Stainless Steel Carriages

[somebody]

Why do all rail networks in this country build carriages out of stainless steel?  You won't see the British, French or Chinese doing so, and if I looked at it long enough, I doubt I would find anyone else who does it except the USA.  Stainless Steel is heavy and results in reduced performance, particularly acceleration.

[Golliwog]

No real idea. Material availability? Because we always have?

[mufreight]

Why do all rail networks in this country build carriages out of stainless steel?  You won't see the British, French or Chinese doing so, and if I looked at it long enough, I doubt I would find anyone else who does it except the USA.  Stainless Steel is heavy and results in reduced performance, particularly acceleration.

I think that you would find that structural strength is a factor coupled with high corrosion resistance and overall apperance, as for the weight factor it is in reality neglible with some of the stainless steels in fact being lighter than a similar strength Corten steel.

[somebody]

What I meant was that most other carriages are constructed out of aluminium, including the TGV, which has never had a fatality on the high speed lines, last I heard at least.

Perhaps there is a federal government mandated standard for stainless steel.

[Zoiks]

Steel has a number of advantages over aluminum. It is more resistance to vibrations, easier to patch etc, can be cheaper etc.

[O_128]

Well the EMUs are 30 years old and perfectly fine, you cant say that for many trains in britain

[somebody]

Well the EMUs are 30 years old and perfectly fine, you cant say that for many trains in britain

I don't think that would be noticed in a discounted cash flow analysis.  Besides, EMUs may be scrapped in the near future anyway.

[Sunbus610]

Well the EMUs are 30 years old and perfectly fine, you cant say that for many trains in britain

Plus there's also Queensland Rail's stainless steel SX sets which were built back in the 1950's (originally for electrification) and which get used on heritage tours,  are still in good shape today.

[HappyTrainGuy]

Well the EMUs are 30 years old and perfectly fine, you cant say that for many trains in britain

Plus there's also Queensland Rail's stainless steel SX sets which were built back in the 1950's (originally for electrification) and which get used on heritage tours,  are still in good shape today.

Not to mention their still getting good use today in other countries.

[colinw]

Yep, still going strong:

In Thailand:


In New Zealand:


Perhaps the most remarkable place to find ex QR equipment 'though, is on the metre gauge Ferrocarril de Antofagasta a Bolivia (FCAB) in South America:
http://www.markusworldwide.ch/Railways/Chile/FCAB/FCAB_Ascotan.htm


Not sure if any SX sets have made it to South America yet 'though.

[SurfRail]

Why do all rail networks in this country build carriages out of stainless steel?  You won't see the British, French or Chinese doing so, and if I looked at it long enough, I doubt I would find anyone else who does it except the USA.  Stainless Steel is heavy and results in reduced performance, particularly acceleration.

You will find our safety standards are considerably higher than most overseas networks - ridiculously higher in fact.  A common benchmark for trains overseas is that they need to be impac resistant at closing crash speeds of 10-15km/hr, here it is much higher.  Aluminium does not comply.

I make no assessment as to whether that is a good thing or not - I'm a lawyer, not a materials scientist or a physicist.

Mind you, stainless steel cars are basically indestructible compared to other types, so have a very long shelf-life - perfect for systems that don't regularly invest in new rollingstock...

[somebody]

That is what I expected.  I think we are getting it wrong.

[O_128]

What part of Thailand do the SX sets run in?, Im going there in September and wouldn't mind riding on one  .

Also I think the oldest train set I saw in the UK was a 1967 stock on the Victoria line and is being phased out by the end of the year so 44 years is the number to beat.

[colinw]

What part of Thailand do the SX sets run in?, Im going there in September and wouldn't mind riding on one  .

I believe they run on the State Railway of Thailand (SRT) "Eastern Line" commuter services from Bangkok to Chachoengsao.  How much longer that will be the case I do not know, as part of the Eastern Line is set to be replaced by an elevated metro line.

[ozbob]

What part of Thailand do the SX sets run in?, Im going there in September and wouldn't mind riding on one  .

I believe they run on the State Railway of Thailand (SRT) "Eastern Line" commuter services from Bangkok to Chachoengsao.  How much longer that will be the case I do not know, as part of the Eastern Line is set to be replaced by an elevated metro line.

Might be needed back here?  LOL

[somebody]

Why do all rail networks in this country build carriages out of stainless steel?  You won't see the British, French or Chinese doing so, and if I looked at it long enough, I doubt I would find anyone else who does it except the USA.  Stainless Steel is heavy and results in reduced performance, particularly acceleration.

You will find our safety standards are considerably higher than most overseas networks - ridiculously higher in fact.  A common benchmark for trains overseas is that they need to be impac resistant at closing crash speeds of 10-15km/hr, here it is much higher.  Aluminium does not comply.

I make no assessment as to whether that is a good thing or not - I'm a lawyer, not a materials scientist or a physicist.

Mind you, stainless steel cars are basically indestructible compared to other types, so have a very long shelf-life - perfect for systems that don't regularly invest in new rollingstock...

Further to my previous comments, I think we will find that HSR is not achievable here without something changing on this front.

[HappyTrainGuy]

Don't the Sweeds have steel hsr carriages... until they damaged a set shunting at a station

[Golliwog]

I can't see having stainless steel HSR making it unaffordable.

[ButFli]

I can't see having stainless steel HSR making it unaffordable.

The requirement of stainless steel carriages is often cited as something that is holding back passenger rail in the USA. Amtrak's Acela really struggled to start with because of the weight of the carriages it had to used. The European system it was based on was aluminium.

[somebody]

The weight adds to axle loads (TGV limits to 17t loaded).  Getting this light loading with heavy bodies isn't likely.  A heavier loading would impact on the track and its maintenance.  Perhaps not insurmountable, but surely adds to the expense.

[Golliwog]

I know it would add to the cost of things, but I can't see steel carriages being what stops HSR in Australia.

[somebody]

I know it would add to the cost of things, but I can't see steel carriages being what stops HSR in Australia.

Agreed.

There is also the large distances involved, well over conventional HSR distances and the political issues.  Third is the crash standards.

[mufreight]

The weight adds to axle loads (TGV limits to 17t loaded).  Getting this light loading with heavy bodies isn't likely.  A heavier loading would impact on the track and its maintenance.  Perhaps not insurmountable, but surely adds to the expense.

The cars built for use on the Southern Aurora and later the Indian Pacific weigh in about 50 tonnes, this gives an axle load of 12.5 tonnes well under your 17 tonne axle load by something like 18 tonnes per carriage which would indicate that Australian rollingstock standards and construction technology might have been leading the pack somewhat. 
It would take quite a bit of traction and control equipment to add another 16 tonnes to a carriage so lets get a bit realistic here and have a little less uninformed conjecture. 

[somebody]

TGV has 2 axles/carriage.

[SurfRail]

TGV has 2 axles/carriage.

2 bogies per carriage, for a total of 4 axles, which gives it a limit of 68t per car.

[somebody]

TGV has 2 axles/carriage.

2 bogies per carriage, for a total of 4 axles, which gives it a limit of 68t per car.

No, my understanding is that 8 carriages have 9 bogies.

[SurfRail]

TGV has 2 axles/carriage.

2 bogies per carriage, for a total of 4 axles, which gives it a limit of 68t per car.

No, my understanding is that 8 carriages have 9 bogies.

Ah, brainfart again - 9 x 17 x 2 = 306 - divided by 8 gives 38.25 per car (excluding driving cars which have their own bogies).  You would be struggling to carry Budd cars on that!

[mufreight]

That being the case that comes in under a 20 tonne axle load so reduce the carriage weight by a further 3.5 tonnes minimum for the fact that the cars only have one bogie the axle loads would border on a maximum of 18 tonnes which with 60kgm rail on concrete sleepers is well under the potential 30 tonne axle loading for such lines and would easily fit into the HSR design envelope for speeds up to 350kph.
Back to the slide rule fellows.

[somebody]

That being the case that comes in under a 20 tonne axle load so reduce the carriage weight by a further 3.5 tonnes minimum for the fact that the cars only have one bogie the axle loads would border on a maximum of 18 tonnes which with 60kgm rail on concrete sleepers is well under the potential 30 tonne axle loading for such lines and would easily fit into the HSR design envelope for speeds up to 350kph.
Back to the slide rule fellows.

Not following what you are trying to say here.  Is it: Why don't we just have 2 bogies/carriage and thus not have to worry about the axle loads?  Well, a possibility, but it does result in a large power consumption and a very heavy load on the ballast in per metre terms.  I am sure that the TGV designers had good reasons to go to such lengths to keep the weight low.

[Golliwog]

I took his point to mean that a bogie is quite heavy, so dropping one off each carriage would drop the per carriage weight a fair bit.

Your comment on the ballast is where the 60kg/m rail and concrete sleepers comes in. IIRC min ballast depth on that is somewhere around 300mm? Either way heavy load on ballast isn't too big a deal. It shatters and every now and then you clean it.

[somebody]

I took his point to mean that a bogie is quite heavy, so dropping one off each carriage would drop the per carriage weight a fair bit.

Your comment on the ballast is where the 60kg/m rail and concrete sleepers comes in. IIRC min ballast depth on that is somewhere around 300mm? Either way heavy load on ballast isn't too big a deal. It shatters and every now and then you clean it.

May not be a big deal at 140km/h, but does that still apply at 300km/h+?

[mufreight]

I took his point to mean that a bogie is quite heavy, so dropping one off each carriage would drop the per carriage weight a fair bit.

Your comment on the ballast is where the 60kg/m rail and concrete sleepers comes in. IIRC min ballast depth on that is somewhere around 300mm? Either way heavy load on ballast isn't too big a deal. It shatters and every now and then you clean it.

May not be a big deal at 140km/h, but does that still apply at 300km/h+?

Very much so and Golliwog you picked up on the point made about the difference between the 17 tonne and the 18tonne axle load and having seen how the stainless steel Southern Aurora cars stood up to the Violet Town collision and more recently when another carriage of the same build over 30 years old being used a a crew car on a PN freight service that derailed in the west I would far prefer steel passenger rollingstock over aluminum despite a minimal weight penalty.

[Golliwog]

I would say theres a bit of a difference between 140km/hr and 300+km/hr but the load being transfered is still the same, it's only the frequency and rate of change of load that would change with speed (though if you have a bumpy ride then higher speeds would mean higher dynamic loads). Rock is more likely to fracture than flow with a faster application of pressure, but even so once you have a few fractures, there are more contacts between each rock which means the pressure at each contact will drop as there are more to spread the load over.