Train of Theseus

[SprinterMan]

For those not familiar with the "Ship of Theseus" Paradox:

Theseus owns and sails a ship. Every month, when he sails to port, he has one old plank of his ship replaced with a brand new plank. By the time 10 years has passed, not a single original plank of wood remains in Theseus’ ship. Is the ship still the same ship?

There is no real "correct" answer to this question, more a matter of opinion. It gets more confusing:

Unbeknownst to Theseus, however, the ship repairman has saved all of the old planks that he removes from Theseus’ ship. Slowly, he constructs a new ship. By the time 10 years has passed, he has acquired every single original plank from Theseus’ ship and arranged them exactly as they were in Theseus’ original ship. Which ship is the original ship?

Again, there is no definitive answer to this. "Why make a thread about this?" I hear you ask. Well, I shall explain:

I was travelling back to university yesterday on the 1508 Birmingham International to Holyhead yesterday. I was on the train for the majority of it's journey, from Birmingham New Street to Bangor (The first and last "places" it serves I like to think, as opposed to an Airport or Ferryport :P ). It left Birmingham as a 4 coach train, with the rear 2 carriages being detached at Shrewsbury.

At Chester, a further 2 carriages were added to the rear of the train, which became the front of the train when it reversed out of Chester. At Llandudno Junction, the rear 2 carriages were detached, and only the front 2 continued to Bangor and Holyhead. This means that no part of the train that left Birmingham 3 hours earlier made it to Bangor or Holyhead (I myself swapped sets in between Colwyn Bay and Llandudno Junction), so made me think that it is a little cheeky (or just damn incorrect) of ATW to advertise it as a through service. What do you people think, should it be advertised as a through service?

On a separate note the 158 that was added at Chester was very sick. I think the brakes were sticking on or something, as it took 3 attempts to pull away from Rhyl and 2 attempts to pull away from Aberegele & Pensarn. The driver applied full power but the train refused to move. There may have been a problem with the door interlock as the door closing alarm sounded between departure attempts at Abergele & Pensarn. On departure from Llanfairfechan the engine of the carriage I was in stopped (whether it stalled or was switched off I don't know; can you even stall something with hydraulic transmission?) and had to be restarted. What was wrong with it I don't know.

Adam

 

[ryan125hst]

I was travelling back to university yesterday on the 1508 Birmingham International to Holyhead yesterday. I was on the train for the majority of it's journey, from Birmingham New Street to Bangor (The first and last "places" it serves I like to think, as opposed to an Airport or Ferryport :P ). It left Birmingham as a 4 coach train, with the rear 2 carriages being detached at Shrewsbury.

At Chester, a further 2 carriages were added to the rear of the train, which became the front of the train when it reversed out of Chester. At Llandudno Junction, the rear 2 carriages were detached, and only the front 2 continued to Bangor and Holyhead. This means that no part of the train that left Birmingham 3 hours earlier made it to Bangor or Holyhead (I myself swapped sets in between Colwyn Bay and Llandudno Junction), so made me think that it is a little cheeky (or just damn incorrect) of ATW to advertise it as a through service. What do you people think, should it be advertised as a through service?

It's interesting that, as Open Train Times doesn't mention any vehicles being detached at Shrewsbury. In addition to this, both Real Time Trains and (more worryingly) National Rail Enquiries don't mention any coaches being attached or detached at all.

Were announcements made about the coaches being attached and detached, and was it clear which coach you needed to be in? It is quite misleading as it could almost be viewed as a change of train, yet there is no mention of this on National Rail Enquiries.

Where did the coaches that were dropped of at Shrewsbury and Llandudno Junction go to after being detached, and where did the ones attached at Chester come from? Did they start/terminate at those locations or did they come from/continue to other places (in public service)?

 

[tbtc]

no part of the train that left Birmingham 3 hours earlier made it to Bangor or Holyhead

That's a very interesting example, and I'm struggling to think of any other routes like this (either now or historically). There are certainly some services which split/ join, but generally they either split *or* join (rather than doing both).

Will put my thinking cap on!

 

[SprinterMan]

It's interesting that, as Open Train Times doesn't mention any vehicles being detached at Shrewsbury. In addition to this, both Real Time Trains and (more worryingly) National Rail Enquiries don't mention any coaches being attached or detached at all.

Were announcements made about the coaches being attached and detached, and was it clear which coach you needed to be in? It is quite misleading as it could almost be viewed as a change of train, yet there is no mention of this on National Rail Enquiries.

Where did the coaches that were dropped of at Shrewsbury and Llandudno Junction go to after being detached, and where did the ones attached at Chester come from? Did they start/terminate at those locations or did they come from/continue to other places (in public service)?

The carriages detached at Shrewsbury returned to Birmingham as part of a later service, and the carriages detached at Llandudno Junction returned to Chester as part of a later service. The screens at New Street said that the rear 2 carriages were being taken off at Shrewsbury, and the guard came through after Chester and told everyone with tickets to beyond LLJ to move into the front set.

That's a very interesting example, and I'm struggling to think of any other routes like this (either now or historically). There are certainly some services which split/ join, but generally they either split *or* join (rather than doing both).

Will put my thinking cap on!

Back in FNW days in 2000, there was a Crewe/Manchester Piccadilly to Holyhead/Llandudno service that joined at Chester and split at Llandudno Junction.

Adam

 

[Welshman]

Train 1D95, the 1625 LLandudno Junction to Chester, is scheduled to arrive in platform 3 at Chester at 1717 [ie before your train from Birmingham].

Train 1D15, the 1508 Birmingham International to Holyhead, is scheduled to arrive in platform 3 at Chester at 1721, therefore on to the rear of the train from Llandudno Junction.

The units then couple up and are scheduled to reverse out of Chester towards Holyhead at 1725.

Therefore, when all is running well, the unit added at Chester is on the rear of the unit from Birmingham, and it is that unit which then detatches at Llandudno Junction. So it is intended that the front unit of the original two units from Birmingham actually reaches Holyhead, and that is the "through" train.

From your account of the extra service being coupled on to the rear of your train at Chester[therefore at the front on reversal], it sounds as though it was late arriving from Llandudno Junction and your Birmingham train had already arrived in platform 3. You say the unit was not in the best of conditions, so that could be the reason it arrived late.

This coupling/uncoupling at Chester and Llandudno Junction is ATW's attempt to provide more accommodation on the busy stretch between Chester and Llandudno Junction at the tea-time rush period. And I think it's a good use of their limited resources.

Incidentally, the relieving unit [the 1625 Llandudno Junction-Chester], is formed from being detatched at Llandudno Junction from the previous 1308 Birmingham International-Holyhead[departing Chester 1522], thus providing extra accommodation on two services from Chester to Llandudno Junction, and returns to Chester by being coupled to the 1832 Llandudno Junction to Shrewsbury [1730 from Holyhead].

This has been happening since the timetable change on 9th December last year.

Incidentallly, I enjoyed your "Ship of Theseus" analogy. It also reminded me of the story of the man who'd had one yard brush all his working life. It had had 15 new handles and 16 new heads, but it was the old faithful brush throughout.

 

[SprinterMan]

Train 1D95, the 1625 LLandudno Junction to Chester, is scheduled to arrive in platform 3 at Chester at 1717 [ie before your train from Birmingham].

Train 1D15, the 1508 Birmingham International to Holyhead, is scheduled to arrive in platform 3 at Chester at 1721, therefore on to the rear of the train from Llandudno Junction.

The units then couple up and are scheduled to reverse out of Chester towards Holyhead at 1725.

Therefore, when all is running well, the unit added at Chester is on the rear of the unit from Birmingham, and it is that unit which then detatches at Llandudno Junction. So it is intended that the front unit of the original two units from Birmingham actually reaches Holyhead, and that is the "through" train.

From your account of the extra service being coupled on to the rear of your train at Chester[therefore at the front on reversal], it sounds as though it was late arriving from Llandudno Junction and your Birmingham train had already arrived in platform 3. You say the unit was not in the best of conditions, so that could be the reason it arrived late.

This coupling/uncoupling at Chester and Llandudno Junction is ATW's attempt to provide more accommodation on the busy stretch between Chester and Llandudno Junction at the tea-time rush period. And I think it's a good use of their limited resources.

Incidentally, the relieving unit [the 1625 Llandudno Junction-Chester], is formed from being detatched at Llandudno Junction from the previous 1308 Birmingham International-Holyhead[departing Chester 1522], thus providing extra accommodation on two services from Chester to Llandudno Junction, and returns to Chester by being coupled to the 1832 Llandudno Junction to Shrewsbury [1730 from Holyhead].

This has been happening since the timetable change on 9th December last year.

Incidentallly, I enjoyed your "Ship of Theseus" analogy. It also reminded me of the story of the man who'd had one yard brush all his working life. It had had 15 new handles and 16 new heads, but it was the old faithful brush throughout.

Hmm, interesting theory, but we actually arrived 5 minutes early into Chester. We then waited a very long time and left late, losing time all the way to Bangor. The unit that was added Chester was the sick one, not the one from Birmingham. I thought that the carriages added at Chester would be added to the Chester end of the train and not the Holyhead end, but the guard assured me that the carriages are always added on the Holyhead end of the train. And the Ship of Theseus paradox is indeed alternatively called the "Trigger's Broom" paradox :P

Adam

 

[Welshman]

Hmm, interesting theory, but we actually arrived 5 minutes early into Chester. We then waited a very long time and left late, losing time all the way to Bangor. The unit that was added Chester was the sick one, not the one from Birmingham. I thought that the carriages added at Chester would be added to the Chester end of the train and not the Holyhead end, but the guard assured me that the carriages are always added on the Holyhead end of the train. And the Ship of Theseus paradox is indeed alternatively called the "Trigger's Broom" paradox :P

Adam

Yes - that's what I was saying. The unit added at Chester was the sick one. The fact you arrived 5 minutes early makes no difference - you had to wait for the unit from Llandudno Junction to be added[as it had lost time by being ailing], instead of it being there waiting for your train to come in behind it. So, regardless of how long you waited at Chester, it was on the front out of Chester rather than the rear, meaning that struggled on to Holyhead rather than the unit you were on from Birmingham.

Regardless of what the guard was saying, check the "Open Trains" site. The unit added at Chester should arrive in platform 3 four minutes before your unit from Birmingham, also using platform 3. So your train should be at the Holyhead end leaving Chester, as they're hardly likely to shunt the unit which has already arrived out at the Crewe end, reverse it back through the middle line and attach it to the Holyhead end.

By the way, I'd heard the story of the one broom many years before John Sullivan gave it to Trig in the "Only Fools" series!

 

[SprinterMan]

Yes - that's what I was saying. The unit added at Chester was the sick one. The fact you arrived 5 minutes early makes no difference - you had to wait for the unit from Llandudno Junction to be added[as it had lost time by being ailing], instead of it being there waiting for your train to come in behind it. So, regardless of how long you waited at Chester, it was on the front out of Chester rather than the rear, meaning that struggled on to Holyhead rather than the unit you were on from Birmingham.

By the way, I'd heard the story of the one broom many years before John Sullivan gave it to Trig in the "Only Fools" series!

Oh right ok, trying to work out what is the "front" of a train that reverses is too hard at this time of night :P

Still, the guard said it was normally done this way, so the lack of through carriages is timetabled if he is correct.

Adam

 

[DarloRich]

For those not familiar with the "Ship of Theseus" Paradox:

There is no real "correct" answer to this question, more a matter of opinion. It gets more confusing:

Again, there is no definitive answer to this. "Why make a thread about this?" I hear you ask. Well, I shall explain:

I was travelling back to university yesterday on the 1508 Birmingham International to Holyhead yesterday. I was on the train for the majority of it's journey, from Birmingham New Street to Bangor (The first and last "places" it serves I like to think, as opposed to an Airport or Ferryport :P ). It left Birmingham as a 4 coach train, with the rear 2 carriages being detached at Shrewsbury.

At Chester, a further 2 carriages were added to the rear of the train, which became the front of the train when it reversed out of Chester. At Llandudno Junction, the rear 2 carriages were detached, and only the front 2 continued to Bangor and Holyhead. This means that no part of the train that left Birmingham 3 hours earlier made it to Bangor or Holyhead (I myself swapped sets in between Colwyn Bay and Llandudno Junction), so made me think that it is a little cheeky (or just damn incorrect) of ATW to advertise it as a through service. What do you people think, should it be advertised as a through service?

On a separate note the 158 that was added at Chester was very sick. I think the brakes were sticking on or something, as it took 3 attempts to pull away from Rhyl and 2 attempts to pull away from Aberegele & Pensarn. The driver applied full power but the train refused to move. There may have been a problem with the door interlock as the door closing alarm sounded between departure attempts at Abergele & Pensarn. On departure from Llanfairfechan the engine of the carriage I was in stopped (whether it stalled or was switched off I don't know; can you even stall something with hydraulic transmission?) and had to be restarted. What was wrong with it I don't know.

Adam

I tihnk you want to stay off the white lightning and the herbal tobacco!

In any event the soul of the train remained constant throughout and was merely passed from vessel to vessel!

 

[SprinterMan]

I tihnk you want to stay off the white lightning and the herbal tobacco!

In any event the soul of the train remained constant throughout and was merely passed from vessel to vessel!

I can assure you that my confusion as to the location of the train's soul does not stem from how drunk or high I am

From your account of the extra service being coupled on to the rear of your train at Chester[therefore at the front on reversal], it sounds as though it was late arriving from Llandudno Junction and your Birmingham train had already arrived in platform 3. You say the unit was not in the best of conditions, so that could be the reason it arrived late.

Looks like you are right, well done This explains why we left Chester so late, although even if it had gotten to Chester on time we still would have gotten there before it as we were early. Probably would have been made to wait at Saltney Junction. This suggests that the guard lied to me that they do this like that, as the timetables show the opposite. Maybe he was trying to hide the fact that the other train was late and unwell, trying to stop Arriva looking bad. Nice to see he cares about their image

Adam

 

[rf_ioliver]

Depends upon the thing you are applying the identity to.

The *identity* of the ship as being "Thesus' Ship" does not change, so from that perspective it is the same ship.

From the point of view of the structure of the ship we have a couple of answers and mathematically we'd say the ship 10 years later is "isomorphic" to the earlier ship (and any during that 10 year time frame). Isomorphic from the Greek: same form.

To define isomorhphism here we are require to decide which properties we are interested in: each ship after each change of wood is the same ship; or at least is indistinguishable in shape, mass, colour (maybe) from any other ship in that time period.

Now if you start looking at other properties such as the physicaly structure of the ship, then the ship isn't the same after each change of plank of wood. Consider what would happen if instead of replacing wood for wood, we replaced wood for, say, plastic.

To answer the question you have to decide to which properties you are identifying the ship by.

Now to go to your train...the identity of the service that runs from Birmingham to Holyhead does not change, but the composition of the units that make up the service do change with the identity of the service being preserved.

Another way of looking at this is if a 2 car 158 ran from Birmingham to Holyhead but its service identity changed at Shrewsbury - is it still the same train?

So, the answer depends upon the structure of the entity to which you are applying an identity.

Hope this helps

t.

Ian

 

[jopsuk]

I was once on a (Virgin) Cross Country service, travelling Edinburgh-St Austell. It was some time ago, so forgive me if the details are a bit blurred, but I'm pretty sure the sequence of events was:

Voyager B was waiting waiting in Waverly for Voyager A, which started in Dundee. The train was thus formed up A-B> (direction of travel).

Somewhere south of York, A was poorly and was detached. Soon after, Voyager C was added to the front, now B-C>. At Plymouth, Voyager B was detached as the train was booked to leave one unit behind. The service thus contunued into Cornwall with just Voyager C.

 

[AlterEgo]

This means that no part of the train that left Birmingham 3 hours earlier made it to Bangor or Holyhead (I myself swapped sets in between Colwyn Bay and Llandudno Junction), so made me think that it is a little cheeky (or just damn incorrect) of ATW to advertise it as a through service. What do you people think, should it be advertised as a through service?

Interesting - does anyone know if this is a regular diagram and not a one-off? I don't think I've been on a service where no coaches that were present when I left were present when I arrived.

It may seem trivial to us but perhaps the disabled, or people who actively book through trains to save moving between trains and carriages might have something to say.

By the way, thanks for reminding me of Theseus' Paradox. I have a friend who collects old Jaguar cars who'd love to hear it, I'm sure!

 

[SprinterMan]

Interesting - does anyone know if this is a regular diagram and not a one-off? I don't think I've been on a service where no coaches that were present when I left were present when I arrived.

It may seem trivial to us but perhaps the disabled, or people who actively book through trains to save moving between trains and carriages might have something to say.

By the way, thanks for reminding me of Theseus' Paradox. I have a friend who collects old Jaguar cars who'd love to hear it, I'm sure!

The guard told me it normally happens like this, but Welshman has proven otherwise with RealTimeTrains (see links in my posts above). The BHM train was early into Chester, whereas the unit that is added was late.

Adam

 

[hilly]

This has happened to me whenever i have caught the holyhead train from cardiff - get to chester to be told you have to change onto a different unit, despite being advertised as a through train. (also on the return 2 units doubled up, advertised as a through train, to then be told to change onto the other unit at chester as both were not going through)

 

[PaxVobiscum]

Would stories about the Sword of Damocles (the point of which is to show that with power comes fear and uncertainty) - as manifested in the East Coast Main Line's Overhead Line Equipment - be off topic here?

 

[SprinterMan]

This has happened to me whenever i have caught the holyhead train from cardiff - get to chester to be told you have to change onto a different unit, despite being advertised as a through train. (also on the return 2 units doubled up, advertised as a through train, to then be told to change onto the other unit at chester as both were not going through)

Indeed, this has also happened to me. 5 car 175 turns up at Shrewsbury with the rear 2 coaches locked out of use. At Chester, the leading 3 cars are detached, leaving the formerly locked out of use unit to continue on to Bangor and Holyhead.

Would stories about the Sword of Damocles (the point of which is to show that with power comes fear and uncertainty) - as manifested in the East Coast Main Line's Overhead Line Equipment - be off topic here?

I was thinking more GEML myself, but that would not be off topic at all. :P

Adam

 

[Welshman]

Depends upon the thing you are applying the identity to.

The *identity* of the ship as being "Thesus' Ship" does not change, so from that perspective it is the same ship.

From the point of view of the structure of the ship we have a couple of answers and mathematically we'd say the ship 10 years later is "isomorphic" to the earlier ship (and any during that 10 year time frame). Isomorphic from the Greek: same form.

To define isomorhphism here we are require to decide which properties we are interested in: each ship after each change of wood is the same ship; or at least is indistinguishable in shape, mass, colour (maybe) from any other ship in that time period.

Now if you start looking at other properties such as the physicaly structure of the ship, then the ship isn't the same after each change of plank of wood. Consider what would happen if instead of replacing wood for wood, we replaced wood for, say, plastic.

To answer the question you have to decide to which properties you are identifying the ship by.

Now to go to your train...the identity of the service that runs from Birmingham to Holyhead does not change, but the composition of the units that make up the service do change with the identity of the service being preserved.

Another way of looking at this is if a 2 car 158 ran from Birmingham to Holyhead but its service identity changed at Shrewsbury - is it still the same train?

So, the answer depends upon the structure of the entity to which you are applying an identity.

Hope this helps

t.

Ian

To think that in my days at theological college we had trouble defining the doctrine of the Trinity!

 

[rf_ioliver]

To think that in my days at theological college we had trouble defining the doctrine of the Trinity!

http://en.wikipedia.org/wiki/Trinity

I'm not surprised!! hock: I'll stick with philosophy and mathematics...

Ian

 

[pendolino]

Depends upon the thing you are applying the identity to.

The *identity* of the ship as being "Thesus' Ship" does not change, so from that perspective it is the same ship.

From the point of view of the structure of the ship we have a couple of answers and mathematically we'd say the ship 10 years later is "isomorphic" to the earlier ship (and any during that 10 year time frame). Isomorphic from the Greek: same form.

To define isomorhphism here we are require to decide which properties we are interested in: each ship after each change of wood is the same ship; or at least is indistinguishable in shape, mass, colour (maybe) from any other ship in that time period.

Now if you start looking at other properties such as the physicaly structure of the ship, then the ship isn't the same after each change of plank of wood. Consider what would happen if instead of replacing wood for wood, we replaced wood for, say, plastic.

To answer the question you have to decide to which properties you are identifying the ship by.

Now to go to your train...the identity of the service that runs from Birmingham to Holyhead does not change, but the composition of the units that make up the service do change with the identity of the service being preserved.

Another way of looking at this is if a 2 car 158 ran from Birmingham to Holyhead but its service identity changed at Shrewsbury - is it still the same train?

So, the answer depends upon the structure of the entity to which you are applying an identity.

Hope this helps

t.

Ian

I like to think that Trigger went through the same thought process with his broom.

 

[swj99]

For those not familiar with the "Ship of Theseus" Paradox:

There is no real "correct" answer to this question, more a matter of opinion. It gets more confusing:

Landrover owners occasionally encounter a similar question from the DVLA about the identity of their vehicles, after significant parts have been replaced. I think the DVLA uses a points system to establish when it ceases to be the original vehicle, and becomes a hybrid, no longer entitled to bear the registration plates of the original.
I remember reading a thread on one of the Landrover forums about it.

Points are allocated for the presence of the original engine, gearbox, rear axle, steering system (factory spec for year of vehicle or different type / upgraded from a newer vehicle) suspension, chassis, etc. But if parts are replaced one at a time, and the original parts thrown away and not used again, I'd say it's still the same vehicle. If a large number of parts were replaced at once, then maybe it is a different vehicle, and perhaps you could apply the same argument to a train or ship. On the other hand, you could also say that as long as the main parts of it are the same, ie, the parts of the vehicle, train or ship which bear it's identifying features, such as a chassis number, name or number plate, then it is still essentially the same, just with some replacement parts. Maybe this is where the saying, 'remove bumpers, fit new car' comes from.

 

[bb21]

That's a very interesting example, and I'm struggling to think of any other routes like this (either now or historically). There are certainly some services which split/ join, but generally they either split *or* join (rather than doing both).

Will put my thinking cap on!

One example I have in my record is from 18th August last year:

185104+185109 left Glasgow Central on 1M94 to Manchester Airport. 185109 was split off at Preston to form 1N94 to Blackpool North (advertised as through train from Glasgow). Meanwhile 185104 was joined at the front by another unit (which I forgot to take the number of) which ran as 1M93 from Edinburgh (advertised as through train to Manchester).

 

[ryan125hst]

One example I have in my record is from 18th August last year:

185104+185109 left Glasgow Central on 1M94 to Manchester Airport. 185109 was split off at Preston to form 1N94 to Blackpool North (advertised as through train from Glasgow). Meanwhile 185104 was joined at the front by another unit (which I forgot to take the number of) which ran as 1M93 from Edinburgh (advertised as through train to Manchester).

Was this during service disruption?

 

[12CSVT]

Landrover owners occasionally encounter a similar question from the DVLA about the identity of their vehicles, after significant parts have been replaced. I think the DVLA uses a points system to establish when it ceases to be the original vehicle, and becomes a hybrid, no longer entitled to bear the registration plates of the original.
I remember reading a thread on one of the Landrover forums about it.

Points are allocated for the presence of the original engine, gearbox, rear axle, steering system (factory spec for year of vehicle or different type / upgraded from a newer vehicle) suspension, chassis, etc. But if parts are replaced one at a time, and the original parts thrown away and not used again, I'd say it's still the same vehicle. If a large number of parts were replaced at once, then maybe it is a different vehicle, and perhaps you could apply the same argument to a train or ship. On the other hand, you could also say that as long as the main parts of it are the same, ie, the parts of the vehicle, train or ship which bear it's identifying features, such as a chassis number, name or number plate, then it is still essentially the same, just with some replacement parts. Maybe this is where the saying, 'remove bumpers, fit new car' comes from.

Could this also be the case with class 47s which have been converted to class 57s ?

 

[krus_aragon]

This has happened to me whenever i have caught the holyhead train from cardiff - get to chester to be told you have to change onto a different unit, despite being advertised as a through train. (also on the return 2 units doubled up, advertised as a through train, to then be told to change onto the other unit at chester as both were not going through)

I find that's more common with the late night diagrams (leaving Cardiff 5pm and later).

 

[Chouette]

Landrover owners occasionally encounter a similar question from the DVLA about the identity of their vehicles, after significant parts have been replaced. I think the DVLA uses a points system to establish when it ceases to be the original vehicle, and becomes a hybrid, no longer entitled to bear the registration plates of the original.
I remember reading a thread on one of the Landrover forums about it.

Points are allocated for the presence of the original engine, gearbox, rear axle, steering system (factory spec for year of vehicle or different type / upgraded from a newer vehicle) suspension, chassis, etc. But if parts are replaced one at a time, and the original parts thrown away and not used again, I'd say it's still the same vehicle. If a large number of parts were replaced at once, then maybe it is a different vehicle, and perhaps you could apply the same argument to a train or ship. On the other hand, you could also say that as long as the main parts of it are the same, ie, the parts of the vehicle, train or ship which bear it's identifying features, such as a chassis number, name or number plate, then it is still essentially the same, just with some replacement parts. Maybe this is where the saying, 'remove bumpers, fit new car' comes from.

It's similar for Windows licensing on PCs as well - if your OS license is OEM and tied to your PC, after how many hardware upgrades does it cease to be the same PC?

Theoretically I believe it's tied to the motherboard, but if that dies and you have to replace it, they will still reactivate it for you...

 

[bb21]

Was this during service disruption?

Not that I remember.