Superstructure Assembly and Erection Part 2

Question 1

The winch and stinger can lift loads in certain positions that will overload the boom.

Answer 1

True

Question 2

Damage to the rotation gear of a digger derrick can be caused by ? .

Answer 2

operating a heavy load with the truck set up on a slope

Question 3

The lifting capacity of a digger derrick is decreased when ? .

Answer 3

the boom is extended away from the turret

Question 4

The lifting capacity chart for each digger derrick must be ? .

Answer 4

visible from the boom operator’s position

Question 5

On a digger derrick, the stinger will not extend if the overload protection is working.

Answer 5

True

Question 6

The lifting capacity changes with the direction of the boom in relation to the truck, outriggers, and slope of the ground. A typical chart will show a ? rating when operating the boom over the side and at a 5° slope.

Answer 6

60%

Question 7

The maximum working load for a one-inch double-braided polyester winch rope is ? .

Answer 7

6,000 lbs

Question 8

The assembly area for substation structures should be planned so that a digger derrick can lift each section in the sequence it will set up.

Answer 8

True

Question 9

To determine the Working Load Limit (WLL) of rigging components, the ? is divided by the safety factor.

Answer 9

breaking strength

Question 10

When the nuts are installed, the bolts should be long enough so that at least ? thread(s) is/are seen protruding through the nut.

Answer 10

2

Question 11

As a substation structure is placed, the nuts are torqued to their required values before all bolts are set in place to prevent it from slipping.

Answer 11

False

Question 12

A synthetic web sling has a catalog breaking strength of five tons. Using the typical safety factor for synthetic web slings, determine the WLL.

Answer 12

2000 lbs

Question 13

In order to maintain a safe distance from a section being hoisted, tag lines should be used to control the section.

Answer 13

True

Question 14

Sling angle is the angle ? .

Answer 14

a sling leg makes with an imaginary horizontal line

Question 15

When two sling legs are used in a lift and the sling angle is ? , the tension on each sling leg is equal to the weight of the load.

Answer 15

30°

Question 16

A structural beam with a 2,000-pound mass is being lifted using two slings with a 60° sling angle. The tension on each sling leg is ? .

Answer 16

1,154 lbs

Question 17

A structural beam with a 2,000-pound mass is being lifted using two slings at a 45° angle. The tension on each sling leg will be ? .

Answer 17

1,414 lbs

Question 18

When rigging a shackle on a hook, to avoid the shackle sliding to one side of the pin and loading one leg, ? .

Answer 18

pack the pin with washers to center the shackle

Question 19

An alloy steel chain has a minimum breaking strength of 24,000 pounds. With a safety factor of ? , the working load limit is three tons.

Answer 19

4

Question 20

Because of high tensions, sling angles of ? or less are to be avoided.

Answer 20

30°

Question 21

When lifting an object with eyebolts attached, the loading should be applied in the plane of the eye so that the bolts do not bend sideways.

Answer 21

true

Question 22

A winch cable can come off and drop the load being lifted if ? or more wraps are not left on the drum.

Answer 22

2