Rigging 1: Chapter 8 & 9 - Parted Blocks & Snatch Blocks - Possible Test Questions Flashcards
Nomenclature of a parted block:
- Hook (Carries the weight)
- Safety Latch (Secures the rope)
- Swivel (Connects the hook to the shell)
- Shell (Exterior of block)
- Sheaves (Allows the rope to travel)
- Center Pin (Secures the sheaves)
- Becket (Secures rope bight opposite from hook)
Parted blocks are most commonly used to:
- Sag conductors
- Set poles
- Hang pole line equipment
Where would you normally find the weight rating on a block?
- On the hook or shell
For slings, if a weight rating tag cannot be found, it is to be removed from service. Would the same action be applied to a block?
- Yes
In technical terms, what is it that a block provides?
- A mechanical advantage
The two main tensions involved with parted blocks:
- Haul Line
- Hook Strain
Why is Haul Line calculated?
- To verify that the working load limit of the rope is not exceeded. It is also calculated to determine that the working load limit (WLL) of the hoisting mechanism is not exceeded.
Why is Hook Strain calculated?
- To verify that the working load limit of the blocks is not exceeded
Parted blocks consist of two blocks:
- Standing block
- Running block
For every sheave a rope passes through, __% friction is added to the weight applied to the rope.
- 10
Haul Line Formula:
- 1.1^P x W / P
The greater mechanical advantage occurs:
- at two parts when the haul line tension is nearly cut in half
The friction overcomes the mechanical advantage after __ parts.
- 10
What happens after more than 10 parts are used?
- Haul line tension begins to rise
Increasing the number of parts supporting the load will:
- Decrease the tension on the haul line
