The HST Era continues!

[daikilo]

I wonder how long the chasis will hold out before the metal fractures and rusts and collapses.

There are methods to predict fatigue impacts on maintenance programmes, including the impact of e.g. corrosion.

Personally, I suggest that if the last Valenta-powered HSTs are now being re-engined to MTU it is because soemone has decided they potentially have a few decades of service before them. And I wouldn't be surprised if the early conversions had an engine upgrade before they disappear.

 

[cyclebytrain]

It's certainly possible that there is more fatigue life left in an HST than predicted. As I understand it HSTs are the highest cycle 125mph rail vehicles, so the anticipated fatigue life will be based solely on theoretical mathematical modelling, supplemented by destructive testing of parts taken off an HST that has been in service. But there is no equivalent that has a higher number of cycles that experience can be drawn from.

The converse of this is that the fatigue life may be less than calculated, in which case it'll probably be discovered when the first one falls apart (obviously this depends on how conservative the initial model was).

It's probably also worth noting that the engine change will have changed the vibration loading and there may be some surprises there.

 

[starrymarkb]

There are methods to predict fatigue impacts on maintenance programmes, including the impact of e.g. corrosion.

Personally, I suggest that if the last Valenta-powered HSTs are now being re-engined to MTU it is because soemone has decided they potentially have a few decades of service before them. And I wouldn't be surprised if the early conversions had an engine upgrade before they disappear.

IIRC the FGW refits were done with a life expectancy of 10 years (which would have taken them through to the planned IEP delivery dates with a year or two to spare)

 

[daikilo]

It's certainly possible that there is more fatigue life left in an HST than predicted. As I understand it HSTs are the highest cycle 125mph rail vehicles, so the anticipated fatigue life will be based solely on theoretical mathematical modelling, supplemented by destructive testing of parts taken off an HST that has been in service. But there is no equivalent that has a higher number of cycles that experience can be drawn from.

The converse of this is that the fatigue life may be less than calculated, in which case it'll probably be discovered when the first one falls apart (obviously this depends on how conservative the initial model was).

It's probably also worth noting that the engine change will have changed the vibration loading and there may be some surprises there.

Fatigue life modelling is now very scientific. A single failure is not a critical unless it is outside the scope of predicted concerns, but it may be a warning. That the HSTs may be moving toward the limit of factual knowledge in itself is not an issue if modelling has moved on and that the techniques and assumptions are validated.

 

[cyclebytrain]

Fatigue life modelling is now very scientific. A single failure is not a critical unless it is outside the scope of predicted concerns, but it may be a warning. That the HSTs may be moving toward the limit of factual knowledge in itself is not an issue if modelling has moved on and that the techniques and assumptions are validated.

You are very optimistic. A 2002 round robin of rotary wing companies (on fatigue) produced rather varying results (the worst was over 40 times the actual failure time of a tested sample). And people still wonder why I stay away from fatigue problems as much as I can...

 

[yorkie]

Much better passenger environment for anal rail entusiasts. I'd like to make people aware that post refurb, Mallard seats do not always align with windows. Also, I like my knees to not be wedged into the chair infront like in the Mallard refurbishment.

You must be very tall then! I recommend you try to get a Priority seat next time. EC publish a seating diagram on their website. According to that, it's the low number seats to go for (I'd have to check but, from memory, that seems right).

 

[Templecombe]

your talking nonsense

No I'm not