There are two parts to this requirement: the pick off rescue, and the combined descent past knots to the ground or elevated platform. The knots you'll be passing could be tying two ropes together, or simulating rope damage. Do not use them as a connection point at any point during this exercise.

It is your responsibility to complete both portions of this rescue safely, quickly, and efficiently, using good casualty management.  

During your SPRAT Evaluation, L2 and *L3 techs (see below) will be asked to perform a pick-off rescue of a casualty suspended in either ascent or descent mode. You will then need to descend with the casualty, negotiating past knots that've been tied into the main and backup ropes at a similar height -- 2 m above grade, and at least 60 cm below the casualty. 

Whether your casualty is in descent or ascent mode will be up to your SPRAT Evaluator. If they're in ascent mode, you'll need to perform a changeover as part of this rescue, moving the casualty from ascent to descent mode using their equipment. Get yourself as close to the casualty as possible to do this safely.

To successfully complete this requirement, SPRAT doesn't want you to simply find a way of bypassing the knot obstacle using, for example, a pre-rigged to lower system or installing extra ropes to bypass the obstacle. Your Evaluator wants to know that you can maneuver yourself and a casualty past an obstacle using only yours and the casualty's personal protective equipment (PPE).

• Do not use either knot as a connection point. The knots used for this exercise may be simulating a damaged section of rope, you have to use your imagination a little. 
• Practice good casualty management and are aware of the dangers associated with suspension intolerance.

This requirement is most often completed by off-setting the knots and the addition of a second descender; though there a multitude of different methods depending on the situation. Ask your instructor about the pro's and con's of each method.

 

You may find it helpful to review the techniques that were introduced as part of the L1 rescue scenario, as there is some carry over. Specifically, this beginner rescue introduced the techniques needed to rescue a casualty located in close proximity to a knot. 

 

To demonstrate this maneuver, one of your classmates may assist you by taking on the role of casualty and feigning immobility while in suspension. We'll remind you of all this again as you train with us, but if you're playing the role of 'casualty', please remember to keep your legs moving to prevent the onset of symptoms associated with suspension intolerance.