General railway discussions

[crs1026]

Galvanic corrosion is a well enough known phenomenon that it doesn't really enter into the equation as a "gotcha!" for railway equipment anymore. Hell, even the 1954-built CC&F and Budd cars had steps and processes to their construction and assembly to mitigate against it quite effectively.

Dan

Fair enough, but that corrosion has still caught up with equipment of that vintage - albeit slowly - and one would expect it to be a consideration for inspections of any aging equipment. The assertion that corrosion isn't a consideration for aluminium or stainless steel is simplistic.

At the end of the day, we don't yet know enough from Amtrak about where the Horizon corrosion is or what it is from. Or how many one-ofs were identified and known previously before the call to inspect the entire fleet.

Rust never sleeps.

- Paul

 

[urbancog]

stainless steel is corrosion resistant, not corrosion proof

Many moons ago I lived next to a Rolls Royce Aeroengines metallurgist, he said it should be referred to as stain-less steel.

 

[smallspy]

Fair enough, but that corrosion has still caught up with equipment of that vintage - albeit slowly - and one would expect it to be a consideration for inspections of any aging equipment. The assertion that corrosion isn't a consideration for aluminium or stainless steel is simplistic.

At the end of the day, we don't yet know enough from Amtrak about where the Horizon corrosion is or what it is from. Or how many one-ofs were identified and known previously before the call to inspect the entire fleet.

Rust never sleeps.

- Paul

Sure, but galvanic corrosion is not the same as the normal time-based corrosion process that many metals go through. And in the case of aluminum, much like stainless (or stain-less, if you so prefer) it almost doesn't apply.

What does apply, and especially in the case of aluminum, is fatigue.

Dan

 

[nfitz]

I'm not sure what the corrosion issue is then. Just a leaking roof? Just change seats, like you used to have to do in a CLRV when it rained.

 

[Bordercollie]

Sure, but galvanic corrosion is not the same as the normal time-based corrosion process that many metals go through. And in the case of aluminum, much like stainless (or stain-less, if you so prefer) it almost doesn't apply.

What does apply, and especially in the case of aluminum, is fatigue.

Dan

So would older comet cars be subject to the same issue?

 

[Allandale25]

 

[smallspy]

I'm not sure what the corrosion issue is then. Just a leaking roof? Just change seats, like you used to have to do in a CLRV when it rained.

I'm not sure what the issue is, to be honest.

There may be corrosion of the steel components as they are bolted onto the aluminum structure, meaning that they could be in theory replaceable. And as the design was built for a 25 year lifespan, and they are far past that, it may be that they are in need of a large structural refurbishment program.

But there may also be fatigue of the aluminum body as well. I suspect that the stresses that the cars go under are a bit different than the stresses that a commuter car would see in its lifetime. Many of the same, but some different ones.

Another thing to consider is all of the additional equipment that the cars have as part of being in a long-distance passenger service versus commuter service. Upgraded HVAC, upgraded electrical capacity, heavier trucks.....all of that heavier equipment may have an adverse affect, too.

But in short......I don't know.

Dan

 

[Sauga89]

So would older comet cars be subject to the same issue?

I'm not sure what the issue is, to be honest.

There may be corrosion of the steel components as they are bolted onto the aluminum structure, meaning that they could be in theory replaceable. And as the design was built for a 25 year lifespan, and they are far past that, it may be that they are in need of a large structural refurbishment program.

But there may also be fatigue of the aluminum body as well. I suspect that the stresses that the cars go under are a bit different than the stresses that a commuter car would see in its lifetime. Many of the same, but some different ones.

Another thing to consider is all of the additional equipment that the cars have as part of being in a long-distance passenger service versus commuter service. Upgraded HVAC, upgraded electrical capacity, heavier trucks.....all of that heavier equipment may have an adverse affect, too.

But in short......I don't know.

Dan

I'm not sure if this helps since it isn't a corrosion issue per se, but I occasionally read the forums at amtraktrains.com and someone there mentioned an issue Metro-North had in 2009 with its Shoreliner cars (a very similar model of the same vintage as the Horizons), which apparently required additional bracing. I went hunting for what he meant and I think I found it.

From The Rail Engineer Magazine October 2011 pg 38.

"In January 2009, an axle fracture occurred on a Shoreliner coach. The incident led to only a minor service disruption, but analysis of the fracture indicated that it was caused by higher than normal cyclic stresses which developed in the axle due to the presence of a severe flat in the tread of the wheel. It is estimated that the life of the axle under these circumstances could only be 3 to 8 days.

Maybe corrosion is causing the axles to fail?

 

[crs1026]

Considering that none of us have actual details, it's probably enough to recognize that stuff happens to old equipment, and that is playing out here in some fashion.

The question that Amtrak will face is - how prevalent is the problem, and is it something that is inevitable across the fleet. And if so, can it be corrected or remediated - and at what cost.

The issue is probably beyond any warranty or legal redress, even if testing points to a historical manufacturing or material problem. So Amtrak will have to decide if it can afford to repair the cars, or replace them..... or take the hit and delete them from the fleet without replacement. In the current governmental turmoil, money may be hard to find.... but Amtrak is proceeding with other procurements that may mitigate the whole problem to some degree.

One wonders how such problems come as a surprise (it may not have been a surprise internally, although its rate of growth might make it seem as such.) if proper life cycle oversight is happening. But on this continent, the political acceptance that things wear out and need replacement is not there... as we see with VIA's fleet, TTC subway cars, etc etc.

Guess what - the Ventures will wear out one day also.

- Paul

 

[crs1026]

I'm not sure what the corrosion issue is then. Just a leaking roof? Just change seats, like you used to have to do in a CLRV when it rained.

The Amtrak problem doesn't sound like a leaky roof issue - but to digress as a further bit of case study trivia for those who think of Budd stainless cars as eternally indestructible.....

The Budd product was constructed by bending and folding raw strips of stainless steel and then spot-welding the assembly into more solid components.

Spot welding joins the metal at multiple specific spots... but is not a continuous weld that seals every strip to each other continuously. There are seams that may lose their seal as the cars pound out their millions of miles.

Operators such as VIA have dealt with this by applying a rubberish undercoating that seals the cracks.... but that undercoating doesn't last forever. So yes, the roofs and joints around vents etc do leak eventually. And (as any homeowner knows) water once inside a roof may take a tortuous route before it comes out of the ceiling. Good luck figuring out where the leak is ! It may take a substantial teardown to find and fix the problem. Leaving the water in place leads to mould, corrosion of interior components, etc. so isn't advisable.

The point being, this is one small example of how stainless steel cars (and those beloved RDCs) don't last forever, and the work involved in full life extensions gets costly, and yes it's more likely that an operator will buy new rather than rebuilding one more time.

- Paul

 

[Bordercollie]

I'm not sure if this helps since it isn't a corrosion issue per se, but I occasionally read the forums at amtraktrains.com and someone there mentioned an issue Metro-North had in 2009 with its Shoreliner cars (a very similar model of the same vintage as the Horizons), which apparently required additional bracing. I went hunting for what he meant and I think I found it.

From The Rail Engineer Magazine October 2011 pg 38.

Maybe corrosion is causing the axles to fail?

That's an easy fix. Order new axles. If it's something like the truck assembly, that's more difficult.

 

[smallspy]

I'm not sure if this helps since it isn't a corrosion issue per se, but I occasionally read the forums at amtraktrains.com and someone there mentioned an issue Metro-North had in 2009 with its Shoreliner cars (a very similar model of the same vintage as the Horizons), which apparently required additional bracing. I went hunting for what he meant and I think I found it.

From The Rail Engineer Magazine October 2011 pg 38.

Maybe corrosion is causing the axles to fail?

The trucks under the Horizon cars are entirely different than the ones under the Comet and Shoreliner cars. Comet cars use inside-bearing trucks where the Horizon cars use a GSI outside-bearing truck. In fact, the trucks are the same as used on Amtrak's Superliners and Viewliner cars, but with different springs and dampeners.

While there could be a wheel or axle issue with the Horizon cars (it's unlikely for a number of reasons), it wouldn't be this specific wheel or axle issue.

Dan

 

[Sauga89]

The trucks under the Horizon cars are entirely different than the ones under the Comet and Shoreliner cars. Comet cars use inside-bearing trucks where the Horizon cars use a GSI outside-bearing truck. In fact, the trucks are the same as used on Amtrak's Superliners and Viewliner cars, but with different springs and dampeners.

While there could be a wheel or axle issue with the Horizon cars (it's unlikely for a number of reasons), it wouldn't be this specific wheel or axle issue.

Dan

My apologies then for bringing it up, and thank you for a good answer.

 

[dowlingm]

The discussion re Horizons on railroad.net mentions coach steps a number of times as being subject to un-remediated corrosion. Is it possible these are steel construction?

In any case, we see once again the consequences of “lean” practices colliding with insufficient industrial and capital capacity, which means thanks to previous issues like unplanned Talgo withdrawal, other than ancient Amfleets and the like there are little if any spare coaches to fill these gaps, which in turn is leading to capacity reductions and cancellations, just as we see LRCs continuing to be desperately needed up here on corridor and the LD fleet being stretched through lack of certain coach types.

 

[smallspy]

The discussion re Horizons on railroad.net mentions coach steps a number of times as being subject to un-remediated corrosion. Is it possible these are steel construction?

The steps on the Horizon cars are stainless steel components that are bolted to the carbody. They are designed to be a replaceable part, and have in fact already been replaced at least once in the Horizon's lifetimes.

Dan