Slipway Winch

Here are some photos. Notice that large railways sometimes use chain for a hauling cable. The third shot of a 3 screw tug on the ways is a yard I worked in for many years.

 

Sorry! I am a junior about vessel operation. Can I ask some more simple questions? As follows:
1.How to guide the vessel over the ways car? Using tug boat? or drive in position by the vessel(Is it possible ,especially for large vessel)?
2.The arms and supports are adjusted by the divers?
Thanks for your reply.

 

Vessel is guided into place gently with ropes and small boats. Supports are usually arranged so no diver is required, as divers cost money.
This can either be pre-blocking to the plans of the vessel, or adjustable blocking or supports, usually operated with small hand winches and steel cable.
This all depends on the shape of vessel being hauled. Some are easy, some are difficult.
Google "marine railway" images and study closely.

 

Also, the safe design, build and operation of a large marine railway requires experience in the job and is no place for a beginner who knows very little about them.

 

Here is a short video of a working shipyard with 7 marine railways in southern Okinawa. Note the method of shoring KAISEI, a high-bilged and difficult to haul vessel.
http://www.youtube.com/watch?v=vMMGjaOOamo

 

Thanks a lot! and Have a good night!

 

Do you have the experience of using concrete tracks?
It's hardness and strength are smaller than steel, is it lasting long?
Thanks for reply!

 

You can break stuff and someone will get hurt...

 

Sorry! I am real a junior in the actual operation of vessel and associated facilities. And I hope that I could get some experienced information from this forum. Thanks for your stand.

 

Hi everybody, I have a task to develop on the calculations of a shipyard that uses a slipway system that is pulled by an electric winche. They ask me to calculate the current pulled capacity of that Winche in tons. Could someone help me with ideas to start the calculations?

 

You will need to know the following:

1. max weight to be moved
2. the declination of the slipway (max angle)
3. means of moving the weight... i.e. slipway...rails...trolley..etc

 

Ok, I have the following initial information:
1. max weight to be moved: This is what I need to calculate
2. the declination of the slipway (max angle): 3,5º
3. means of moving the weight... i.e. slipway...rails...trolley..etc: Slipway with known dimensions

Now, I have a question with the gears that help move the cables that drive the carriage. How is the required calculated?

 

The force "pull" required for your winch will be: force to overcome gravity + friction force

F = W sin(theta) + (mu).W cos(theta).

Theta = 3.5
mu = whatever kind of slipway you have = its coeff. of friction
W = weight of object

 

The OP needs to state the speed requirement. That will be one of the factors determining the necessary power. Also, there needs to be reserve power to get the ship moving.

 

There are indeed many issues that need to be taken into account.
Ive designed several such system in the past....but it all starts with what is the max weight one wishes to launch/recover. ..??!!