SECURING DERRICKS AT SEA

General Objectives:

To describe means of securing derricks at sea.

Specific Objectives:

Specifically, this aims:

1. To be able to define a derrick.

2. To be able to enumerate different types and ways of securing derricks at sea.

3. To know the advantages and disadvantages of using derricks at sea.

REFERENCES/MATERIALS

• SEAMANSHIP TECHNIQUES (SHIPBOARD AND MARINE OPERATIONS) by DJ House, M.M
• Seamanship notes by Kemp & Young
• http://www.generalcargoship.com

DEFINITION

A basic type of derrick is controlled by lines (usually four of them) connected to the top of the mast, powered by some means such as man-hauling or motors, so that the pole can move in all four direction

a simple crane that is typically used for moving cargo onto or from a ship

composed of one tower, or guyed mast such as a pole

which is hinged freely at the bottom

SECURING DERRICKS AT SEA

TOPPING THE BOOM

Raising the boom above the deck to the desired height

CRADLING THE BOOM

SPOTTING THE BOOM

Lowering the boom to the boom support on deck and lashing or clamping the boom in place.

Secured alongside the boom by lashings.

On long ocean crossing, the gear is removed, inspected and overhauled and replaced when necessary.

The process of swinging the boom horizontally over the desired spot and securing.

Presented by:

Mdpn. Mark Luis S. Sedicol

Presented to :

2M Moises Teñosa

HOUSING THE BOOM

The process of securing a boom for sea, where the boom is hauled aloft close to the mast and secured. The gear maybe lashed to the boom or removed as in cradling.

SUMMARY

TEST/EVALUATION

DISADVANTAGES

ADVANTAGES

QUESTIONS AND ANSWERS

ASSIGNMENT

What are the other ways and means of securing derricks at sea?

Give at least one way or mean on how to secure derricks at sea and explain how it is being done.

A derrick is a simple crane used to transfer cargoes from or to the ship. There are four ways to secure derricks at sea namely; topping the boom, cradling the boom, housing the boom and spotting the boom. Each has different ways of securing the derrick. Furthermore, there are also some disadvantages of using derricks amidst its advantages.

1. What is a derrick? What is it for?

2. What are the different ways or means in securing derricks at sea?

3. In your opinion, what is the safest way of securing derricks at sea?

• Simplicity of component parts
• Ability to change rig to suit loading/discharging requirements
• Maintenance is minimal, provided that winches are good

• Deck is cluttered with guy ropes and preventers
• Operation usually requires two winch drivers and a hatch man.
• Time delays in changing derrick rig for different cargoes.