Water Rescue

Question 1

Water safety code for education

Answer 1

S- Spot the dangers
A- Take advice
F- Go with a Friend or Family member
E- Learn what to do in an emergency

Question 2

River Orientation
If you are standing upstream of a river (where water flows from - to)

1) where is river left located
2) where is river right located
3) where is downstream located

Answer 2

1) Looking downstream, river left is to the left
2) River right is to the right
3) Downstream is wherever the water is flowing to

Question 3

What are some of the variables that affect water ?

Answer 3

1) Volume - The larger the amount, the greater the force

2) Gradient - The steeper the gradient , the faster the flow of water will be

3) Obstacles - Create water features and hazards E.g. eddy, eddy fences and cushion waves

4) Topography - Rise and fall of the land ( water will always navigate to lowest point )

5) Ground saturation - Excessive saturation will stop water from being absorbed and cause it to overflow

6) Rainfall Intensity - Concentrated rainfall in one area can cause flooding)

7) Water management systems - If they are blocked or excessive rainfall, they will not cope

Question 4

How do you calculate the channel volume of a body of water

Answer 4

(Volume is measured in cubic meters per second cms-1 or cubic feet per second cfs-1)
(1 cms-1 = 35 cfs-1 = 1 Metric tonne per second (1 cumec))

Volume = Width(meters) x Depth(meters) x Speed(meters per second)

Question 5

What is square law

Answer 5

Force obeys square law i.e.

Double the speed, 4x the force
Triple the speed, 9x the force
Ten times the speed, 100x the force

Question 6

What are the different flows

Answer 6

Laminar

Helical flow

Question 7

What is laminar flow?

Answer 7

Laminar flow is when water is organised in parallel layers and moves in an orderly manner

Water will be quickest at the centre and near the top due to friction loss on bottom and sides

Question 8

What is Helical flow

Answer 8

Helical flow is a spiralling of water caused from the banks slowing the water at the edges whilst there is fast flow in the middle.

The can cause debris/casualty/rescuer to be pushed inwards from the banks

Question 9

What is current vector?

Answer 9

Water will always try to travel in straight lines. This direction of flow is called CURRENT VECTOR

Question 10

How long are the throwlines

Answer 10

20meters

Question 11

Whats the static breaking strength of a throwline

Answer 11

10 Kilonewtons

Question 12

What water rescue equipment do we have on the TRV?

Answer 12

2 Crew saver life jackets
1 20meter throwline

Question 13

What’s the hierarchy of water rescue methods

Answer 13

Shout
Throw
Row
Go
Helo