Maritime quandry

[samuttodd]

I live near the river and watch the ships come and go each day from my window.

 

Most of the vessels are dredges.

I've noticed that some of the dredge vessels are going out loaded to the plumbline,

and some of them are coming in loaded to the plumbline.

 

I'm only about 1000 m from the mouth of the river.

 

I would think that the dredge should load up upriver,

go off in the salt water and dump it's load,

and then go back empty to pick up more dirt  from the river bottom...

 

Apparently loaded dredge ships are going up River from the mouth. Why would this be?

 

are they coming back full of water to act as ballast?

 

 

[YT3k72Em]

Are you sure they are not barges?

[greg67]

They might be using ballast water in order to maintain desired "trim". Trim is the difference between forward and after draft of the ship. Having desired trim will increase ship's steerage while going up river... In other words, having desired trim, will make ship more maneuverable in the water...

[samuttodd]

17 hours ago, greg67 said:

They might be using ballast water in order to maintain desired "trim". Trim is the difference between forward and after draft of the ship. Having desired trim will increase ship's steerage while going up river... In other words, having desired trim, will make ship more maneuverable in the water...

That was what I was thinking.   They are for sure dredges,  we've got a bunch on the lower river..  We've got barges too.