Chinese Sub

--What it means is the American fleet had no submarines involved in the exercise or they would have spotted it. 'Set a thief to catch a thief' and all that..

And/or that we detected it long before it got anywhere near... but aren't about the let the PRC know how good our detection capabilities are.

Thanks to Mitsubishi selling China the technology to make really, really quiet props, I don't know if it WAS detectable.

And Clinton giving away the bearing technolgy

You think those subs will be on sale at Harbour Freight soon? :}

cheers T.Alan

Don't forget, you can make your own (much stronger) by killing some hydrochloric acid with a handful of zinc. (I presume you have zinc lying around if you're galvanising stuff.) Otherwise use scrap galvanised steel.

Cheers

-- Jeff R.

Hi Rex

Curious: Any info on the bearing technology? No, I'm not going to make my own sneak sub.

Tom Gardner wrote: [...]

I remember reading about Toshiba selling propeller milling machines to the Soviets back in the '80s. Did Mitsubishi do something similar with China?

Slater

I think the company name was switched in error. I recall Toshiba myself. They did it in spite of signing documents and being paid for exclusive right due to design input by ourselves.

Mart> Tom Gardner wrote:

Gee I guess the paper needs to check it's stories. This happened LAST YEAR

During operations off Okinawa back on 26 October 2006, the Navy is saying that a Chinese Song class submarine evidently made a rather close approach to aircraft carrier USS Kitty Hawk (CV-63). The Song class boat evidently surfaced within five miles of the carrier. Whether the approach of the Song class boat was actually undetected, the Navy refuses to say. In addition to Kitty Hawk, (?the Battle Cat?), with her own air group -- the Kitty Hawk Strike Group includes a couple of cruisers, seven destroyers, and a pair of submarines, plus, most likely, satellites on call; all with a significant amount of submarine detection ability.

I think you're right, my bad.

Any cites on this?

Propeller machining technology is not THAT new.

I remember seeing a Toshiba vertical 5 axis milling machine at Dominion Engineering in Lachine, Quebec in the mid 1970's. This machine is/was a monster. The main cross beam was hinged in the middle with one milling head on each half beam. This permitted the angle of the milling planes to be adjusted for three, four, five, or six bladed propellers for simultaneous machining on 2 blades.

This company was in the business designing and building hydraulic turbines, and machining runner blades for Kaplan turbine runners was part of improving the production and hydraulic efficiency of these monster machines.

Fascinating stuff. Nowadays it is no big deal....the Chinese could easily build one themselves and, I suspect, the operating software you can get off the internet for a song. HSM types are machining gas turbine compressor and turbine wheels in their basements!!!!

The time consuming part is the hydraulic model design, testing, and optimization which has to be done for each different application. Study of hydraulic similitude (it's been a LONG time!) can minimize the number of physical experiments/studies required.

IIRC the USA submarine sonar operators were lamenting in the early

1980's that many of the Soviet ships were beginning to sound alike such that they could no longer be identified uniquely by their propeller noise, or pump noise in the case of nuclear subs.

Wolfgang

That was Toshiba, not Mitsubishi. They sold five-axis CNC milling machines, which were banned for sale to the Soviets or the Chinese, for what appeared to be a submarine-propeller machining operation. It happened around 20 years ago.

French machine tool builder Forest-Liné also got themselves in a wringer over this, having apparently sold five-axis machines to the Soviets a few years earlier.

-- Ed Huntress

I can't find any direct references. I'll bet Gunner has the poop.

This will make you nervous:

Ha-ha! Good choice of words.

The submarine detection ability is severely reduced when steaming at say 20 knots or more.

Dan

What if?

What if we spotted them earlier? Depth Charge? Admirals brig?

What if we let em think the're stealthy and sneak in and in reality we watched them for 30 miles (or so) What would the Chinese think-"We're good to go" False sense of security? Maybe

Okinawa, That'll be USA'n territorial waters then? What's the problem? there's plenty of ocean to play in :-)

Mark Rand RTFM