What if APT had been a success ?

[6Gman]

Virgin would be claiming to have introduced them.

No, no - a man with a beard would be claiming to have invented them!

 

[TrainBoy98]

The APT ended up becoming the IC225 (The original name was ATP-U but was changed as APT had such a bad name) so effectivly, APT was eventually a success and still is. I think that what killed the original APT-S fleets from entering service was the fact the power cars were in the centre as it meant everything had to be provided twice and passengers couldnt walk thorugh. Also the fact that they tried to push it into service before it was ready and therefore had problems we and truly put paid to it.

 

[jopsuk]

There's a lot of good technical stuff on traintesting.com

 

[John55]

The APT ended up becoming the IC225 (The original name was ATP-U but was changed as APT had such a bad name) so effectivly, APT was eventually a success and still is. I think that what killed the original APT-S fleets from entering service was the fact the power cars were in the centre as it meant everything had to be provided twice and passengers couldnt walk thorugh. Also the fact that they tried to push it into service before it was ready and therefore had problems we and truly put paid to it.

I struggle to see how the IC225 could be considered any relation of the APT. Could you point out to me any common design feature?

 

[sprinterguy]

I struggle to see how the IC225 could be considered any relation of the APT. Could you point out to me any common design feature?

There’s a few that have been mentioned on this thread already:

Gearboxes mounted in the body and connected to the axles via carden shafts to reduce unsprung weight

Tapered profiles of the Mk IV coaches.

The [production] APT-S trains would have had a streamlined power car at one end and a DVT at the other, sandwiching nine intermediate passenger vehicles. The carriages would, however, have been articulated.

The APT-P was also used, as the train-testing website describes, to test the new high speed Brecknell Willis pantograph to its limits before it was later included in the design of the class 91.

Granted, there is not a direct lineage between the APT and the IC225, development of the latter from the former was more tangential than that. However, the IC225 that was delivered demonstrates in its train formation the achievement of what BR expected from the production APT proposals. As noted above, several of the successful features that were trialled on the APT-P were incorporated into the class 91 and the IC225s, and other features of the 225s incorporated lessons that had been learned from the APT programme: Articulation was dropped, as it would have been on the final APT-U proposal, and steel bodies instead of aluminium were used for the mark 4s to improve the ride quality and reduce vibration. The primary purpose of the APT-P in its’ last couple of years of life was to inform decisions that were made on form that the IC225s would take and to lead the development of these trains.

I struggle to see how you can fail to notice a relationship between the ICC25 and the APT

 

[Yew]

Dont MK4 carriages have a dash of 156 in there too? I seem to remember reading it in wikipedia, but it was on wikipedia...

 

[Waverley125]

on a somewhat related note, I'd absolutely love it if Waterman could restore the surviving APT to mainline running. It'd make a boatload of cash no question.

 

[sprinterguy]

Dont MK4 carriages have a dash of 156 in there too? I seem to remember reading it in wikipedia, but it was on wikipedia...

The form of integral construction is similar in both cases, apparently. Stands to reason given that they are both Metro-Cammell products built at a similar time.

 

[Yew]

on a somewhat related note, I'd absolutely love it if Waterman could restore the surviving APT to mainline running. It'd make a boatload of cash no question.

I wouldnt be so sure, It has quite limited capacity. I fear that unless there are some extra carriages hiding around somehere, it would be hard to make economically viable

 

[John55]

There’s a few that have been mentioned on this thread already:



The APT-P was also used, as the train-testing website describes, to test the new high speed Brecknell Willis pantograph to its limits before it was later included in the design of the class 91.

Granted, there is not a direct lineage between the APT and the IC225, development of the latter from the former was more tangential than that. However, the IC225 that was delivered demonstrates in its train formation the achievement of what BR expected from the production APT proposals. As noted above, several of the successful features that were trialled on the APT-P were incorporated into the class 91 and the IC225s, and other features of the 225s incorporated lessons that had been learned from the APT programme: Articulation was dropped, as it would have been on the final APT-U proposal, and steel bodies instead of aluminium were used for the mark 4s to improve the ride quality and reduce vibration. The primary purpose of the APT-P in its’ last couple of years of life was to inform decisions that were made on form that the IC225s would take and to lead the development of these trains.

I struggle to see how you can fail to notice a relationship between the ICC25 and the APT

My reasoning is quite simple and summarised below in a comparison between the APT concept and IC225

Comparison APT and IC225 coaches

……………...…………………APT…………………IC225

Builder………………………Derby……………….Metro-Cammell
Bogie………………………..BR…………………...SIG
Construction…………....Aluminium……….Steel
Tilt…………………………...yes……………….….no
Brakes………………………hydro-kenetic……friction
Articulation…………..….yes………………..….no

I don't really consider the APT-U as worth discussing as a serious piece of engineering as it was a paper design which did not get built.

It is said that the class 91 locos had some features of the APT power cars but as far as I can tell every important system or sub-system in the loco was a GEC design new for the class 91 or derived from existing GEC equipment supplied on other locos.

The concept of a motor mounted in the body of the loco/power car while not normal in the UK on locos was hardly unknown. After all every BR DMU had body mounted motors driving the axles via a cardan shaft and an axle mounted gearbox. So here is the revolutionary feature - build it like a modernisation plan dmu!

 

[talltim]

I think we would have been moaing about claustrophobic coach interiors and lack of luggage space long before the Voyagers appeared...

 

[D365]

Mk4 tilt? The coaches are designed to tilt, although that option hasn't been taken up. Ironically, the IC250+Mk5 was not, instead running at up to 155mph by means of slewing the WCML [quite significantly].

APT-U did make it into production, albeit in the shape of the somewhat different IC225. I could loosely say the same for the APT-S, as the technology was sold to Fiat Ferroviaria and is incorporated into the 390 Pendolino. (Technology used in development.)

 

[starrymarkb]

I could loosely say the same for the APT-S, as the technology was sold to Fiat Ferroviaria and is incorporated into the 390 Pendolino.

Actually it isn't. UK Pendolinos use the SIG tilt system

 

[sprinterguy]

My reasoning is quite simple and summarised below in a comparison between the APT concept and IC225

Comparison APT and IC225 coaches

……………...…………………APT…………………IC225

Builder………………………Derby……………….Metro-Cammell
Bogie………………………..BR…………………...SIG
Construction…………....Aluminium……….Steel
Tilt…………………………...yes……………….….no
Brakes………………………hydro-kenetic……friction
Articulation…………..….yes………………..….no

I don't really consider the APT-U as worth discussing as a serious piece of engineering as it was a paper design which did not get built.

It is said that the class 91 locos had some features of the APT power cars but as far as I can tell every important system or sub-system in the loco was a GEC design new for the class 91 or derived from existing GEC equipment supplied on other locos.

The concept of a motor mounted in the body of the loco/power car while not normal in the UK on locos was hardly unknown. After all every BR DMU had body mounted motors driving the axles via a cardan shaft and an axle mounted gearbox. So here is the revolutionary feature - build it like a modernisation plan dmu!

The mark 4s were built out of steel because of the ride quality, body flex and internal vibrations that had been experienced with the APT, caused by the aluminium bodyshell and the associated suspension settings.

The mark 4s were built to a tilt profile and with passive provision for a tilt system to be fitted, as while the 225s that were introduced onto the ECML were never intended to tilt, the second batch for the WCML that never came about would have tilted. SIG had their own working tilt system, so I presume that after BR had sold the APTs' homegrown tilt system to the Italians in the eighties then the SIG was a good alternative to provide non-tilt and tilting variants of the bogie for the successor of the APT.

As has already been stated the articulation of the APT had already been dropped during the lie of the APT project due to reasons that have already been mentioned, and it is no surprise that the hyrdo-kinetic brake was not followed up, given it's well publicised problems at the time.

If you are not convinced that a concept on paper is sufficient evidence of BR's proposals for the squadron fleet of APTs then this is a difficult case to argue: The APT-P was only a prototype train, and there was never any promise that the production trains would have bore a great deal of resemblance to it in terms of train formation, as the pre-service trains were intended to test out a number of concepts for potential implementation in the production batch. The proposals for APT-S and APT-U trains demonstrate the evolution of the APT project away from the form of the APT-P trains towards something a bit more conventional, some of the features of which emerged in the 225s.

Though BR tendered out the construction of the 91s and mark 4s to GEC and Metro-Cammell respectively, do you not think that these two contractors would have taken heed of the research and development that BR had already undertaken, or for that matter, that BR would fail to specify the trains to their requirements based on the research that they had already undertaken? I have a book in my possession that was published in 1986 and charts the development of the APT programme and it's activities at the time the book was written. It describes in no uncertain terms that the principal purpose of the remaining APT test runs in the 1984 - 86 period was to aid development of the Intercity 225 (Known as the "Electra" project at the time). If written literature from an author who seems to have had sources within BR is not sufficient evidence, then short of personal experience of being part of the APT team yourself then I don't know what is!

 

[Temple Meads]

I've already asked this question

Original thread here: http://www.railforums.co.uk/showthread.php?t=63551

 

[transmanche]

There's a very good Channel 4 documentary from 1988 about the introduction of the Electra. It's called Running to Time - is and well worth a look.

 

[Manchester77]

If APT has been a success and been introduced to front line service what would have happened to the 86s and 87s? Would some be transferred to freight and used for what 90s do now?
Any thoughts?

 

[ChiefPlanner]

The 90's (or 87/2) would never have been built !

 

[Manchester77]

The 90's (or 87/2) would never have been built !

i dont think i worded it well, sorry

what would the then existing WCML stock been used for?

 

[Bald Rick]

i dont think i worded it well, sorry

what would the then existing WCML stock been used for?

It would have been moved to an electrified MML; that was the original plan.

 

[John55]

The mark 4s were built out of steel because of the ride quality, body flex and internal vibrations that had been experienced with the APT, caused by the aluminium bodyshell and the associated suspension settings.

The mark 4s were built to a tilt profile and with passive provision for a tilt system to be fitted, as while the 225s that were introduced onto the ECML were never intended to tilt, the second batch for the WCML that never came about would have tilted. SIG had their own working tilt system, so I presume that after BR had sold the APTs' homegrown tilt system to the Italians in the eighties then the SIG was a good alternative to provide non-tilt and tilting variants of the bogie for the successor of the APT.

As has already been stated the articulation of the APT had already been dropped during the lie of the APT project due to reasons that have already been mentioned, and it is no surprise that the hyrdo-kinetic brake was not followed up, given it's well publicised problems at the time.

If you are not convinced that a concept on paper is sufficient evidence of BR's proposals for the squadron fleet of APTs then this is a difficult case to argue: The APT-P was only a prototype train, and there was never any promise that the production trains would have bore a great deal of resemblance to it in terms of train formation, as the pre-service trains were intended to test out a number of concepts for potential implementation in the production batch. The proposals for APT-S and APT-U trains demonstrate the evolution of the APT project away from the form of the APT-P trains towards something a bit more conventional, some of the features of which emerged in the 225s.

Though BR tendered out the construction of the 91s and mark 4s to GEC and Metro-Cammell respectively, do you not think that these two contractors would have taken heed of the research and development that BR had already undertaken, or for that matter, that BR would fail to specify the trains to their requirements based on the research that they had already undertaken? I have a book in my possession that was published in 1986 and charts the development of the APT programme and it's activities at the time the book was written. It describes in no uncertain terms that the principal purpose of the remaining APT test runs in the 1984 - 86 period was to aid development of the Intercity 225 (Known as the "Electra" project at the time). If written literature from an author who seems to have had sources within BR is not sufficient evidence, then short of personal experience of being part of the APT team yourself then I don't know what is!

I have read your post above and all is does is confirm what I said earlier, did you really mean that? To summarise your first paragraph the coaches were completely redesigned because the body structure and suspension were seriously short of requirements and the Mk 4 is therefore completely different from APT. Thank you for confirming this.

I have always believed most of the claims that IC225 and APT were closely related were at least partly fabricated because BR and its engineers were too embarrassed to admit they made such a poor fist of the project!

I have worked on major design projects which did not deliver what was required by the market and we had to go away and design something different which we could sell. Its all very embarrassing and you try and pretend it was all worth while because of what you learn and can apply in the future. I have always considered the APT project was much the same.