What sort of things DO NOT inspire you

Phillips had a Stirling engine powered bus in use in Holland for some years but found it too cumbersome to be practical. Too big and heavy, underpowered and averse constantly varying load conditions. But some submarines have used them running on liquid oxygen for silent(ish) underwater battery charging. Allows a diesel electric sub to stay under for weeks longer with no snorkeling.

So the energy charged into the battery ultimately comes from the work done in liquifying the oxygen? Is the sub equipped to replenish the lox, or is that a base job?

Not sure. It was all very hush hush and above my security clearance at the boatyard (Australia's Collins class subs) when I worked there 20+ years ago but I believe it was burning LOX and diesel fuel vs seawater for cooling. (How they discharge the exhaust silently is not allowed to be known by us mere mortals.) Lox refill would be a base job I imagine. Tthe government cut the program before it got to actuallity. But the Japanese have been building a similar sub built by Mitsubishi and powered by Kawasaki that is said to use the same system. So much smoke and mirrors in sub-world you can never be sure who is really doing what. But Australia was at one stage getting ready cut its existing Collins subs in half and weld in the Stirling section. The original Swedish Gotland subs had the Stirling system and could stay down 14 days instead of the couple of days diesel engines allow. One famously sneaked through US naval lines undetected and got out again,then sent them a picture of their ship taken from alongside.

Now we are getting new subs built in France, with manufacture to be transferred here after the first one. The Renault of submarines. Great. Problem is that in the meantime Australia's manufacturing industry has declined so far there is nobody left here of working age with the engineering trade skills to build them or the subcontracted components. So they will be mostly pre-fabbed in France, shipped here and put together by foreign workers. Now THAT's uninspiring.

Edited By Hopper on 26/02/2020 09:34:25

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The Thought Police and others who assume they occupy the moral high ground and can therefore prohibit free speech.

I was one of the earliest responders to this thread. I posted "Politicians". It was a well thought-through, entirely thruthful and unusually succinct post. OP Bill Chugg quite reasonably asked that the thread confine itself to engineering-related topics. He hasn't been successful. Now our two posts seem to have vanished. Is this the heavy hand of the moderators? Why should politicians be protected from criticism? C'mon moderators, be reasonable.

The thread has strayed well away from engineering matters. Is it any the worse for that? I find it quite entertaining - after all, there's quite a significant proportion of Grumpy Old Men in the brotherhood.

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The Gotland class sub is still in service with the Swedish navy. While submerged, the Kockums-built Stirling engine AIP system is used to drive a 75kW (101 shp)  generator for either propulsion or charging the batteries.

Wikipedia *** LINK ***

John

Edited By Journeyman on 26/02/2020 10:36:49

Interesting. Thanks. Kockums were the partner in the Aussie built Collins version. Communication was a disaster. When stuff did not work on commissioning, nobody spoke English all of a sudden.

Although the thread may have drifted at least it has not drifted into politics which it may well have done had I not deleted those posts.

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I can't visualise that 2x101 shp would provide *inspiring* propulsion in a sub of around 1600t submerged.

Apparently - Surfaced: 11 knots (20 km/h) or submerged: 20 knots (37 km/h) on batteries; 5 knots (9.3 km/h) on AIP (Air-independent Propulsion). Doesn't sound overly speedy but good for creeping about undetected.

John

Edit: Remove spurious link from copied text.

Edited By Journeyman on 26/02/2020 13:12:41

Things like this that end up costing the NHS a lot of money in bone repairs & joint implants in later life when they realise it did not make them more healthy. It just wore them out quicker. Cyclists in London. Phew.    

Steve.

Edited By Steviegtr on 27/02/2020 01:44:11

And creeping about is what that class of sub is all about. It is a strange world of smoke and mirrors, sneaking past other vessels, surveillance, listening, monitoring radio waves etc. And of course they do carry torpedoes in case they are needed. So they actually spend a lot of time just sitting there, or going dead dead slow, watching, listening, waiting. The Stirlings recharge the batteries while they do that. Big progress coming too with Lithium Ion batteries instead of the old acid-sloppers.

Modern cars and motorcycles don't inspire me even a little bit. Sure they are amazingly reliable, go well enough, but I find them sooooo boring. Just transport!!

Hopper wrote...."...One famously sneaked through US naval lines undetected and got out again,then sent them a picture of their ship taken from alongside. " My late brother was in the RN, he served in conventional boats for 15 years, he told a couple of tales, this was one of them. It would have been in the late 60s or early 70s, Chris was on HMS Artemis, they had sailed across the Atlantic and the crew were vaguely surprised that she had made it across. They rendezvoused with a USN escort off the naval dockyard (Newport News???) being visited. The plan was to submerge and then sail into the middle of the dockyard whilst the USN tracked them, both from ashore, with their highly sophisticated submarine detection equipment and afloat. After a while the Artemis popped up in the middle of the dockyard. The USN didn't believe it, "...you cannot be here, we didn't see or hear you, you must have cheated...". So they had to exit the dockyard, and do it all over again, still not detected!!

Sorry for straying, it's what I do!!

cheers

Bill

Hit & Miss engines (when they're running).

When I see a video of a Hit and Miss running I just want to reach into the screen and give it a helping 'push' to make it fire evenly on every revolution. I suppose it's just a personal idea that engines should have a steady, repeating sound.

I don't think I would ever want to make a model of one. Sorry to the Hit and Miss enthusiasts.

Ed.

Ed, if you also made something for it to drive you would find that the load will have it firing on every beat, most videos tend to show them ticking over doing nothing, I'm sure you don't sit at the traffic lights with your right foot to the floor even if you do like the sound

Watch the end of this one where I put my hand into the video for you and it starts to fire on each power stroke.

Edited By JasonB on 27/02/2020 07:02:57

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Sounds just like my Ducati .

Steve.