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View Full Version : HMAS Shropshire, and the not mentioned defect.



bob10
22nd March 2016, 07:09 AM
Luckily, Australian Navy engineers were up to the task.

https://www.flickr.com/photos/41311545@N05/5601623775/in/photostream/

jx2mad
22nd March 2016, 07:51 AM
British engineering? Sounds like a LANDROVER :)

squizzyhunter
22nd March 2016, 08:57 AM
I had to look up how a thrust pad worked...

Pre WW1 a solid block was used for a prop shaft thrust bearing that needed a constant oil feed and was one of the main limiting factors in moving to more powerful engines at that time also obviously a pretty short service life. In 1905 an Aussie engineer called George Michell came up with "sector-shaped pads, arranged in a circle around the shaft, and which are free to pivot. These create wedge-shaped regions of oil inside the bearing between the pads and a rotating disk, which support the applied thrust and eliminate metal-on-metal contact" (wikki). This new "Michell bearing" was 10 times smaller, had much longer service life and didnt need an oil pump, the prop shaft rotation distributed the oil. They are still the standard bearing used on turbine shafts in ships and power plants worldwide today.

bob10
22nd March 2016, 09:30 AM
I had to look up how a thrust pad worked...

Pre WW1 a solid block was used for a prop shaft thrust bearing that needed a constant oil feed and was one of the main limiting factors in moving to more powerful engines at that time also obviously a pretty short service life. In 1905 an Aussie engineer called George Michell came up with "sector-shaped pads, arranged in a circle around the shaft, and which are free to pivot. These create wedge-shaped regions of oil inside the bearing between the pads and a rotating disk, which support the applied thrust and eliminate metal-on-metal contact" (wikki). This new "Michell bearing" was 10 times smaller, had much longer service life and didnt need an oil pump, the prop shaft rotation distributed the oil. They are still the standard bearing used on turbine shafts in ships and power plants worldwide today.

The old Mitchell thrust pads. I'd like a pound for every time I've removed & inspected them. On the DDG Brisbane, back in 1977, It was known that the Port shaft main turbine thrust bearing had an issue with overheating. For a period , every time we came alongside during a trip, we engine room tiffies had to remove, inspect & photograph the thrust pads. Brisbane had to do a pre refit full power trial up the coast from Melbourne to Sydney. And once again, the bearing overheated.

Coming alongside Garden Island, an army of Dockyard boffins descended into 2 Engine room, we removed the pads and displayed them for all to see. There was much scratching of chins, wise murmuring, and then they left. All except a last year Dockyard apprentice. He had the original engineering drawings of the offending article, and seemed genuinely bemused. He called the two of us over, and said " does that look right? " What he was indicating was , on the drawing, a lube oil drain hole was shown on the casing, but wasn't on our bearing casing. A quick call to our Engineer had more dockyard matey's down the hole than you could imagine. A eureka moment. The apprentice was pushed to the rear, in the commotion, but I can't help thinking he had a bright future. Problem solved. It had been supplied like that from new. And yes, Mitchell thrust bearings had an oil supply, supplied by the turbine lube oil pump.

bob10
22nd March 2016, 09:35 AM
Mitchell thrust bearings

Tilting Pad Thrust Bearings (http://www.machinerylubrication.com/Read/906/tilting-pad-thrust-bearings)

Lotz-A-Landies
22nd March 2016, 10:08 AM
I still prefer the Aussie accessories on the afterdeck of the HMAS Queenborough!

https://www.aulro.com/afvb/images/imported/2016/03/292.jpg

squizzyhunter
22nd March 2016, 10:32 AM
Mitchell thrust bearings

Tilting Pad Thrust Bearings (http://www.machinerylubrication.com/Read/906/tilting-pad-thrust-bearings)

So are the KingCole LEG bearings standard issue now? I thought that was a lot of faith to have in a sealed system.

bob10
22nd March 2016, 07:47 PM
I still prefer the Aussie accessories on the afterdeck of the HMAS Queenborough!

https://www.aulro.com/afvb/images/imported/2016/03/292.jpg

The sailors?

bob10
22nd March 2016, 07:56 PM
So are the KingCole LEG bearings standard issue now? I thought that was a lot of faith to have in a sealed system.

Don't know what they have now. I belonged to the steam era, back in the age of dinosaurs, " up one stokes!" ,splash lubricated shaft bearings, lignum vitae stern bearings. Those were the days, no air conditioned MCR's, hands on steaming. Back in the day when if it was broke, you were told to fix it. No spares? as one infamous Engineer would say " make a bastard! ".

Lotz-A-Landies
22nd March 2016, 08:50 PM
The sailors?Only if they're cute and particularly if they are driving the 80"Landy.

It must be difficult when they have to drive it up to the bridge. :D

bob10
22nd March 2016, 08:59 PM
Only if they're cute and particularly if they are driving the 80"Landy.

It must be difficult when they have to drive it up to the bridge. :D

Your eyes are much better than mine. There would be an interesting story behind that.

JDNSW
22nd March 2016, 09:02 PM
Don't know what they have now. I belonged to the steam era, back in the age of dinosaurs, " up one stokes!" ,splash lubricated shaft bearings, lignum vitae stern bearings. Those were the days, no air conditioned MCR's, hands on steaming. Back in the day when if it was broke, you were told to fix it. No spares? as one infamous Engineer would say " make a bastard! ".

Not from the days of "Down funnel, up propeller, hoist sails"?

John

JDNSW
22nd March 2016, 09:04 PM
The sailors?

I suspect she is referring to the Landrover.

John

Lotz-A-Landies
22nd March 2016, 10:23 PM
Your eyes are much better than mine. There would be an interesting story behind that.There were a whole bunch of 80"Landies purchased by the RAN in the early 1950s. HMAS Quadrant had one as did HMAS Tobruk when it was deployed to the Korean War.

This is Quadrant.

https://www.aulro.com/afvb/images/imported/2016/03/281.jpg

Note the Land Rover on the afterdeck immediately behind the superstructure.

bob10
23rd March 2016, 07:26 AM
The " Q " class story.

HMAS Quadrant | Royal Australian Navy (http://www.navy.gov.au/hmas-quadrant)

bob10
25th March 2016, 04:17 PM
Not from the days of "Down funnel, up propeller, hoist sails"?

John

Get it right. Extra training in the first dog, that man.



Hands aloft! Up screw, loose topsails, set staysail and jib