# Mooring Force & Winch Capacity calculation

Discussion in 'Boat Design' started by ociship, Dec 2, 2009.

1. Joined: Dec 2009
Posts: 11
Likes: 0, Points: 0, Legacy Rep: 10
Location: vietnam

### ocishipJunior Member

When calculation for 56K B/C
I have some inform. as below:
- L.B.P = 182.50M
- DEPTH = 18.30M
- DRAFT AT BALLAST DRAFT = 5.77M

I DON'T KNOW HOW CAN I CALCULATE SOME SHIP'S CONDITION Below:

- WIND PROFILE AREA AT BALLAST DRAFT = ?
- WETTED SURFACE AREA AT BALLAST DRAFT = ?
- WETTED PROFILE PROJECTED AREA = ?
- WIND SPEED DURING MOVING = ?
- WIND SPEED DURING MOORING = ?

Thank you very much.

2. Joined: Oct 2008
Posts: 92
Likes: 11, Points: 8, Legacy Rep: 15
Location: Jersey C.I

### VelsiaFloater

You cannot calculate accurately

wind profile @ ballast draft
wetted surface area @ ballast draft
Wetted profile projected area

Without having the plans for the ship.

This will help you with the wind speeds http://www.sailingusa.info/true_wind_calculator.htm but I don't understand your definition of "mooring"

Out of curiosity could you permit me to be nosey and ask for what reason you are asking this question?

3. Joined: Dec 2009
Posts: 11
Likes: 0, Points: 0, Legacy Rep: 10
Location: vietnam

### ocishipJunior Member

Mean "mooring" all ship is included "bollard, anchor, roller, winch...etc." to be used keeping ship or boat at harbour.

4. Joined: Apr 2005
Posts: 4,127
Likes: 148, Points: 0, Legacy Rep: 2043
Location: Ontario

### marshmatSenior Member

Your wind profile area and wetted profile projected area can be extracted from the drawings of the ship: just look at the profile view, take the total area above water, and then the total area below water. The wetted surface should be known from the main particulars table. These aren't particularly precise formulae, that you'd be using, more likely they're empirical approximations. Close enough plus a safety factor is the best you can likely hope for.

5. Joined: Dec 2009
Posts: 11
Likes: 0, Points: 0, Legacy Rep: 10
Location: vietnam

### ocishipJunior Member

Thank you for your help, and then finally you kindly tell me "take the total area above water and total below water" is mean plus including "Port side, Starboard side, forward and after area" or only Port side or starboard side?

Forum posts represent the experience, opinion, and view of individual users. Boat Design Net does not necessarily endorse nor share the view of each individual post.
When making potentially dangerous or financial decisions, always employ and consult appropriate professionals. Your circumstances or experience may be different.