Duck Tails

[gelfy666]

me and the wife were just wondering why some ships have Duck Tails and why?

[Aquahound]

It lengthens the waterline and basically decreases resistance. It decreases energy consumption and in some cases, improves stability.

 

Lots of ships have them nowadays. They are even being added to older ships.

 

On this older ship for example, Rhapsody of the Seas, it was recently added.

 

[rwr235]

Your question caused me curiosity as well...here a couple brief synopses I quickly found:

 

***Ducktail An extension to ship’s stern. On older ships the diminished stability

can be regained by adding a ducktail. Ducktail is also used on

newbuildings; there the primary purpose is often to reduce the power

consumption for propulsion.

***A ducktail is basically a lengthening of the aft ship. It is usually 3-6 meter long. The basic idea is to lengthen the effective waterline and make the wetted transom smaller. This has a positive effect on the resistance of the ship. In some cases the best results are achieved when a ducktail is used together with an interceptor.

 

4-10% lower propulsion power demand. Corresponding improvement of 3-7% in total energy consumption for a typical ferry.

 

Probably someone with more marine mechanical engineering expertise will come on and answer with more detail.

 

Sorry for some repetition...was typing as Aquahound posted similar :)

 

Woody

[gelfy666]

Thanks for replies, as I say we just wondered.

 

Having only ever been on Ventura we've never experienced one.

[NMLady]

I learned something new. I didn't even know that extension was called a duck tail, and I thought it was purely ornamental.

[CPT Trips]

Bootylicious? Ornamental and functional.