APDS (I think) = Armor-Piercing Discarding-Sabot rounds are kinetic-energy killers. The penetrator is necessarily a dense material, usually either depleted uranium or tungsten. Note that shot-guns may also use sabots for flechetes. I guess one could think of the patch around a musket ball as a sabot too. ;-)
that was horrible! shame on you :(
Legible Cheers, Terry
ripping the fan off a vacuum cleaner motor so it runs unloaded is fun too - just stand well clear.
Cheers Terry
It depends on what you want to remain constant. If you are keeping the horsepower constant, then reducing the rpm by half will cause the torque to be twice as much. power = angular velocity x torque x (some correction factor to make all the units work together) using horsepower, foot pounds, and rpm HP=(rpm)(torque)/5260.
+ACY-lt;jjlarkin+AEA-highlandSNIPtechTHISnologyPLEASE.com+ACY-gt; wrote in
Yep, the same as my US Navy. But the lower-level watch changes the main lube-oil strainer once a watch. Care to guess what sort of things can be dropped into a strainer housing while the strainer is removed? Even just buttons off your sleeve or a pair of dolphins off your shirt. Not always deliberate, but lets face it, it happens. And the gears chew em up and grind em to bits. But that leaves a mark on the gear.
Ditto for the lube oil sump when its open for inspection/cleaning. The close-out of the sump is signed off by an officer. Some junior officers don't bother to leave the ward-room to perform that inspection.
Navy has been using FOD (Foreign Object Damage) prevention practices for a long time. Yes, the engineer has the key to the locks on the reduction gear and the sailors setup a tent over the gear and go through a lot to put lanyards on all tools, and log everything in and out. But guess what, sh** still happens.
daestrom
Depends on the situation I guess. IMA and 'depot' level maintenance opens them up fairly routinely. But like I mentioned in my other post, the lube oil system isn't so tightly controlled. The strainer is swapped every watch by 'lower-level louie'. And when the sump is opened up for clean/inspect, it is usually some junior officer that does the close-out inpsection (not a very easy job to do).
Small crap *does* get in them despite all the precautions. Doesn't put a gear OOC, but does leave its 'mark' on things. Buttons, 2nd-class metal 'crow' insignia, dolphins, 'tweakers', you name it. Some identifiable remains, some just bits of plastic/metal.
daestrom
Yes, "The Undiscovered Country". When coming up with an excuse why the Enterprise could not return to base as ordered, the young female Vulcan explains the Dutch history of the word.
daestrom P.S. And yes, a 'sabot' is also a drop-away casing around irregularly shaped objects used to make them fit in a gun barrel.
Interesting. Sort of a turbine assisted ramjet.
- YD.
IIRC, sabotage, saboteur and the like come from the french word for wooden shoe. In the early days of industrialisation these shoes were dropped into the maschines by workers when they wanted a rest. The shoes would jam somewhere and stop the maschine.
AFAIK, they use diesel-electric coupling.It's called Ward-Leonard coupling, also a DC-geberator and motor.
-- Dimitris Tzortzakakis,Iraklion Crete,Greece Analogue technology rules-digital sucks
------------ There are motors which exceed 100MVA - and 50MVA is relatively common but not at all small. As for speed- I don't know the limits- but the problems become basically mechanical rather than electrical.
----------------------------------- The problem is that a jet turbine has a better power/weight ratio than an electric motor. In an aircraft this is considered to be important.
I have worked with 3MVA pump motors (big pumps) and a friend of mine built a soft-starter for a 50MVA synchronous machine used in a hydro power station
cheers Terry
just as a reference, the large motor guys have worked with the large adjustable speed drive guys to achieve some impressive super-synchronous feats. I was involved with a 3500 Hp 2 pole motor that with the ASD at top frequency would put out 11,500 rpm. And yes, keeping the rotor and bearings together was more a mechanical problem than electrical. jtiggr
now thats honking! the best I can manage is a 730Hz inside-out PMSM that stored 3MJ in the rotor (J=0.25 in SI units IIRC). the DSP for that puppy was quite tricky, as we were sampling comparatively slowly (BLT, internal model control, blah blah blah)
cheers Terry
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