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Turbine engines

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Re: Turbine engines
Post by Louis R   » Fri May 27, 2016 12:18 pm

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It's been implied that there are a lot more incidents than we see. Most are minor enough to be no more than a hiccup in the over all story - if not in the lives of those involved - and that's precisely why we don't see them, any more than we see such things in accounts of the air war over Europe. My mother has said that she spent a good chunk of WWII with no eyebrows - the hydrogen she was filling 'radio tubes' [my guess is they were thyratrons] with kept leaking and exploding. Multiply that by a few million, and you have some idea of how many stories get left out of any story, because they really only matter to the characters in them.

Silverwall wrote:
Captain Igloo wrote:The open-hearth steelmaking process was fairly typical of the industry around 1900 and didn't required a lot of highly trained engineers. Each operating furnace was attended by three men: a first helper, a second helper, and a cinder pit man (or third helper).

Supervising the work was a foreman (melter foreman or simply melter) who was in charge of the operation of all the furnaces. The first helper was in charge of "his" furnace, except when the heat was tapped. The duty of the first helper was to work the heat: direct the work of the second helper and cinder pit man; inform them, along with the charging machine operator, how much ore, pig iron, scrap, and other materials were to be added to the furnace; run off the slag; and direct any repairs necessary during the operation. The main responsibility of the first helper was to tap the heat, direct the repair of the bottom, and clean the steel spout.

The second helper had the most difficult job: he had the responsibility of keeping supplies of dolomite (for "making bottom" and performing repairs of the furnace as the heat worked) as well as ladle additives on hand. This was was done manually (with shovel and wheelbarrow) at some sites. The second helper helped work the heat, dug the plug out of the tapping hole when the heat was ready to tap, plugged the tapping hole after the heat, relined the steel spout after the heat, and cleaned-up around the furnace.

The cinder pit man cleaned the cinder pit and assisted in "making bottom" at the furnace. The melter foreman had overall direction of the furnaces. The melter also made sure that the heat met the specifications of the order, took charge of any furnace when difficulty arose, directed the tapping of the heat and any ladle additions, and inspected the bottom of the furnace after the heat was tapped.

This work (especially that of the second helper and cinder pit man) was laborious, hot, dirty and dangerous, but you don't need to be a rocket scientist. Most workers in the steel industry were immigrants - Italians, Slovaks, Poles, Croatians, Hungarians, Greeks and Ukrainians.


I was thinking more of the engineers needed to run all these devices rather than factory workers. This was a real problem historically whenever new tech was introduced to the military with the victorian navy hit particularly hard at times.

The other issue is that no-one has a technical mindset yet. This is a really big thing as I see every week in real life. I work regularly with very smart postgraduate students from countries which don't have the levels of technical penetration we take for granted in the West. The ammount of extra work they have to do to succeed is supprising, things we take for granted must be learned the hard way. They are sharp as tacks but lack the technical experiance to inform instinctive decisions you find in even non technical students from the more developed countries. To Translate to Safehold we should see wayyyyyy more industrial accidents and mistakes and user errors than we do.

Basically the Flynn effect in action https://en.wikipedia.org/wiki/Flynn_effect. This is a problem that would be huge on Safehold but we don't see it because it would make a poor story element.
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Re: Turbine engines
Post by Keith_w   » Sat May 28, 2016 7:30 am

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AirTech wrote:
This is the old issue the military face with breaking in new ensigns, the warrant officers know their job better by far but are expected to take orders from officers who may not yet know the depths of their incompetence. Generally officers are their to do the paperwork, the warrant officers are their to make sure the job is done right. Similarly most engineers shuffle paper and the technicians actually maintain the equipment. An new graduate engineer with a spanner in his hand is just plain dangerous. It takes three to four years before they are safe to work around.


I guess that is the point of the "How to raise a flag pole" story.
--
A common mistake people make when trying to design something completely foolproof is to underestimate the ingenuity of complete fools.
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Re: Turbine engines
Post by Jonathan_S   » Tue May 31, 2016 11:53 am

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saber964 wrote:The biggest sticking point with turbine engines is reduction gears. A turbine engine is optimal at high speed like 5-10k RPM conversely marine engines work best at slower speeds like 250-300 RPM. The destroyer I served on used LM 2500 engine, the same engine used on the DC-10. But the shafts only turned IIRC at a maximum of 350 RPM. I remember watching the replacement of a reduction gear at Long Beach NSY. The gear they pulled was the size of a small car and weighed 15-20 tons and took almost three months to manufacture a replacement. Reduction gears are known in naval construction as a long lead item meaning that they are ordered oftentimes years in advance of installation. I wouldn't be surprised if the current federal budget has a line item authorizing funding for the reduction gears for the carrier Enterprise which is scheduled for commissioning in 2025.

FYI the U.S. used triple expansion engines on some Liberty and Victory ships to speed up construction of the ships because of the bottle neck in manufacturing reduction gear.
Also some other ships of the era, like the Buckley-class destroyer escorts, went with turbo-electric machinery as a different way to bypass that reduction gear manufacturing bottleneck.
Though that option isn't open to Safehold; not while the proscriptions hold.
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Re: Turbine engines
Post by saber964   » Tue May 31, 2016 5:22 pm

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Jonathan_S wrote:
saber964 wrote:The biggest sticking point with turbine engines is reduction gears. A turbine engine is optimal at high speed like 5-10k RPM conversely marine engines work best at slower speeds like 250-300 RPM. The destroyer I served on used LM 2500 engine, the same engine used on the DC-10. But the shafts only turned IIRC at a maximum of 350 RPM. I remember watching the replacement of a reduction gear at Long Beach NSY. The gear they pulled was the size of a small car and weighed 15-20 tons and took almost three months to manufacture a replacement. Reduction gears are known in naval construction as a long lead item meaning that they are ordered oftentimes years in advance of installation. I wouldn't be surprised if the current federal budget has a line item authorizing funding for the reduction gears for the carrier Enterprise which is scheduled for commissioning in 2025.

FYI the U.S. used triple expansion engines on some Liberty and Victory ships to speed up construction of the ships because of the bottle neck in manufacturing reduction gear.
Also some other ships of the era, like the Buckley-class destroyer escorts, went with turbo-electric machinery as a different way to bypass that reduction gear manufacturing bottleneck.
Though that option isn't open to Safehold; not while the proscriptions hold.



The U.S. did a lot of that. You also forgot about the other DE's like the Evarts class. These ships came with a multitude of engines IIRC the had Turbine-Electric, Diesel-Electric, Diesel, Steam-Turbine and some were going to be built with Triple Expansion steam engines. It's all in the headings of the classes IIRC WTG stood for Westinghouse Turbo Generator and FMR stood for Fairbanks Morris.
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Re: Turbine engines
Post by chrisd   » Wed Jun 01, 2016 12:39 pm

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Jonathan_S wrote:
saber964 wrote:The biggest sticking point with turbine engines is reduction gears. A turbine engine is optimal at high speed like 5-10k RPM conversely marine engines work best at slower speeds like 250-300 RPM. The destroyer I served on used LM 2500 engine, the same engine used on the DC-10. But the shafts only turned IIRC at a maximum of 350 RPM. I remember watching the replacement of a reduction gear at Long Beach NSY. The gear they pulled was the size of a small car and weighed 15-20 tons and took almost three months to manufacture a replacement. Reduction gears are known in naval construction as a long lead item meaning that they are ordered oftentimes years in advance of installation. I wouldn't be surprised if the current federal budget has a line item authorizing funding for the reduction gears for the carrier Enterprise which is scheduled for commissioning in 2025.

FYI the U.S. used triple expansion engines on some Liberty and Victory ships to speed up construction of the ships because of the bottle neck in manufacturing reduction gear.
Also some other ships of the era, like the Buckley-class destroyer escorts, went with turbo-electric machinery as a different way to bypass that reduction gear manufacturing bottleneck.
Though that option isn't open to Safehold; not while the proscriptions hold.


There is also a benefit to "turbo-electric" propulsion in that you don't need separate "Astern" and/or "Manoeuvring" turbines.

The turbine being uni-rotational, the generator-motor combination gives speed control and reversing similar to a "Ward-Leonard Set"
Last edited by chrisd on Sat Jun 18, 2016 8:10 am, edited 1 time in total.
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Re: Turbine engines
Post by DDHv   » Wed Jun 01, 2016 11:29 pm

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AirTech wrote:
snip

Something you find missing in pretty much every third world country are decent trade schools. With no professional training of tradesmen you have people who have learnt from experience but lack the technical knowledge behind what they are doing. In most first world countries the trades staff and technicians are at least as well trained technically as a third world bachelors degree holder but have at least four years industrial experience before they will let an apprentice loose on his own.
This is the old issue the military face with breaking in new ensigns, the warrant officers know their job better by far but are expected to take orders from officers who may not yet know the depths of their incompetence. Generally officers are their to do the paperwork, the warrant officers are their to make sure the job is done right. Similarly most engineers shuffle paper and the technicians actually maintain the equipment. An new graduate engineer with a spanner in his hand is just plain dangerous. It takes three to four years before they are safe to work around.


IMNHO, the current tendency to push most people to college instead of trade training is a major mistake. I had engineering college, but they also required us to take practical courses. At least, when we (later) had to rework an engine, there was enough experience to know the need to act as a helper instead of trying to give all the orders.

Electricity and control system were largely learned on my own - these are more theoretical, but you can still foul things up. Which is why I'm occasionally called back by my former boss - the replacement guy knows more hydraulics than I, but lacks control system practicum
:|
Last edited by DDHv on Sat Jun 04, 2016 5:14 pm, edited 1 time in total.
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Re: Turbine engines
Post by PeterZ   » Thu Jun 02, 2016 12:40 am

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fallsfromtrees wrote:
PeterZ wrote:The tripples were used in both the blast furnaces and KH VIIs.

Textev, sil vous plait

http://forums.davidweber.net/viewtopic.php?f=7&t=4116&hilit=hms+shan+wei

Not textev but an infodump on the forum
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Re: Turbine engines
Post by AirTech   » Sat Jun 04, 2016 7:25 am

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Jonathan_S wrote:
saber964 wrote:The biggest sticking point with turbine engines is reduction gears. A turbine engine is optimal at high speed like 5-10k RPM conversely marine engines work best at slower speeds like 250-300 RPM. The destroyer I served on used LM 2500 engine, the same engine used on the DC-10. But the shafts only turned IIRC at a maximum of 350 RPM. I remember watching the replacement of a reduction gear at Long Beach NSY. The gear they pulled was the size of a small car and weighed 15-20 tons and took almost three months to manufacture a replacement. Reduction gears are known in naval construction as a long lead item meaning that they are ordered oftentimes years in advance of installation. I wouldn't be surprised if the current federal budget has a line item authorizing funding for the reduction gears for the carrier Enterprise which is scheduled for commissioning in 2025.

FYI the U.S. used triple expansion engines on some Liberty and Victory ships to speed up construction of the ships because of the bottle neck in manufacturing reduction gear.
Also some other ships of the era, like the Buckley-class destroyer escorts, went with turbo-electric machinery as a different way to bypass that reduction gear manufacturing bottleneck.
Though that option isn't open to Safehold; not while the proscriptions hold.


An alternative would be a hydraulic drive with a centrifugal pump unit but best efficiency would require a large diameter turbine to get the rotational speed down to below 5000 rpm to drive the pump whilst keeping the turbine blades running close to sonic velocity for best efficiency. An alternative could be a radial gas turbine or an uncoupled free turbine stage (similar to the Avro VZ-9 engine) which has a low enough RPM for direct drive but the gyroscopic effects would be interesting in a ship given its large size.
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Re: Turbine engines
Post by PeterZ   » Sat Jun 04, 2016 5:23 pm

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Textev is in LaMA, September YOG 896 chapter II almost at the end with Howsmyn, Rock Point, Pine Hollow and Ironhill discussing production plans.



fallsfromtrees wrote:
PeterZ wrote:The tripples were used in both the blast furnaces and KH VIIs.

Textev, sil vous plait

http://forums.davidweber.net/viewtopic.php?f=7&t=4116&hilit=hms+shan+wei
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Re: Turbine engines
Post by fallsfromtrees   » Sun Jun 05, 2016 11:43 am

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PeterZ wrote:Textev is in LaMA, September YOG 896 chapter II almost at the end with Howsmyn, Rock Point, Pine Hollow and Ironhill discussing production plans.

fallsfromtrees wrote:Textev, sil vous plait

http://forums.davidweber.net/viewtopic.php?f=7&t=4116&hilit=hms+shan+wei

Thank you for the link - it was from before my time here, and I had never seen it before - fascinating.
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