Align Boring The Struts And Stern Tube In A New Corps Of Engineers Push Boat

[Road_Clam]

Great pics thanks for sharing. I worked 22 years machining in the heavy hydraulics industry and when your boring the "big stuff" your worst enemy in mitigating harmonic vibrations .

 

[jackieschmidt]

Do you need to use a cooling liquid on the tools, or do you have to change them out after a cut or two?

The tools are 3/4 square High Speed Steel, I grind them and sharpen them myself after each cut. Pretty simple.

As for coolant, I just squirt some high sulphur cutting oil up in the hole.

 

[Road_Clam]

The tools are 3/4 square High Speed Steel, I grind them and sharpen them myself after each cut. Pretty simple.View attachment 1427024View attachment 1427025

With all the super high tech coated inserts theres still a place for old skool' custom ground HSS . Even on my small benchtop 11x29 lathe , in many circumstances i prefer HSS.

 

[Ksracer]

I miss working on the big/oddball shit.
What's the thrust bearing look like?

 

[tobnpr]

And I thought alignments on my lil' 40 footer were tough... wild stuff there, thanks for sharing.

 

[jackieschmidt]

I miss working on the big/oddball shit.
What's the thrust bearing look like?
View attachment 1427100View attachment 1427101View attachment 1427102

That top picture appears to be the out put coupling assy on a ship. It has been a while since I worked on something that large.

As for the thrust in these vessels, it is all contained in the reduction gear in the way of a large roller bearing.

Here is the model gear going in this boat.

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The engines will be Cat 3516’s, the props 84x60.

 

[Ksracer]

That top picture appears to be the out put coupling assy on a ship. It has been a while since I worked on something that large.

It's the coupling between two LP sections in a 360 megawatt steam turbine/generator train. It spins 3600rpm and makes roughly 450,000HP.

 

[brcman]

Yes a lot of that great music from Port Athur would include Janis Joplin

 

[ronsatspokane]

And I thought alignments on my lil' 40 footer were tough... wild stuff there, thanks for sharing.

My thoughts exactly. A little 2 or 2.5 inch shaft. I followed the link to those seals Jackie posted. One of them handles 11.8 to 39 inch diameter shafts. One of those shafts would weigh more than the largest boat I've ever owned.

 

[jackieschmidt]

Yes a lot of that great music from Port Athur would include Janis Joplin

Yep, this is my favorite.

A singer had to Stoned, Drunk, and Ugly to belt out this the way Janice Joplin did

 

[jackieschmidt]

It's the coupling between two LP sections in a 360 megawatt steam turbine/generator train. It spins 3600rpm and makes roughly 450,000HP.

I have worked on some big things but NOTHING approaching that.

 

[jackieschmidt]

With all the super high tech coated inserts theres still a place for old skool' custom ground HSS . Even on my small benchtop 11x29 lathe , in many circumstances i prefer HSS.

This particular operation is about the only thing we still use HSS on.

These bars work on the principle of low sped and relative high feed rates, typically .007 per Revolution.
Carbides tend to break.

Besides, HSS works great.

 

[Road_Clam]

This particular operation is about the only thing we still use HSS on.

These bars work on the principle of low sped and relative high feed rates, typically .007 per Revolution.
Carbides tend to break.

Besides, HSS works great.

Yest it does, and easily resharpened with just your basic grinding wheel or belt sander.

 

[tobnpr]

Nothing to do with the machining, but boater curiosity...
What type of seals are used for those shafts? Do they have some sort of monster-sized PSS dripless shaft seals- or entirely different technology?

 

[jackieschmidt]

Nothing to do with the machining, but boater curiosity...
What type of seals are used for those shafts? Do they have some sort of monster-sized PSS dripless shaft seals- or entirely different technology?

Most use the same principle as high pressure pump seals.

Two precision lapped Silicone Carbide or Ceramic faces sitting flat agains each other . They are held in compression by a flexible “bellows” that preloads the two faces together and is held in place by a clamp that turns with the shaft.

These seals are just about leak free.

They are also expensive. The two shaft seals for this vessel will probably cost around $30,000.