week 4 (chapters 8-9)

Question 1

what are parted blocks used for?

Answer 1

sag conductors, set poles, hang pole line equip

Question 2

where would you find a becket?

Answer 2

on a set of parted blocks

Question 3

where do you find the weight rating on blocks?

Answer 3

stamped on the hook or shell

Question 4

parted blocks provide a _______?

Answer 4

mechanical advantage

Question 5

parted blocks ______ the load between parts of the rope

Answer 5

divide

Question 6

when a load is suspended with two slings the load on each sling is ____ of the total load being lifted

Answer 6

half

Question 7

when a set of parted blocks is used, the force required to hold the static load is ______ __ ___-?

Answer 7

cut in half

Question 8

what are the two main tensions involved with parted blocks that are important to understand?

Answer 8

haul line
hook strain

Question 9

calculated to verify that the WLL of the rope, and the hoisting mechanism is not exceeded?

Answer 9

haul line

Question 10

calculated to verify that the WLL of the blocks is not exceeded.

Answer 10

hook strain

Question 11

for every sheave a rope passes through, ___ friction is added to the weight applied to the rope

Answer 11

10%

Question 12

after _____ parts, the friction is greater than the mechanical advantage and the haul line tension begins to rise

Answer 12

10

Question 13

amount of mechanical advantage gained is dependent upon the

Answer 13

number of parts

Question 14

what is the formula for haul line tension?

Answer 14

haul line = 1.1p x W / P
* p is the exponent of 1.1

Question 15

when does the greatest mechanical advantage occur?

Answer 15

at 2 parts, haul line tension is nearly cut in half

Question 16

haul line tension + weight of load = ?

Answer 16

hook strain

Question 17

commonly used in transmission lines to redirect rope in different rigging situations?

Answer 17

snatch block

Question 18

snatch blocks can open near the ______ to trap a bite of rope

Answer 18

swivel

Question 19

where is the weight rating stamped on a snatch block?

Answer 19

hook or shell

Question 20

if snatch blocks don’t have a weight rating tag you should?

Answer 20

remove it from service

Question 21

tension placed on a snatch block is dependent on what?

Answer 21

angle the rope is passing through the block

Question 22

when the angle on a snatch block decreases, the tension ______?

Answer 22

increases

Question 23

whenever a line passes through a block there is ______?

Answer 23

friction

Question 24

tension, which depends on the angle for determining the exact amount, is applied to the line ____ not the line _____?

Answer 24

out/in

Question 25

a line fixed to a load of 100 pounds, running through a snatch block at 90 degrees will have a tension of?

Answer 25

110 pounds (line out tension = line in x 1.1)

Question 26

how do you calculate snatch block tension

Answer 26

snatch block tension = line out tension X angle factor

Question 27

a line angle of 180 deg through a snatch block has an angle factor of _______?

Answer 27

0

Question 28

a line angle of 120 deg through a snatch block has an angle factor of _______?

Answer 28

1

Question 29

a line angle of 90 deg through a snatch block has an angle factor of _______?

Answer 29

1.41

Question 30

a line angle of 60 deg through a snatch block has an angle factor of _______?

Answer 30

1.73

Question 31

a line angle of 45 deg through a snatch block has an angle factor of _______?

Answer 31

1.84

Question 32

a line angle of 0 deg through a snatch block has an angle factor of _______?

Answer 32

2

Question 33

calculate the SBT (snatch block tension) of a line through a block with an angle of 90 deg, and a 1200 Lb load.

Answer 33

1) first find line out tension ( 1200 X 1.1 = 1320)
2) plug into formula ( SBT = 1320 X 1.41 ) *1.41 is the angle factor
3) solve ( STB = 1861.2 Lbs

Question 34

snatch block tension is important because it determines what three factors?

Answer 34

size of block
size of sling
size of anchor point