter carabineer is required
to attach the 8's as is shown in figure-14.
braker bar which is an aluminum bar designed to slip over the gate of a
non-locking carabineer is shown in figure-15. The friction is
generated by the rope passing under the carabineer, over the braker bar, and then
back under the carabineer. The benefit of the braker bar is that it makes a brake
out of a simple non-locking carabineer (which are not always available in
rescue work). Another advantage is that the braker bar does not twist the
rope. Care must be taken to place the bar in the proper orientation, as it
will fail completely if attached improperly. A braker bar rack is and aluminum
or steel bar containing several (5 to 8) braker bars.
arrangement is popular in cave entrances and long vertical wall rappels and
lowering stations. The multiple braker bar arrangement allows a wide variance
in friction and control. The braker bar rack is shown in figure-16.
properly adjusted, the operator should be able to control the descent of even
large loads with relative ease. The bars must be attached in the proper
direction or the rack will fail completely. Also if tensioning is required,
(as is needed sometimes at the beginning of a lower when the load decides to
return to the top) reversing the direction of the rope flow is very difficult.
Breaker bar racks are extremely useful for long lowering operations (1200 ft)
with single or joined ropes since the rack does not twist the rope.
provisionary mode braker bar arrangement can be created by using two locking carabineers (or four non-locking)
carabineers as shown in figure-17. One carabineer acts and functions as the braker bar. This
carabineer brake arrangement can
be applied in series much like the braker bar rack assembly. A six carabineer brake
is shown in figure-18. The main advantage of the carabineer brake is that
it requires no special equipment (only carabineers) to implement.
Military Wrap on a carabineer may be used the same as it would be for rappelling.
Care must be used to guarantee that the rope does not walk up and open the
locking carabineer. The rope should be attached as is shown in figure-19.
The amount of friction increases with the number of wraps that are placed
around the carabineer.
short operations or severe emergencies such as escape from a burning building,
the munter hitch may be used as a lower system. Figure-20 indicates
the use of a pole and a munter hitch as an emergency brake for a lowering
braker bar, the braker bar rack, the carabineer brake, the military wrap, and the
munter hitch do not provide a simple and reliable means to lock- off the
lowering system. For this reason the operator should have an ascender and an
extendible webbing section (such as a mariners knot) to lock-off the
lowering system if the need arises.