Bu basic CH7 Flashcards
1
Q
- What are the two most commonly used natural fiber ropes? (Page 7-3)
A
manila and sisal
2
Q
- Sisal fiber is only about what percent as strong as manila fiber? (Page 7-3)
A
80%
3
Q
- How many times stronger is nylon compared to manila? (Page 7-3)
A
three
4
Q
- The three types of fiber line lays include hawser-laid, shroud-laid, and what other type? (Page 7-4)
A
cable laid
5
Q
- What type of fiber line lay is more pliable and stronger than hawser-laid line but has a strong tendency toward kinking? (Page 7-4)
A
shroud laid line
6
Q
- Line that is how many inches or less in circumference is called small stuff? (Page 7-5)
A
1 3/4 inches
7
Q
- What size is about the largest manila carried in stock? (Page 7-5)
A
12 inches
8
Q
- To avoid overloading, you must know the strength of the line with which you are working which involves what three factors? (Page 7-5)
A
breaking strength safe working load (SWL) and safety factors
9
Q
- What property of a line is the ratio between the breaking strength and the safe working load? (Page 7-7)
A
safety factor
10
Q
- Wire rope consists of three parts; Wires, strands, and what else? (Page 7-8)
A
core
11
Q
- A wire strand core not only resists heat more than a fiber core, but also adds about what percent to the strength of the rope? (Page 7-9)
A
15
12
Q
- What method of making wire rope is when strands or wires are shaped to conform to the curvature of the finished rope before laying up? (Page 7-9)
A
performed
13
Q
- The main types of wire rope used by the Navy consist of 6, 7, 12, 19, 24, or how many wires in each strand? (Page 7-9)
A
37
14
Q
- What is the tensile strength of mild plow steel rope? (Page 7-9)
A
200,000-220,000 psi
15
Q
- Each square inch of improved plow steel can withstand a strain of 240,000 to what psi? (Page 7-9)
A
260,000
16
Q
- To ensure an accurate measurement of the diameter of a wire rope, always measure at three places, at least how many feet apart? (Page 7-9)
A
5
17
Q
- When what percent of the total number of wires in the rope have breaks within the length of one lay of the rope, the wire rope is unsafe? (Page 7-17)
A
4%
18
Q
- Rope with a diameter reduced to less than what percent of its original diameter should be removed from service? (Page 7-17)
A
75%
19
Q
- What is the attachment used most often to attach dead ends of wire ropes to pad eyes or like fittings on earthmoving rigs? (Page 7-17)
A
wedge socket
20
Q
- By what percent does the wedge socket reduce the strength of wire rope? (Page 7-17)
A
30%
21
Q
- Clipped eyes with thimbles hold approximately what percent of the wire rope strength? (Page 7-19)
A
80%
22
Q
- What is an assembly of blocks and lines used to gain a mechanical advantage in lifting and pulling?
A
tackle
23
Q
- What is a lie, either a fiber line or a wire rope, reeved through a pair of blocks to form a tackle? (Page
A
fall
24
Q
- The sheave diameter should be about how many tmes the diameter of the wire? (Page 7-22)
A
20
25
Q
- What are ordinarily used where it is necessary to change the direction of the pull on a line? (Page 7-23)
A
snatch blocks
26
Q
- What property of a tackle is the term applied to the relationship between the load being lifted and the power required to lift it? (Page 7-24)
A
mechanical advantage
27
Q
- What is a single sheave movable block that is free to move along the line on which it is reeved? (Page
A
runner
28
Q
- What is a technique often used to close the open section of a hook to keep slings, straps, and so on, from slipping off the hook? (Page 7-31)
A
mousing
29
Q
- What are the two types of scaffolding in use today? (Page 7-40)
A
wood and prefabricated
30
Q
- The poles on a job-built pole scaffold should not exceed how many feet in height? (Page 7-41)
A
60
31
Q
- A platform plank must never be less than how many inches thick? (Page 7-42)
A
two
32
Q
- Light-duty scaffolding must be able to support how many pounds per square foot loads? (Page 7-42)
A
25
33
Q
- Medium duty scaffolding must be able to support how many pounds per square foot loads? (Page 7-42)
A
50
