Flashcards

Lifting and Rigging

Vincent Bergeron Inglês 33 flashcards

Flashcards do conjunto (33)

1What is the SWL?Safe Working Load
2What is a rule of thumb for calculating the SWL of wire rope?3/8" thick rope = 2000lbs (1 ton)
every 1/8" larger adds 2000lbs (1ton)
3Safe Work Load in Tons for Wire Rope with a safety factor of 5SWL = D² x 8
4How much can a knot reduce the breaking strength of fibre rope by?50%
5How much can correctly attached cable clips reduce the breaking strength of wire rope?20%
6What should you do with sharp corners on a load and why?Have padding or soft corners in place to reduce abrasion on the rope
7What does a basket web sling look like and what is it used for?It has metal triangles of equal size at each end of the webbing
8What does a choker web sling look like and what is it used for?It has a larger triangle containing a slot at one end and a smaller triangle at the other end
9What is a metal mesh sling and what is it used for?A sling made of metal mesh.
used when a load is too abrasive or hot for synthetic webbing.
10What is the formula for the SWL of a basket hitch? Give some examples!SWL x H/L x 2
SWL of a sling is rated 2000
H= 3ft
L= 5ft
SWL=2000lbs x 3/5 x 2 = 2400lbs
11What is the formula for the SWL of a two-leg bridle hitch? How does it differ from a basket hitch?SWL x H/L x 2
It uses the same formula as the Basket Hitch but use the shortest length hitch when doing the calculation.
12If a choker hitch angle is over 45 degrees, what formula do you use to calculate the SWL? Give an example!SWL x 3/4
SWL=2000 x 0.75 = 1500lbs
13If the choker angle is 45 degrees or LESS, what is the formula to calculate the SWL? Give an example!SWL x H/L
SWL of a sling is rated 2000
H= 3ft
L= 5ft
SWL=2000 x 3/5 = 1200lbs
14If you use chokers in pairs, horizontally, how do you calculate the SWL of these kind of sling configurations?SWL x A/B x H/L x 2
15What is a double basket hitch and how do you calculate its SWL?Two Basket Hitches used to lift a part.
SWL x H/L x 4
16What is the approximate weight of a cubic foot of steel?500Lbs
17What is the approximate weight of a cubic foot of wood?35Lbs
18What is the mechanical advantage of the block ?The ratio of Load to Effort.
Used to lift heavy loads using a small amount of effort.
19What are the essential parts of any block?Shell
Sheaves
Center pin
Straps
Becket
20What do each of the parts of a block do?Shell: Provides protection for Sheave
Sheaves: transmit the load imposed by the rope to the center pin.
21What are the sheaves normally made of on fibre rope blocks?Cast iron
22Why are fibre rope sheaves NOT used with (rope-wise) and why?Rapid rope damage will result
23what is a double basket hitch? Why is it used?Loads that require support from underneath are lifted with two basket hitches.
24What is a single vertical hitch?A single leg of sling material with a hook and an eye at each end
25What is a Bridle hitch?Two three or more legs can be used together to form a bridle hitch
26What is a single basket hitch?A single length of sling material passed through a load
27What is a double wrap basket?The sling is wrapped completely around the load
28What is a single choker hitch?A single sling is hooked back to itself just above the load
29What is a double choker hitch?Two single chokers used to lift a load that require level lifting
30What is a Double-wrap choker hitch?The sling is wrapped completely around the load and hooked back to itself just above the load
31What is an endless sling?A sling that is joined at both ends to create a loop.
32What is a synthetic web sling? What are its advantages and disadvantages?Slings made of synthetic material.
They are soft, which protects the loads they are lifting from being scratched by the sling.
Heat and friction damage them.
33What are the differences between the endless, standard eye, and twisted eye synthetic web slings?Endless: a sling connected to itself, forming a loop.
Standard eye: A sling with a loop at each end.
Twisted eye: A sling with a loop at each end that is twisted.