Big Dredge Boat Boring Job

[jackieschmidt]

Monday we will start setting up to align bore the shaft line for the big Cutter Head Shaft on this Dredge.

The shipyard will finish all of the welding in of the new bearing bosses this week end. The bearing bosses will be finished bored to 12.370 diameter. The last picture is of a fixture I made to align the wire with the large gearbox shaft.

The bearings will be water lubricated Duramx Cutless Bearings Pressed in.

Johnson Cutless (Cutlass) Water-Lubricated Rubber Bearings

Johnson Cutless, the original, true Cutlass bearing, only available from Duramax Marine. These rubber bearings have oil resistant nitrile polymer lining.

www.duramaxmarine.com

I will take some pictures as we are setting up. I will be using our 14 foot long 4 inch bar.

 

[D Coots]

How long is the cutterhead on the dredge Jackie? Can't make it out. Is it a chain ladder? What diameter is the suction pipe?

 

[tobnpr]

I'm guessing you don't use a hacksaw/chisels to split the old bearings to remove them like my lil' 1-1/2" ones...
Hydraulic press and puller?

 

[jackieschmidt]

Dave, the cutter head will be attached to he shaft that will be installed in these bearings. It’s a 10 inch shaft, so I figure maybe 5 feet in diameter.

The dredge is 180 foot long, named the Heriberto Cordova. I think the main pump engine is a 16-645 EMD. It’ all covered up, I am not sure if it is Roots Blown or Intercooled Turbo Charged.



here is a picture of the main suction located just aft and below of the cutter head mount.

 

[V35]

Thanks for posting, im always interested in stuff like this. I spent a lot of time align boring dirt moving equipment pin and bearing locations, but never have done anything marine related. I see this and think maybe I should have moved to the coast and got some of it.

 

[Retired shooter]

Thanks for posting. Very Interesting, however I am glad my out in the field welding days are over.

Some of the shop stuff may be coming to an end also.

Latter Guys

 

[jackieschmidt]

Thanks for posting, im always interested in stuff like this. I spent a lot of time align boring dirt moving equipment pin and bearing locations, but never have done anything marine related. I see this and think maybe I should have moved to the coast and got some of it.

Now days You can count the number of people who want to do this kind of work on one hand,….with two fingers cut off.

 

[Carl S]

Now days You can count the number of people who want to do this kind of work on one hand,….with two fingers cut off.

I would love it Jackie.

 

[boltfluter]

Interesting read on the bearings. So the bearing will be a press fit into the hole you are going to line bore. Just curious, what tolerances do you have to hold on the bore? Looking forward to the pics as you progress through the job.
Paul

 

[D Coots]

That bad boy would definitely move some material. Looks like 16 or 20" suction pipe??? I imagine the hydraulicly driven shaft you're working on turns the cutterhead basket at a slow rpm???

My sand dredge was about half that long and had 10" suction/10" discharge. Seems like the impeller was 32" diameter. We could go 50' deep with it to the bottom of the deposit where we hit limestone. Seems like 1,250 gallon per minute pump and would produce 325 tons of sand per hour. Powered by a 575hp Cummins.

 

[jackieschmidt]

Interesting read on the bearings. So the bearing will be a press fit into the hole you are going to line bore. Just curious, what tolerances do you have to hold on the bore? Looking forward to the pics as you progress through the job.
Paul

Normally, our aim is to align bore the holes round and truly straight with each other and the machine. just getting the size within the machining range of the bearing OD.

However, this customer has requested that I bore these to accept a .003 to .005 interference fit With the bearings out of the box.

 

[D Coots]

Break out the dry ice...

Used it when pressing bronze bearings in a swing shaft application in a Lorain TL20 Shovel 50 years ago. Jerry rigging the whole deal due to no money.....been there, done that...THE HARD WAY

Have some

 

[jackieschmidt]

Dave, we shrink a wide array of bearings in with liquid nitrogen, both metallic and non metallic.

however, the manufacturer of these bearings prohibit freezing them for installation for fear of breaking the bond between the rubber and the brass shell.

It’s no big deal to press them in, we use a 100 ton hollow ram Jack, two strong backs, and a 2 1/2 inch diameter B-7 stud.

But you are dead on, freeze in is always the best option for anything else.

You might recognize this piece we done a while back. It is the advancing spud hinge on a dredge. The dredge people call this hinge a “Chester”.

The shipyard fabricated in a new center section in the “Chester” and welded in new abutment mounts in the hull of the dredge. We came in and align bored everything. The holes are 12 inch diameter.

We machined and installed new steel bushings with liquid nitrogen. They were installed with .006 interference.
here are pictures of the boring bar in the “Chester, in the abutmentments in the barge, and a bushing submerged in liquid nitrogen, and the final install.

 

[Fuj]

My sand dredge was about half that long and had 10" suction/10" discharge. Seems like the impeller was 32" diameter. We could go 50' deep with it to the bottom of the deposit where we hit limestone. Seems like 1,250 gallon per minute pump and would produce 325 tons of sand per hour. Powered by a 575hp Cummins.

Not to jack Jackie's thread but something you would be interested in.
The John St. John sand dredge is ported here in Erie Pa, just a couple
of miles from me. it was built in 1945 and about the same length as
what Jackie is working on. Still making it's runs out on Lake Erie.

 

[Judd]

This is going to be a cool project, thanks for sharing Jackie!

 

[mikecockcroft]

Are they dredging to clear a channel or to sell sand?

 

[jackieschmidt]

We got everything laid out off of the wire today, the boring bar mounted and trued, and got a cut started.

As you can see by the pictures, it’s not the easiest thing working in this tight space, it makes me feel kinda old.

(I forgot, I am old).

I hope to get this done by Thursday.

 

[jackieschmidt]

 

[Greg Y]

I'll get some pics soon of our boring bar. We have a 102" dia job coming up soon. We're in hydroelectric and always interested in how other industry works.

 

[jackieschmidt]

I'll get some pics soon of our boring bar. We have a 102" dia job coming up soon. We're in hydroelectric and always interested in how other industry works.

We have a 8” bar, but the last job we did with it was over 20 years ago when we bored the ladder abutments on a huge “rock dredge”.
They were 48 inches in diameter.
We bored the lower housing support on a 6000 HP Rolls Royce Z Drive a couple of years ago, but we rented a Climax bar to do that. The housing was Corroded out, the shipyard welded it up with 316 stainless, the final bore size was 2500 mm, a tad under 100 inches. The Climax bar was powered by a hydraulic motor drive rather than air.

99.9% of the work we do is shaft lines and rudder tubes for inland push boats. These traveling head bars are perfect for working in tight confinements while still being able to move a lot of metal.