Imaginary Locomotives

[PenrithBeacon]

15 minutes ago, Northmoor said:

No, No and No, in that order.

Water is a liquid made up of two elements, Hydrogen and Oxygen.  You are confused by thinking of them as gases because that is what H2 and O2 would be at room temperature (or indeed any other temperature humans can withstand).  H20 can exist, like any element or molecular compound, in one of three phases: solid, liquid or gas (there's also plasma but that's at extremes of temperature and largely theoretical).  Iron can be a gas if you get it hot enough. 

There is no such thing as a Vapeous 

Well that is what I was taught at school and I have a dvd  in my library in which Prof Brian Cox says the same!

I think we'll have to agree to disagree 

[DK123GWR]

https://en.wikipedia.org/wiki/Steam

https://en.wikipedia.org/wiki/Vapor

A vapour is a gas which can be condensed into a liquid by increasing pressure without needing to reduce the temperature. Hence, if something is a vapour, it must also be a gas, however it is possible to be a gas without being a vapour.

 

Steam is a gas (specifically water in its gaseous phase). Below 647K (the critical temperature of water), steam is also a vapour as it can be condensed into liquid water by increasing the pressure. Above 647K, steam would no longer be a vapour as it is imposible to condense it to liquid water above this temperature.

[Compound2632]

57 minutes ago, PenrithBeacon said:

Well that is what I was taught at school and I have a dvd  in my library in which Prof Brian Cox says the same!

I think we'll have to agree to disagree 

 

Sorry, the difference between an element, a molecule, a compound, and a mixture gets drummed into year 7 pupils, whilst the three states of matter is covered in year 8 at the latest. @Northmoor would do well in the end of topic test, evidently young Cox - or his scriptwriters - would not!

 

As mentioned above, what one sees billowing out of the chimney of a steam locomotive is a mixture of incompletely combusted particulate matter (smoke) and water vapour droplets formed from condensed steam; the formation of droplets being seeded by the smoke particles. Atmospheric conditions can have a significant effect - I vividly remember a visit to the Cholsey & Wallingford on a cold damp April day some twenty-five years ago - the locomotive was enveloped in great clouds of vapour.

 

 

[Compound2632]

4 minutes ago, DK123GWR said:

A vapour is a gas which can be condensed into a liquid by increasing pressure without needing to reduce the temperature. Hence, if something is a vapour, it must also be a gas, however it is possible to be a gas without being a vapour.

 

Although in the context of a steam locomotive exhaust, it is the reduction in temperature that is the cause of condensation. (There is also a reduction in pressure taking place, as the steam expands after being exhausted from the blast pipe.)

[rodent279]

Well, I reckon that was possibly the most informative 5 min I've had on RMWeb!

In Level 3 Engineering Science, and 1st yr Physics at University, I was taught that steam is invisible, as it's a gas, and that when you see white stuff, it is not steam, but a cloud of fine water droplets. In fact, the visible part of a locomotive exhaust is really the same as a cloud in the sky, just at a higher temperature.

[DK123GWR]

15 minutes ago, rodent279 said:

I was taught that steam is invisible, as it's a gas,

Chlorine is a gas at room temperature, and I'm quite certain its a green-ish colour.

https://en.wikipedia.org/wiki/Chlorine#:~:text=The second-lightest of the,green gas at room temperature.

 

Open the 'uses and properties' box.

https://www.rsc.org/periodic-table/element/17/chlorine#:~:text=Chlorine is yellowy-green in colour%2C as is the image.&text=A yellowy-green dense gas with a choking smell.&text=Chlorine kills bacteria – it is a disinfectant.

Edited December 29, 2020 by DK123GWR
Added wiki link, and again to add Royal Society of Chemistry link

[rodent279]

1 hour ago, DK123GWR said:

Chlorine is a gas at room temperature, and I'm quite certain its a green-ish colour.

https://en.wikipedia.org/wiki/Chlorine#:~:text=The second-lightest of the,green gas at room temperature.

 

Open the 'uses and properties' box.

https://www.rsc.org/periodic-table/element/17/chlorine#:~:text=Chlorine is yellowy-green in colour%2C as is the image.&text=A yellowy-green dense gas with a choking smell.&text=Chlorine kills bacteria – it is a disinfectant.

I did wonder if I'd get tripped up on that!

[The Johnster]

I was taught in school that steam is an invisible gas, proven by the fact that you can’t see it as it leaves the spout of a boiling kettle for an inch or so.  The stuff you can see is water vapour, which is no longer steam as it has condensed into droplets of liquid water.  It is, therefore, water and only described as vapour because the droplets are small and light enough to be airborne. 

[Gibbo675]

7 hours ago, The Johnster said:

I was taught in school that steam is an invisible gas, proven by the fact that you can’t see it as it leaves the spout of a boiling kettle for an inch or so.  The stuff you can see is water vapour, which is no longer steam as it has condensed into droplets of liquid water.  It is, therefore, water and only described as vapour because the droplets are small and light enough to be airborne. 

Hi Johnster,

 

All this gassing on and steamed up talk is giving me a "Case of the Vapors !!!"

 

Gibbo.

[Clive Mortimore]

I have an idea of an imaginary loco powered by flatulence, sourced from a group of RMwebbers trying to out do each other with their CSE physics. 

[john new]

2 minutes ago, Clive Mortimore said:

I have an idea of an imaginary loco powered by flatulence, sourced from a group of RMwebbers trying to out do each other with their CSE physics. 

With the depot fed by tanker trains from that well known company - Flatuline.

[Gibbo675]

1 minute ago, Clive Mortimore said:

I have an idea of an imaginary loco powered by flatulence, sourced from a group of RMwebbers trying to out do each other with their CSE physics. 

Hi Clive,

 

I rooted through the Spice rack in an attempt to Fold Space in the way of the Navigators so as to do away with locomotives completely, however It turns out that Cayenne Pepper is not the way forward, my eyes turned Red instead of Blue !

 

Frankly I'm a bit of a Herbert.

 

Gibbo.

[Compound2632]

1 hour ago, Clive Mortimore said:

I have an idea of an imaginary loco powered by flatulence, sourced from a group of RMwebbers trying to out do each other with their CSE physics. 

 

Similar but not quite the same: there is or was a pumping engine in the basement of the Palace of Westminster for the hot water heating system. It's a hot air engine, powered from the debating chambers.

[The Johnster]

Better power source might be the froth from the Hornby 2021 Hopes thread.  

[The Johnster]

2 hours ago, Compound2632 said:

 

Similar but not quite the same: there is or was a pumping engine in the basement of the Palace of Westminster for the hot water heating system. It's a hot air engine, powered from the debating chambers.

The Welsh Assembly Government building is, genuinely, heated and ventilated by dicts carrying the warm air generated in the debating chamber.  If you’re in the area, it’s open to the public and does a very good, and subsided cheap, cream tea...

[RLBH]

On 28/12/2020 at 18:11, ScottishRailFanatic said:

I understand what you mean - I was thinking more along the lines of small branch lines, probably near heritage railways to assist maintenance. Coal may still run at that point as the nearby heritage lines would have some on hand anyway. Probably tank engines, like the 14XX class of the Great Western, which could give any modern EMU a run for its money in terms of speed.

The only place modern coal-fired steam would have a hope of competing economically would be hauling massive coal trains. Very much along the ACE 6000 line of thinking, which means not in the UK. Maybe in China, Australia or some other massive coal exporter. But almost certainly not – diesel-electric and straight electric have all the cards. 

[AlfaZagato]

Even the UP saw no money in returning to revenue steam.   For all of their coal fields, none in the UP's territory produce any quantity of decent coal.   Big Boy's oil-fired right now, and will likely stay that way for the foreseeable future.

 

Sadly, short of self-propelled freight, fully automated and driverless locomotives, or some truly revolutionary new power source, I think we may have hit the zenith of locomotive development.    Anything I could see forthcoming in my lifetime is simply evolutions of a theme.   Even ol' EMD has modernized to a four-stroke motor, for Pete's sake.

 

Which is why I like retroactive what-if's best.   Like, what if LNER had pursued the Armstrong-Whitworth 'universal' diesel?  Would they have been classified as a V?  Would they have worn Apple Green?  What would have Gresley done to make it to his liking? (Probably compound the diesel motor somehow.)

[PhilJ W]

Steam can be generated chemically. I'm not sure of the chemistry involved but Germany were the leaders in the field in the 1930's/40's.  They were even considering using the technology to power a U-boat. It was used to power the Me163 Komet rocket plane. The biggest problem was that the fuel, hydrogen peroxide was pretty nasty stuff and needed special handling. 

[The Johnster]

Another possible application for steam might be in cases of entirely electrified systems where motive power is needed when the juice is off.  Steam locos are cheaper to build than diesel, so have less need to be intensively used to pay off the loan that bought them, and are simpler to maintain; a steam loco in such a role might last for many years before needing replacement.  They are not affected by long periods of inactivity, and this role does not require much in the way of speed, so hammer blow is less of an issue. 
 

I don’t agree that steam has reached it’s ultimate development, as electronic boiler management enabling single manning has not been investigated, neither has gas firing. 
 

But I think it is very unlikely that we will ever see further development in steam or locos built to new designs, unless it is connected with the heritage/tourist/leisure application.  The electrified railway maintenance role can be done on battery, or by off the shelf diesels which might be hired in if that’s cheaper, there would need to be a very specific need.  

 

[The Johnster]

8 minutes ago, PhilJ W said:

Steam can be generated chemically. I'm not sure of the chemistry involved but Germany were the leaders in the field in the 1930's/40's.  They were even considering using the technology to power a U-boat. It was used to power the Me163 Komet rocket plane. The biggest problem was that the fuel, hydrogen peroxide was pretty nasty stuff and needed special handling. 

Much of what the Germans did in this period is not economically viable in a peacetime role where an unlimited supply of forced labour is not available or acceptable.  Their economic philosophy was unworkable and a major factor in their defeat; they were undeniably world leaders in industrial chemistry for most of the 20th century

[Northmoor]

3 minutes ago, The Johnster said:

Another possible application for steam might be in cases of entirely electrified systems where motive power is needed when the juice is off.  Steam locos are cheaper to build than diesel, so have less need to be intensively used to pay off the loan that bought them, and are simpler to maintain; a steam loco in such a role might last for many years before needing replacement.  They are not affected by long periods of inactivity, and this role does not require much in the way of speed, so hammer blow is less of an issue. 

Steam locos were cheaper to build when they came off a production line, but the build-cost of one-off steam locos now closely matches new diesel locos.  Unfortunately, the economics of steam are affected by long periods of inactivity, as the "clock" on a boiler certificate starts counting from the first pressure cycle, so even if you don't use the loco for a year, you've still lost a year's worth of boiler life.  A diesel loco started every month to warm it through and dry off any condensation will, with light maintenance, last almost forever; look at the Class 08.

I would also argue that the infrastructure for running steam locos is greater; while you can have coal deliveries, generally you'll need additional coaling equipment to get it into a bunker or tender and you can't ask the fire brigade to supply water for a whole weekend of steam services, you need a high flow rate water supply installed for topping up.  Meanwhile, a low mileage diesel loco just needs a fuel lorry with industry standard hose connections, to turn up with a few hundred gallons, as required.

[The Johnster]

4 hours ago, Northmoor said:

Steam locos were cheaper to build when they came off a production line, but the build-cost of one-off steam locos now closely matches new diesel locos.  Unfortunately, the economics of steam are affected by long periods of inactivity, as the "clock" on a boiler certificate starts counting from the first pressure cycle, so even if you don't use the loco for a year, you've still lost a year's worth of boiler life.  A diesel loco started every month to warm it through and dry off any condensation will, with light maintenance, last almost forever; look at the Class 08.

I would also argue that the infrastructure for running steam locos is greater; while you can have coal deliveries, generally you'll need additional coaling equipment to get it into a bunker or tender and you can't ask the fire brigade to supply water for a whole weekend of steam services, you need a high flow rate water supply installed for topping up.  Meanwhile, a low mileage diesel loco just needs a fuel lorry with industry standard hose connections, to turn up with a few hundred gallons, as required.

I would assume that future steam in the roles I have suggested would be oil or even gas fired, so the infrastructure becomes less of an issue; industry standard fuel or gas lorry to turn up with a few hundred gallons/cubic metres, as required.  I’m not suggesting a whole weekend of steam services, but an occasional use when the power is off for the purpose of working the trains needed to restore it in occupations perhaps after storm or accident damage.  A 100ton tank or two of water would suffice to keep the small loco required to work on site supplied, and it could possibly be delivered to a local railhead on a road low loader while raising steam. 

[Northmoor]

8 hours ago, The Johnster said:

I would assume that future steam in the roles I have suggested would be oil or even gas fired, so the infrastructure becomes less of an issue; industry standard fuel or gas lorry to turn up with a few hundred gallons/cubic metres, as required.  I’m not suggesting a whole weekend of steam services, but an occasional use when the power is off for the purpose of working the trains needed to restore it in occupations perhaps after storm or accident damage.  A 100ton tank or two of water would suffice to keep the small loco required to work on site supplied, and it could possibly be delivered to a local railhead on a road low loader while raising steam. 

Sorry Johnster, I missed that you were referring to gas/oil-fired steam, although the water infrastructure and other issues still apply; you don't need them at all for diesel traction.  Of course if you want a loco for emergency haulage, a diesel still wins as it can be ready to go within minutes of the power going off.  Unless you've had the steam loco on permanent standby with the boiler kept warm by electric heaters (as the DLM rack locos use overnight), you are going to be waiting a long time for the steam loco to be ready.  I think we can all contrive situations where steam will "save the day" - this is the Imaginary Locomotives thread after all, we're allowed flights of fancy - but there is no getting away from the fact that a diesel locomotive is a relatively cheap, reliable, easy to maintain tool.  If we think steam can still be developed further to get closer to the operating efficiencies of diesel or electric, consider that we have barely started with development of diesel-battery hybrids in this country, so steam would be chasing a rapidly moving target.

[rockershovel]

A propos the BR (non) Standard Mallet which appeared a while ago, I found this;

 

 

which gives a pretty good idea of the proportions of such a loco, including the Belpaire firebox! It suggest that a BR version would be a 2-6-6-0 with the boiler reduced to suit ?

[AlfaZagato]

Problem there becomes length, again.   Michael Edge did a scratchbuild  in the 80's posted elsewhere of a supposed Horwich design for an 0-6-6-0, lacking the front pony to accommodate turntables.