Question 1. What is the construction of the topping lift of a 5 or 10 ton derrick?

Answer: Topping lifts are usually a 24 mm EFSWR of 6 36 w.p.s.

Question 2. What is the safe working angle, between the two runners when derricks are rigged in union purchase rig?

Answer: Runner wires have a safe working angle of 90 but may carry out occasional lifts up to 120 .

Question 3. A 5 ton SWL derrick is marked at the heel with a 'U' = 1.6. What does this signify?

Answer: 'U' represents the union purchase, safe working load, in this case U = 1.6 ton.

Question 4. What is the difference between a 'hounds band' and a 'spider band'?

Answer: A hounds band is the lugged band found around a mast to support the shrouds and the supporting stays. A spider band is found around the head of a derrick, to secure the guys, topping lift and lifting purchase.

Question 5. What marking would you expect to find on the binding of a metal block?

Answer: The safe working load and the certificate number.

Question 6. What is the difference between a 'head block' and a 'heel block'?

Answer: Very little difference other than the head fitting on the head block is an oval becket, while the 'heel block' will be fitted with a 'duck bill' fitting to accommodate the gooseneck arrangement.