IN A MECHANICAL ADVANTAGE SYSTEM
The MPD is designed to function both as a pulley and as a ratchet or
progress capture device in a M/A system. After lowering, there is no need
for a complex changeover between a lowering system and a raising system.
The one-way pulley inside the MPD applies friction during descent control
but serves as a fully functional, high-effi ciency pulley while raising the
load. The MPD effectively locks the rope during pulley system resets with
minimal settling in distance. To convert to an M/A system, simply attach a
rope grab and traveling pulley to the Main Line and a simple 3:1 mechanical
advantage is created. The MPD has a built in Becket that can be used to
attach a change of direction pulley to allow higher mechanical advantage
systems to be built (e.g. simple 5:1 or compound 9:1), thereby eliminating
the need for a rigging plate. This keeps the pulley system neat and clean
with minimal loss of effi ciency.
Simple 3:1
M/A System
Simple 5:1
M/A System
Single
Pulley
Double
Pulley
Single
Pulley
(Parking Brake must be unlocked to load.)
Running End
Load End
REVIEW DIAGRAM
FOR PROPER LOADING
1
ROTATE BACK PLATE
FULLY OPEN
2
INSERT
ROPE
3
Running End
Load End
CLOSE AND SECURE
BACK PLATE
4
Anchor
5
16
INFORMATION
HIGH LINES AND GUIDING LINES
The MPD was specifi cally designed to meet all required functions of a descent
control device, pulley with integral ratchet and belay device. As such, the MPD
is highly versatile for use in many aspects of high-line rigging, including:
•
Guiding-line or high-line track rope tensioning
•
Tag-line management
•
Operating the hoist or reeving lines
For additional information on use of the MPD, instructional videos can be viewed at
cmcrescue.com/videos
.
Additionally, CMC Rescue School provides comprehensive,
hands-on training for all advanced techniques.
For questions or information on training with the MPD, or any other CMC Rescue
product, please call (800) 235-5741 or email
.
CARE AND MAINTENANCE
Clean and dry the MPD after each use to remove any dust, debris or
moisture. Do not store the MPD with equipment where it may be exposed
to moist air, particularly where dissimilar metals are stored together.
User Information shall be provided to the user of the product. NFPA Standard
1983 recommends separating the User Information from the equipment
and retaining it in permanent record. The standard also recommends
making a copy of the User Information to keep with the equipment and
that the information should be referred to before and after each use. The
most current version of the MPD User’s Manual can be downloaded at
cmcrescue.com/mpd
.
Additional information can be found in NFPA 1500,
Standard on Fire Department
Occupational Safety and Health Programs
and NFPA 1983,
Standard on Life
Safety Rope and Equipment for Emergency Services
.
To rig the MPD, fi rst ensure that the Parking Brake is unlocked. Hold the
MPD so that the back plate faces up. Take note of the diagram showing
the proper rope orientation, then open the MPD by rotating the back plate
clockwise until there is suffi cient space to insert the rope between the fi xed
and moving friction brakes.
Insert the rope with the running end between the friction brakes and place
the rope around the pulley in a clockwise direction. The load end of the rope
exits the pulley opposite the friction brakes. Close the MPD by rotating the
back plate completely counterclockwise, making sure that the rope properly
enters and exits the MPD as shown in the diagram on the back plate. Attach
the MPD to the anchor using an appropriate locking carabiner or screw link
through both the front and back plates.
PARKING BRAKE
A unique feature of the MPD is the Parking Brake, which when locked,
prevents inadvertent letting out of the rope. The design of the Parking
Brake allows for rope to be taken in if required without having to unlock it,
although increased rope friction will be encountered. Lock the Parking Brake
prior to releasing your grip from the running end of the rope, except when
the MPD is rigged as a ratchet or progress capture in a pulley system. For
example, once the rigged MPD is connected to the anchor, for safety, lock
the Parking Brake until you are ready to use the device. To fully lock the
Parking Brake when using untensioned, icy or saturated rope, it may fi rst be
necessary to pull out the Release Handle and rotate it clockwise to further
force the Moving Brake against the rope.
THE MPD
ABOUT THE MPD
17
4
