Keel of the ship is the bottom most plate of the ship laid along the entire length of the ship. Commonly referred to as the ship’s backbone. During construction of the ship this is the first thing that is placed on the blocks. Because of this, laying the keel is considered to be the time when construction of the ship begins
There are 3 type of keels
> Flat Keel
> Bar Keel
> Duct Keel
Flat Keel
> It’s a modern type of keel and used in all types of sea going vessels.
> It is a solid plate which is supported by frames running around the vessel
> Flat plate keel may be fitted with the single bottom hull or with the double bottom hull
> It is thicker than the adjoining plates and must be of full uniform thickness for 3/5th length amidship.
Bar Keel
> This is the first type of keel which has been used since the first iron built ship. But it doesn’t provide sufficient strength for big vessels.
> A bar is placed in the center of the keel called a bar keel.
> The either side of the hull attached to the bar keel is called Garboard strake
> Depth of the bar is generally 3 to 6 times its width.
> These types of keels are incorporated in ferries or boats that are vulnerable to grounding.
Duct Keel
> This is also termed as Box keel because it allows pipes and other services throughout the keel length.
> This is fitted from the forward of the engine room bulkhead to the aft of the collision bulkhead.
> Duct keel is provided in double bottom hull ships and consists of solid plates welded into a box shape, forming an internal watertight passage running along the length of the ship
> Usually accessed a by a watertight manhole at the for’d end of machinery space
