Machining large marine bearing.

Zebra13 said:
Jackie,

With some of the lengths and diameters you deal with, it would seem that a single cutting pass in a lathe could take hours. True?

If so, what do you think your longest pass time-wise was?

Justin
Click to expand...

Yes it does. For a typical 9 inch diameter 28 ft shaft, with Stainless Steel Submerged Arc welded on all of the critical areas, you are looking at a final cost of around $34,000. 1/3 of that is material.

You start with 1022 hot rolled stock, straighten it and fully machine it down to the shape of the shaft. All areas that will have Stainless Steel weld overlay will be machine 3/8 under the finished sizes. The shaft is then sent to the submerged arc welder and welded. You then re-straighten where needed, and finish machine, including both tapers, and all bearing journals.

We then cut the keyseats in the prop and coupling end, and drill the coupling retainer plate holes. The shaft is then final straightened, and the coupling installed on the coupling end while shaft is in the lathe. That way we can insure that the coupling runs dead true as installed on the shaft.
We then coat all of the non Stainless Steel surfaces exposed to the water with epoxie resin fiberglass to protect against corrosion.

Yes on a shaft this long, it can take 8 to 10 hours to take the initial roughing cuts, which are usually around 3/16 to the side.

These are 9 inch shafts pretty close to being finished. The shiny surfaces are all 316L Stainless Steel weld. The other picture is raw bar stock that we start with.

http://benchrest.com/attachment.php?attachmentid=18174&stc=1&d=1470783637
http://benchrest.com/attachment.php?attachmentid=18175&stc=1&d=1470783924
 

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jackie schmidt said:
Many of you know that for the "snubber" on my tuners, I often is a small 1 1/8 shaft diameter rubber marine bearing that has a brass shell.

Here is a big brother version of the same type of bearing, for a 12 inch diameter shaft.


http://benchrest.com/attachment.php?attachmentid=18119&stc=1&d=1470668975

http://benchrest.com/attachment.php?attachmentid=18120&stc=1&d=1470670569
Click to expand...

Is this a Cutless bearing for a strut of a very very big ship?
I thought my Cutless bearing was big: my shaft of our boat was 2 inch shaft
 

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I am as well totally amazed! One of the finest examples of an American's ingenuity at a time when most think it has long been lost. Jackie's shop is the American dream being utilized to its fullest potential and a perfect example of what still makes this country great. I have been soaking all of this in as he also mentions what they have designed and built to fit there useful needs and the tremendous amount of common sense thus the creativity it takes and a trait most young folks sadly now seem to be lacking.

Jackie I really do thank you for taking the time to share, it has and still is one of most rewarding adventures I have been on for quite some time.

Yours Sincerely
John Louis
 
Bearings

Jackie, I'm pretty sure some of the ships or old diesel subs that came into the shipyard had lignum vitae bearings. I was told that the wood was so heavy it would sink.
The Navy pulled a couple of diesel subs out of moth balls for overhaul as they were being given to Turkey or Greece. Very tight quarters made it difficult to remove or install almost anything. You could spend eight hours breaking bolts loose with a slugging wrench, in the most uncomfortable position possible. There were only eight of us on swing shift and we had a variety of work assignments so when you came in you were not always sure what you would be doing. The only machine I didn't like was the turret lathe. Set ups were okay but after that it was repetition. My favorite was the grinding room. The tolerances were usually plus or minus .0001. The machines were capable of that so all you had to do was pay attention.
I worked there five plus years before the shipyard closed. I left the trade and went on to other things. I still have my Kennedy box and roll around with all my tools (Starret, Brown and Sharpe, etc.) which some I used putting motors together. I have a small shop at my house with a lathe that has a milling attachment and a nice drill press. I made odd or small parts for some of my cars or odds and ends for other people.
I really appreciate your machine shop threads.
Mort
 
dmort said:
Jackie, I'm pretty sure some of the ships or old diesel subs that came into the shipyard had lignum vitae bearings. I was told that the wood was so heavy it would sink.
The Navy pulled a couple of diesel subs out of moth balls for overhaul as they were being given to Turkey or Greece. Very tight quarters made it difficult to remove or install almost anything. You could spend eight hours breaking bolts loose with a slugging wrench, in the most uncomfortable position possible. There were only eight of us on swing shift and we had a variety of work assignments so when you came in you were not always sure what you would be doing. The only machine I didn't like was the turret lathe. Set ups were okay but after that it was repetition. My favorite was the grinding room. The tolerances were usually plus or minus .0001. The machines were capable of that so all you had to do was pay attention.
I worked there five plus years before the shipyard closed. I left the trade and went on to other things. I still have my Kennedy box and roll around with all my tools (Starret, Brown and Sharpe, etc.) which some I used putting motors together. I have a small shop at my house with a lathe that has a milling attachment and a nice drill press. I made odd or small parts for some of my cars or odds and ends for other people.
I really appreciate your machine shop threads.
Mort
Click to expand...

Lignum Vitae was used quite extensively in ships and vessels of all sizes. You are correct, it is quite heavy, and dense. But the biggest factor it had going for it was it's natural oil content. A properly fitted set of Lignum Vitae bearings were just about good for the life of the vessel.

One reason the Navy preferred water lubricated bearing over oil lubricated "white metal", ( Babbitt), was simplicity, and also with oil lubricated, a hit that compromised the oiling system could render the vessel immobile.

I actually have machined Lignum Vitae. It usually was machined into "staves", and these were wedge fitted into the stern tube, and then the ID align bored to the correct size.

Phenolics, ( Micarta) is one of the first substitutes for Lignum Vitae, then came the rubber compounds, and now a whole myriad of different materials.

The best by far, in my opinion, is the Thordon "River Tough". Run in conjunction with a Nickel Chromium Boron Liner, you can expect years of service.
Here is a pic of a River Tough Thordon Shaft Bearing as we get them, ID finished bored, OD to be machined by us to fit the vessel.
http://benchrest.com/attachment.php?attachmentid=18181&stc=1&d=1470860301

The downside......cost. The initial bearing cost quite a bit more than a conventional Cutless Bearing, and when using Thordon, you have to have a NIckel Chromium Boron Liner on the shaft in way of the bearings. This adds to the cost of the shaft substantially.
 

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So Sorry....

You missed out on a higher formal education. You could of avoided that boring job and hobbies with a wonderful Liberal Arts degree. :p

virg
 
Thanks for the pictures Jackie.
I worked at Continental Maritime of San Diego for 7 yrs. Then Moved to Pac-Ord which was owned by SPD Technologies. With them for 7 yrs.
SPD used to be ITE Gould of Philadelphia.
Yep. Electrician. At SPD I worked on 688 boats(and USS Virginia) and Aircraft Carriers.....When I moved back to the Detroit area. I sat down and counted the ships I had worked on or their Circuit Breakers/switchgear....I stopped at 99 ships....
Sorta miss the shipyards.......
 
Wilbur said:
Jackie...what do you mean by "submerged" ?
Click to expand...

Submerged Arc is a welding process where the wire is bare, but is continually and completely covered by a powdered flux. You do not have to wear a hood, as you cannot eye the arc or the puddle.

The man simply rakes the slag line off as the shaft turns. The welding head automatically indexes 1/2 the with of the weld bead every revolution.

If you look close at that picture, you can see the slag line forming behind the nozzle where the wire feeds down.

Up at the top you can see the big wire spool. We hang 50 pound spools at a time. The hopper just below that is what holds the powdered flux.
 
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Jackie is the bulk of your work from normal wear cycles, lack of proper maintenance or damage from the the unknowns hidden under the water.
I can also see an under laying mental pressure / emergency services to get a boat back in service as quickly as possible. Is this generally the case often times more than it is not.

JLouis
 
Louis.J said:
Jackie is the bulk of your work from normal wear cycles, lack of proper maintenance or damage from the the unknowns hidden under the water.
I can also see an under laying mental pressure / emergency services to get a boat back in service as quickly as possible. Is this generally the case often times more than it is not.

JLouis
Click to expand...

Normal wear cycles and damage from unknowns account for most drydockings.

Most of our big customers have dedicated maintenance schedules, varying between 28 and 36 months, if possible, for major drydockings. Inland tugboats, that being those that run the Intracoastal Canal and river tributaries, are some of the most abused equipment in Industry. It is amazing how banged up and just plain wore out these vessels get under "normal" service.
 
Jackie,

Why do you weld stainless on to the 1022 as opposed to using solid stainless? Cost? Metallurgical properties?

Justin
 
Zebra13 said:
Jackie,

Why do you weld stainless on to the 1022 as opposed to using solid stainless? Cost? Metallurgical properties?

Justin
Click to expand...

Cost is the big factor.

Anything under 5 inch diameter, it is cost affective to use solid stainless. There is stainless steel shafting specifically designed for the pleasure boat industry, yachts, smaller fishing trawlers and the like. The common industry name for it is "Aquamet Boat Shafting". It is basically 17-4 PH at a H1150 heat treat, ground and polished.

When you get over 5inch diameter, the cost gets prohibitive.

Also, the corrosion resistance of the Aquamet is very suspect in a closed stern tube, especially in boats that run the brackish water of the IntraCoastal Waterway. Crevis Corrosion Cracks are the big killer.

Our premium shaft starts with a mild steel core, stainless steel overlay in all circle areas, Nickel chrome Boron, (NCB), liners in way of the bearings, and epoxie fiberglass coating to protect all exposed surfaces.

The 6 top shafts on this storage rack are examples of these.
http://benchrest.com/attachment.php?attachmentid=18192&stc=1&d=1471021054
 

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zippy06 said:
Thanks for the pictures Jackie.
I worked at Continental Maritime of San Diego for 7 yrs. Then Moved to Pac-Ord which was owned by SPD Technologies. With them for 7 yrs.
SPD used to be ITE Gould of Philadelphia.
Yep. Electrician. At SPD I worked on 688 boats(and USS Virginia) and Aircraft Carriers.....When I moved back to the Detroit area. I sat down and counted the ships I had worked on or their Circuit Breakers/switchgear....I stopped at 99 ships....
Sorta miss the shipyards.......
Click to expand...

I also worked for a Pac-Ord or Pacific Ordnance for two years. They had a small shop in San Francisco and worked out of one of private yards. Most of the work was in electronics and hydraulics for small gun mounts. Allot of the work came from the small picket ships which were in decline because of the improvements in radar.
 
dmort said:
I also worked for a Pac-Ord or Pacific Ordnance for two years. They had a small shop in San Francisco and worked out of one of private yards. Most of the work was in electronics and hydraulics for small gun mounts. Allot of the work came from the small picket ships which were in decline because of the improvements in radar.
Click to expand...

I had heard that Pac-Ord had shops in all major ports. For gun repairs in the 50's-70's.
In the 80's-90's they specialized in custom "Wave Guide". I helped on a few ships.... There was a series of ships made in Miss. All 4 came to SD. And all 4 had some of their wave guide ripped out and made new. By order of SupShips. This was after testing. None were good enough. These were all brand new ships......
It's amazing what the Navy does to a new ship. On one LHA, they lined up 20 big dumpsters. Every day they were emptied. Everyday the crew filled them up. All new junk. The crews can redesign a ship how they want it. Not how it was built.
There are more horror stories.
 
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