Steam locomotive more technologically advanced than modern airliners for its time?

I think the steam locomotive was far more technologically advanced for its time than any jet airliner is today.

Even looking at an A1 Pacific there is far more to it than the jet engine. The jet engine is relatively simple, fans that get smaller as the force air into a narrow appeture to combust it. Attached to wings a body and tail.

The steam engine is far more complex than that. Fire tubes, superheater elements , firebox stays. Even the complex shaping of the firebox end and boiler barrel that holds immense pressure, a pressure able to pull hundreds of tonnes of freight. All manner of steam pipes and tubes, water injectors, lubricators. Accurately timed valves and Walcherts valve gear that to this day I have difficulty understanding.

So is the Steam locomotive far ahead of its time compared to airliners?

I think you may be confusing the issue. The steam engine like the jet engine is just one part of the vehicle. If you take the number of parts for the steam engine on its own, it pales into insignificance with the pieces of a jet engine surely. The fuel and management system of the steam engine also has fewer parts than the fuel and management system of the jet engine (Unless you are talking about a V1 rocket motor). As for the steam loco being more advanced for its time, then that has some merit for debate.
BobH

Are we comparing apples with apples? Are we comparing airliners with a steam engine, or just the jet engine with a whole locomotive?

I'm not sure I would call an A1 Pacific "advanced" when it was little different from a locomotive built 100 years before. Larger size, different valve gear, higher pressures, piston valves, injectors and mechanical lubrication were all incremental changes to a basic design that went at least as far back as the Planets, if not Rocket itself. The gas turbine, like the steam turbine before it, was a complete technological leap in performance, materials and manufacture away from the reciprocating engines that it replaced.

As far as "for its time" goes, the interval between the Pen-y-Darren locomotive and the GWR Iron Duke class is similar to that between the Wright Flyer and the DC-3.

Brian

Edited By Brian G on 14/02/2018 17:23:52

I recently visited Didcot and was struck by how basic steam locomotives are, - probably part of their appeal. Also I suspect much of the design work was by rule of thumb and trial and error. A single engineer (highly skilled) could have designed a steam loco, - could a single person design a modern jet? I doubt it.

Mostly Sir Frank Whittle so I don't doubt it at all

I suggest it's a misunderstanding to think that jet engines are simple. Although the principle of driving a fan with exhaust gas might be easy enough, it's much harder to build a working engine. And another series of difficult development challenges to make it lightweight, efficient, maintainable and reliable. Hundreds of tough problems have to be solved, for example:

• For efficiency reasons combustion should take place at the highest possible temperature. Not far below the boiling point of steel. So the combustion chamber and blades at the hot end of the engine need to be made of something special, with special arrangements to keep them cool.
• The blades and ducting inside the engine are aerodynamic. The profile of the blades is critical in 3 dimensions and blade shapes and sizes are different at each stage of the engine.
• Most materials soften when heated. A turbine blade is not only very hot, but it spins at several thousand rpm. Centrifugal forces on the blade are high. The blade has to be constructed so that it doesn't stretch or break under demanding operational conditions. Not only that, but because blades have to be replaced, you have to find a way safe way of attaching them to the spindle that allows speedy maintenance.
• Again for efficiency it's important that the gap between blade tips and the ducting be kept as small as possible. That means turbine blades mustn't stretch or expand with temperature. If they do the engine will explode.
• The engine has to survive hitting a large bird at high speed
• One way of making turbine blades is to grow them as a single crystal from an ultra-pure Nickel Super-Alloy. Not easy!
• The maths is challenging too. For example, how much air do you have to compress at 3000m to maintain an output of 1MW? And how much power is needed to drive the compressor? How big does the combustion chamber need to be? How many stages, how many blades?
• Having solved the maths, how do you then design the compressor needed to deliver the right amount of air when the engine is taxiing on the ground, and accelerating down the runway, and climbing to operating height, and as it cruises? Whatever you come up will have to be a clever compromise.
• Clever compromises feature throughout the engine. It has to be strong and lightweight. It has to be solidly built and easy to maintain. It has to run as hot and fast as possible without breaking or catching fire. It has to safe and affordable.

Back in the day, steam engines presented equivalent difficulties. Early on much of the science was poorly understood, materials undeveloped, skills rare and technology primitive. Technology doesn't stand still and by 1920 the steam locomotive was pretty much as good as it could be. After 1920 only small improvements to steam reciprocating engines were left to do. Although steam was done, the technologies and benefits it had sparked continued.

I say that the steam engine is father to most modern technology. Although the Victorians couldn't build a jet engine, much of what we know and do is built on their foundations. If they hadn't done what they did, we wouldn't be making jet engines either.

Dave

Hi Simon,

Not sure this is the best forum for your question. Have you come across NatPress?

Some poor sod in LNER and BR days was paid a pittance to shovel tons of coal into an A1 firebox getting backache and blister on his hands, scorched legs, and covered in coal dust. The same poor sod had to work the injectors and keep a watch on the water gauges on a draughty cab. He would have to get up at all hours of the day and night on shiftwork and was not paid enough to own a car so would walk or cycle to work in all weathers probably from a small terraced house or council house.

Some other poor sod had to shovel out a smokebox of ash, and empty the firebox of clinker, if the fireman was lucky not to have to do this also. No covered accommodation for this - the wind would blow everything all over you and if it was raining you got soaked.

The fireman would have to go down and couple up the coaches or goods vehicles to the loco/tender which was precarious and risky and also very dirty.

Long shifts at unsocial hours, and to no set pattern.

Then you get a poor loco long overdue for a shopping that shakes you to bits and gives a very rough ride and steams poorly and you spend your whole shift in discomfort and struggling to make steam.

You finish your shift filthy dirty and your home does not have a modern bathroom, neither do you have facilities at work to wash and change before going home.

(Suggest you read Harold Gasson's books)

Cheers,

Julian

You have got to be kidding. A 747 has six million parts, almost 200 miles of wire and five miles of tubing.

The cabin pressurising and air conditoning system alone is more hi-tech than any steam train ever made. Let alone all the stuff in the cockpit control panel and the systems it links to.

Groups of local enthusiastic amateurs regularly restore and run steam trains. I can't see them getting an old 747 off the ground and keeping it there in 50 years time. (Yes there are guys who restore WW2 planes, but most of them are ticketed aircraft engineers, and they are not working on 747s).

Wasn't / isn't each form developed as highly as technology and accountancy allowed in its day to be as efficient and reliable as possible. Steam reached the end of its road when diesel and electric was deemed a better option and we have to assume the jet engine will be superceded at some point too.

Hi Julian

Sixty years ago I was a steam loco driver.

I enjoyed every moment of it and I bitterly regret that I am now too old to drive as a volunteer.

I never objected to getting up at all odd hours and, if it was possible I would go back to firing and driving right now!

Why were there so many youngsters who would give anything to climb on board a "King" or "Castle" knowing that they had years of cleaning and firing before they grabbed hold of that beautiful handle and felt her get hold of the load.

Every job has some disadvantages and firing and driving steam locos no more than any other.

Were you a driver?

Richard.

I think Julian has point, but it is amusing how many people spend large amounts of time and money to recreate that experience in miniature

I think the original question misses a key point.

At any time and place in human history something is the cutting edge technology. Even stone axes. At one time it was the steam engine. For a brief period in Victorian times it may have been the electric car. During the first World War it was almost certainly aircraft. At other times many things compete - in WW2 radar, the emerging jet turbines, computing.

The term 'ahead of its time' is often mis-used too. It doesn't really mean 'this is something from the future', it means 'this technology failed because materials or other supporting technologies weren't up to supporting its development or implementation'.

The gas turbine is interesting because its principles were well understood in the 19th century, but the applications were limited by the materials available. The much lower demands on metallurgy of steam engines allowed their greater refinement and spread.

Neil

This does raise the interesting question of how do you define technically advanced.

I would suggest it is not the same as complexity which would correllate strongly to the componant count.

Perhaps a helpful guide would be how the hardware 'manages' the particular physics involved in the device.

To take the example suggested of the Steam engine and the Jet engine the physics would be largely Thermochemistry (combustion) Thermodynamics (energy transfer) and Fluid dynamics (gas flow).

On this basis the steam engine having a less well developed theoretical model on all three counts than the Jet engine should be more technically advanced assuming that a closer understanding of what is actually going on with the physics allows a closer approach to an ideal design.

Simplicity does not per se equate to technical primitiveness. Jet nozzles can now be developed extremely precisely using finite element anlysis, something that was not possible when designing steam injectors for example. That said with modern computer modeling it should be possible to design a more technically advanced steam engine than anything that was around in the past. Maybe a new category for a Model Show Trophy?

So yes I would say the Jet engine is more technically advanced than the steam engine.

regards Martin

Was the steam loco as cutting edge technology in the 1920's as an aircraft is now?

No.

By the 1920's steam engines were old hat and had significantly failed to improve efficiency, running costs and improve design life. Look at Chapelon's and Porta's work on developing steam technology. They did nothing that was not possible in the 1920's using 1920's knowledge, theory and equipment. Porta in particular took a 1920's steam loco and made it more efficient and cheaper to run than a diesel for 10 years in the 1980's, keeping a coal mine in Argentina viable. The fact that the work was not done in the 1920's speaks volumes of how far back locos were from the cutting edge. Porta's work really emphasised the inefficiencies and poor design in steam locos that were there all the time.

In the 1920's an aeroplane was the cutting edge technology. Aircraft still are cutting edge technology because of the pressure of the fact an aircraft is such a phenomenally expensive bit of kit to run and in a hugely competitive industry. If 1% can be shaved off the fuel consumption or manufacturing cost, it's a major cost saving. If a part can be made lighter, it can contribute to fuel saving. If a bit can be made more reliable and lighter, even better. If it can be made lighter, cheaper & more reliable everyone wins. That's what's driving 3D printing in aircraft bits, and is as 'forefront of technology' as you can get. In the 1920's there was the same drive to get bigger aircraft, increase range, more passengers, fewer deaths. The forefront of technology at the time was in petrol engines and the conversion from wood to the new wonder material, aluminium. All happened in aircraft, not locos. The developments in locos in the 1920's were brute force & ignorance developments, more power, more fuel & more pressure. There was no finesse in the understanding & application of the engineering.

Regards,

Richard.

The difference between a B 747 and a B787 is almost as great as the difference between a DC-3 and the B 747, yet the B-52 bomber designed in the early 50s is expected to out last it's successors, the B-1, and B-2 and continue in service until at least 2050, a case of best for service.

Ian S C

Not on topic but why do people consistently refer to 'jets' and 'jet aircraft' when they mean gas turbine powered aircraft. We don't refer to similarly powered warships or power stations!! I could see the aeolipile or Hero's steam engine as jets or, at a stretch, the Fairey Rotadyne. Maybe one should refer to Spitfires, Hurricanes et al as 'props'

rgds

Bill

The Fairey Rotadyne units were of course RamJets with no moving parts like fans and compressors. Also **** noisy.

Perhaps because jet aircraft are jet propelled in the same way as a jet-ski or a squid, by reaction to a jet of their working gas or fluid. Describing aircraft as gas turbine would lead to confusion as there are turbojet (747), turboprop (Viscount) and turboshaft (helicopter) gas turbines.

Brian

The same applied to the internal combustion engine in the early 20th century. All the exotic stuff we take for granted today like super high compression ratios, high rpm engines, desmo valves, overhead cam, etc etc were all known about and used experimentally in the 1920s, but it was the state of the metallurgy that stopped them going mainstream until after WW2, when great advances in metallurgy were made.

Even steam turbines required exotic metallurgy back in steam engine days. There is a sugar mill near where I live (well about 800 miles away, close enough) at Bundaberg that is still powered by reciprocating horizontal steam engines -- built and installed in 1948 because Australia didn't have the metallurgy to build steam turbines and post-war austerity measures forbade the import of turbines from overseas at that time. But they did have a local locomotive manufacturing works that could turn its hand to mill engines if need be. How cool is that?

Don't see too many loco's of any sort flying about.

Regards

Lofty