I'll Show You Mine, If You Show Me Yours

[deckofficer]

Originally Posted by Sailmonkey

Yep, the engine was governed at a constant speed, Off the top of my head I can't remember, 70-72 rpm or something like that.

Now I'm really intrigued. How does that work? On my last container ship, the propulsion direct drive diesel would run at 118 rpm at full ahead sea speed, 74 rpm for full ahead, with a number of rpm ranges to be avoided due to engine balance.

I have always been under the impression (but cut me slack, I'm a deckie, not an engineer) that for a given AC frequency of 50 or 60Hz, the generator has to spin at a rpm that is divisible by 60 (for 60hz) and the number of poles.

Time to teach me. At CMA, I took all the engineering courses I could fit into my deck schedule, but still missed a lot. The reason I loaded up on those classes is I didn't want "Scotty" to be able to pull the wool over my eyes like he does with Capt Kirk on Star Trek.

[David M]

Ok then, I wasn't expecting anyone to be impressed.

[deckofficer]

Originally Posted by David M

Ok then, I wasn't expecting anyone to be impressed.

Nothing like the rumble of a mighty V12, but in your case more like a high pitched giggle of a child.

[Astrid]

Reminds me of a Rolls-Royce Merlin V-12.

[deckofficer]

Originally Posted by Astrid

Reminds me of a Rolls-Royce Merlin V-12.

I'd bet you would love to fly an old warbird powered by the Merlin (P51 comes to mind). Compared to the huge radials of the day, the Merlin had less displacement but more hp.

What is your flying history? Inquiring minds what to know.

[Astrid]

I'd bet you would love to fly an old warbird powered by the Merlin (P51 comes to mind).

Would I ever!!!! Spitfire MkIX would probably be my choice (but i would probably kill myself in one). The closest I have come to anything of the sort was flying a T-6 Texan. Others flown are Piper Super cub (both wheeled and float), Morane-Saulnier 505 with radial Jacobs, and Aviat Husky float.

[Target9000]

The US National WWII museum is right down the road from where we live and when we went a while back they had a Rolls-Royce Merlin on display on an engine stand so you could walk around and see it. It was beautiful. The security had to back me away lest my drool dirty the artifact.

[deckofficer]

Originally Posted by Astrid

Would I ever!!!! Spitfire MkIX would probably be my choice (but i would probably kill myself in one). The closest I have come to anything of the sort was flying a T-6 Texan. Others flown are Piper Super cub (both wheeled and float), Morane-Saulnier 505 with radial Jacobs, and Aviat Husky float.

You are tail-dragger versatile, wish I was.

[perchance]

Originally Posted by Astrid

Would I ever!!!! Spitfire MkIX would probably be my choice (but i would probably kill myself in one). The closest I have come to anything of the sort was flying a T-6 Texan. Others flown are Piper Super cub (both wheeled and float), Morane-Saulnier 505 with radial Jacobs, and Aviat Husky float.

Saw the old Miss Supertest at the boat show last year which I believe has a Rolls Merlin in it. I sometimes watch videos on you tube just to listen to that sweet sound.

[Sailmonkey]

Originally Posted by deckofficer

Now I'm really intrigued. How does that work? On my last container ship, the propulsion direct drive diesel would run at 118 rpm at full ahead sea speed, 74 rpm for full ahead, with a number of rpm ranges to be avoided due to engine balance.

I have always been under the impression (but cut me slack, I'm a deckie, not an engineer) that for a given AC frequency of 50 or 60Hz, the generator has to spin at a rpm that is divisible by 60 (for 60hz) and the number of poles.

Time to teach me. At CMA, I took all the engineering courses I could fit into my deck schedule, but still missed a lot. The reason I loaded up on those classes is I didn't want "Scotty" to be able to pull the wool over my eyes like he does with Capt Kirk on Star Trek.

Ok,
a little further back checking/remembering. I wasn't on the ship as crew, rather as a hired gun mechanic to pull pistons on the main engine at every port. The ship was the Doctor Lykes, in a nutshell at sea speed the shaft gen is brough online, synced with the mains and then the load is bled off of the service gens. The propulsion engine is goverened at the set speed (I seem to remember the generator being a 100 pole unit) for 60hz. I was also a little off on the total power, only 2mw. The generator is attached to the front of the engine, single bearing unit. All in all a very impressive unit, and as an aside, the Doctor lykes was clean and well stocked.
Here's a link to the siemens site with some of their literature.
http://www.industry.usa.siemens.com/...ference-en.pdf