Shipyard stories

zippy06 said:
Nice pictures..............
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I have been taking about fitting Propellers in our Shop. We are fitting a new set on new 8 inch shafts we built, going in a new 2500 HP push boat. Here is a video I took this morning of my men installing a Prop and removing it to take an impression.


https://www.youtube.com/watch?v=hPbI80ED_ys

As you can see, we have built special equipment specifically to perform this operation, and the men have been trained by us and are quite professional. We can put the Prop on, make it up with 20 tons of pressure on the taper, and remove it in less than 3 minutes.

As you can see, the impression shows the Prop needs a little touch up fitting to "spread the blue", so to speak and make it perfect.
 
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Jackie is it the taper in the bore of the prop that needs to be massaged or that of the shaft. The way I understood it it is the bore of the prop and is it quite typical for it to always require some additional work.

Thanks for the Video!
JLouis
 
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Louis.J said:
Jackie is it the taper in the bore of the prop that needs to be massaged or that of the shaft. The way I understood it it is the bore of the prop and is it quite typical for it to always require some additional work.

Thanks for the Video!
JLouis
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In the vast majority of the cases, it is the prop that needs to be fit to the shaft.

While I can't speak for other shops, we keep out tapers extremely close to the correct size and the correct taper per foot.

Prop bores can get distorted in several ways. Over heating and getting the crap beat out of them by Shipyards is a big culprit. But the biggest reason for bore warpage is the reworking of the blades. If blades get damaged in service, get knock out of pitch, the Wheel Shops literally heat the blades and twist them back into the correct shape and position. This movement of metal transfers all the way through the hub. The recourse is to refit the bore to a standard shaft after all of the repair is performed.

We often get shafts in from other shops that are not correct. Incorrect taper per foot is the biggest culprit. You never want to fit a prop to a shaft that is out of tolerance. It is best to correct the shaft first. Keep in mind, companies may have several vessels that use the same props. If you fit the prop to a bad shaft, then next time, if it goes on a new shaft, it will be really messed up.

This kind of work is very labor intensive. But, it's something that has to be done. That is why we have taken the time to build and acquire the proper equipment to perform the task as efficiently as possible.
 
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Prop Fitting

Jackie

Your shop really has the fitting process down.
How did you do this before you came up with the method your currently using?

Mort
 
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Wow! That was real PRO......
That ping was real nice......!
Nice video. How much were the actors....????? That is one smooth operation....And a very clean shop.....
Tell your guys thanks...Jackie.....
 
We have been doing this for years, and through the years have refined the process. Most of the refinement has centered around installing and removing the Prop with as much precision as possible in order to get an accurate impression, void of any "false readings".
Time is always of the essence. It takes less than 3 minutes to install and remove the prop each time. And depending on how bad the bore of the prop is, you may put it on and take it off dozens of times.
Using the 20 ton hollow ram jack for installation and removal is something that we came up with. We have made tooling to fit any prop thread, and studs to fit any prop.

Most shops look at Propeller fitting as a secondary thing. We don't. To us it is just as necessary to the entire scope of our business as any other operation that is needed in order to get a vessel back in service.
 
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Jackie I would tend to think if done properly it would also stay in service longer and thus be a big cost savings for your customers. I like to spend sometime watching Keith Fenner's You Tube Video's and he has shown several issues misc. brought about by inproper Prop installations. His heat straighting of Marine shafts has also intrigued me quite a bit. All though his work is geared towards smaller marine vessels the importance of doing it right I think would be the same with the goal being to save his customers money. Or one could possibly just put it as the highest quality of work as your shop turns out being a good long term investment.

JLouis
 
jackie schmidt said:
We have been doing this for years, and through the years have refined the process. Most of the refinement has centered around installing and removing the Prop with as much precision as possible in order to get an accurate impression, void of any "false readings".
Time is always of the essence. It takes less than 3 minutes to install and remove the prop each time. And depending on how bad the bore of the prop is, you may put it on and take it off dozens of times.
Using the 20 ton hollow ram jack for installation and removal is something that we came up with. We have made tooling to fit any prop thread, and studs to fit any prop.

Most shops look at Propeller fitting as a secondary thing. We don't. To us it is just as necessary to the entire scope of our business as any other operation that is needed in order to get a vessel back in service.
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You DA Man and your shop. I can see why you are always busy...I used to work at a Shipyard that prided itself in being the Customer's Friend......
 
Chippers

This was a trade you didn't want to be near because they made so much noise. You didn't a want job in the same space or compartment they were working in.

These guys used pneumatic chisels to remove old welding or whatever. I was never curious enough to watch.

One time a Pipe Fitter, another guy and myself were in the process of removing a separator when a Chipper started working in an adjacent bulkhead. The noise was deafening.

The other machinist who had been through this before, took his slugging hammer and started beating on our side of the bulkhead. Now the noise was over the top.

The Pipe Fitter with cupped ears was trying to say something. I'm sure it wasn't nice or maybe he was just threatening to leave...I don't remember.

Anyway the noise stopped. My stressed out partner took the credit but maybe the Chipper quit on his own. Don't really know.

PS: the separator spins at a high RPM and in doing so separates oil from the boiler feed water.

Mort
 
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Some folks call a separator a centrifuge....separator says it best in the case of oil and water. I've spent many an hour trying to stay awake while running one of those things.
 
At that nuclear plant where I used to work. I don't understand the why part of the question.....
 
Wilbur

It just goes to show you how little I know about a nuclear plant.

I assumed you had the watch in the engineering space on a ship.

I also assumed you may have been tired from having to much fun ashore....therefore the why.....Just poking a little fun.

I will assume no more.

Mort
 
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A nuclear plant has that turbine that turns the generator. The turbine oil is expensive stuff and there was a time where the centrifuge was the better deal rather than buy new oil. I don't know the exact details but in the end they quit using the centrifuge and just bought new oil. That freakin' centrifuge was a very touchy device and it would overflow into the floor at times causing a difficult clean up job. That little bit said, I was glad they quit using that thing to clean oil!!!

Now that I know why you asked why....the hum of that thing, in that little room, would put you straight to sleep...regardless. When we ran it, the roaming "turbine building" operator went there every now and then to wake the guy up. Not to see if the guy was awake but to wake him up. One out of five times, the guy was asleep and oil running to the floor drain.
 
Wilbur

Good info and a good story. Sitting here with my coffee and a grin on my face.
 
Laggers

Laggers insulate pipe, and on steam powered ships there is a lot of pipe. I couldn't even guess how much, even on the smaller ships.

With the insulation, I was told, temperatures could reach well over 110 degrees....ouch! So the insulation is a necessity for even a normal operation.

What eventually became a real issue was the asbestos used in the insulation.

We were told not to breathe this stuff if you could avoid it. Normally it wasn't a problem until it was cut into and exposed to repair pipes or machinery, as it was always covered with a heavy coat of white paint.

I never saw the lagging/insulation installed or being removed. So I can't say how it was done. I do know the removal left a powder like residue that was impossible to get rid of. This isn't like your kitchen floor, there a so many irregular surfaces you just can't do it.

If you worked in a shipyard trade you are going to be exposed....so how much is too much? What trades suffered more?

I think we have all seen the ads on TV where the lawyers are looking to get their share of the settlement. If you think it is really about you ....you need to start closing the door on your microwave.

I was exposed to asbestos and I have COPD....but that has more to do with the Luckies I kept in my roll around than anything else.

Mort
 
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U.S.S. Guitarro SSN-665

We used to sit in an empty day foreman's office to eat lunch on the night shift. There were enough chairs in there for our small group to sit.

There was always talk, or BS about guns, hunting, and fishing. Some of the stories were pretty good. One of the stories that went around was about our boys across the bay [Mare Island] had sunk a sub at the pier.

I had mentioned this story on another thread, but I didn't really know if it was true....There was a little animosity here because Mare Island was building Nuclear Subs for the Navy and were supposedly buried in $$$$. If they needed new machinery and tooling they got it. Meanwhile we had our jumping and shaking Hydrotel that we were sure would someday would set the floor on fire.

Another local joke was that we still had the tooling for Noah's Ark. It was there somewhere...cataloged, tagged and with 300 pages of documentation.

Anyway I did a little research and the story told at lunchtime in 1969 was true.

They sunk the sub.

After reading the official report, it reminded me of a poem about the Minnesota CC crews back in the Depression. "One a comin' one a goin' one a sittin' and one a mowin'.

Please feel free to substitute words where appropriate.

Mort
 
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dmort said:
Laggers insulate pipe, and on steam powered ships there is a lot of pipe. I couldn't even guess how much, even on the smaller ships.

With the insulation, I was told, temperatures could reach well over 110 degrees....ouch! So the insulation is a necessity for even a normal operation.

What eventually became a real issue was the asbestos used in the insulation.

We were told not to breathe this stuff if you could avoid it. Normally it wasn't a problem until it was cut into and exposed to repair pipes or machinery, as it was always covered with a heavy coat of white paint.

I never saw the lagging/insulation installed or being removed. So I can't say how it was done. I do know the removal left a powder like residue that was impossible to get rid of. This isn't like your kitchen floor, there a so many irregular surfaces you just can't do it.

If you worked in a shipyard trade you are going to be exposed....so how much is too much? What trades suffered more?

I think we have all seen the ads on TV where the lawyers are looking to get their share of the settlement. If you think it is really about you ....you need to start closing the door on your microwave.

I was exposed to asbestos and I have COPD....but that has more to do with the Luckies I kept in my roll around than anything else.

Mort
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My Dad worked in Shipyards just before WW-2 and after the War. He was exposed to a lot of asbestos dust, both in new construction and the dismantling of ships.

He also smoked every day of his adult life.

He was diagnosed with lung cancer at age 59. They "treated" him for well over a year, but then Mesotheleoma cropped up, and he died a month or so later.

I am now over 9 years older than he was when he died. In my younger years, we worked with a asbestos compound called Transite. It was cement and asbestos mixed, from which we machined insulator blocks for a electric furnace smelting plant.

The word is that since it was mixed with cement, the asbestos fibers were not able to collect in ones lungs like asbestos fibers.

I have been checked, and my lungs look clean. But I do worry.
 
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