London to Norwich - 90 min timings

[Railperf]

Getting back to the 755s..we have less than 2 months for them to potentially be used in the Norwich in 90..and yet not a single unit appears to have run the full length of the route in electric mode. How are they doing for type approval and mileage accumulation? And will there be enough time to carry out the driver training?

 

[hexagon789]

The Class 68 driver told me that apart from the initial start..it was on full power and no perceived wheelslip. The 90 run - as noted by another member starts uphill and gets steeper hence the slowing acceleration rate. I have seen a 90 get to 100mph from Ipswich northbound in just over 3 mins and 3.5 miles on a dry rail.
You could spend a day recording these and no two runs would ever be the same. An extra coach or 2 blunts performance - as does a traction motor out. And if it rains - it may never even reach 100mph between some station stops.
That's why the 745's should be better - performance wise. They offer distributed traction - more powered wheels and a consistent performance in wet and dry.

Interesting, I was informed that a 68 was 1 minute quicker to 100 than a 168 - so about 3 mins 15 seconds. I agree with 3 mins to 100 for a 90, that tallies with my expectations.

An 88 is of course more powerful than a 68 by a good margin, perhaps with modern electronics it can best a 90 even with being less powerful.

 

[Railperf]

An 88 is of course more powerful than a 68 by a good margin, perhaps with modern electronics it can best a 90 even with being less powerful.

Could an 88 be spot hired in? Maybe they are not compatible with DVTs

 

[hexagon789]

Could an 88 be spot hired in? Maybe they are not compatible with DVTs

Think they have the unique system fitted to non-Chiltern 68s (which are AAR). The system that the Mk5a stock will use.

Besides, would there be any point?

 

[Railperf]

It's a shame that the maximum speed of the line was not raised to 110mph. At least then, you would have a chance to make up some extra time - especially North of Ipswich. I recall the Class 86 farewell rail tour which ended with a glorious run of just over 82 mins Norwich to London, with speeds over 100mph being the norm for most of the current 100mph sections , 112mph through Diss, 114mph before Stowmarket, 110 through Brantham before 73 at Manningtree, 111 through Kelvedon, 107 at Witham, later reducing speed through and after Chelmsford, but still 95mph before Ingatestone and 99mph between Brentwood and Harold Wood...after that signals started to intervene, and then run-in from Gidea Park was closer to 'normal. And that was an '86' with load 10.

 

[hexagon789]

It's a shame that the maximum speed of the line was not raised to 110mph. At least then, you would have a chance to make up some extra time - especially North of Ipswich. I recall the Class 86 farewell rail tour which ended with a glorious run of just over 82 mins Norwich to London, with speeds over 100mph being the norm for most of the current 100mph sections , 112mph through Diss, 114mph before Stowmarket, 110 through Brantham before 73 at Manningtree, 111 through Kelvedon, 107 at Witham, later reducing speed through and after Chelmsford, but still 95mph before Ingatestone and 99mph between Brentwood and Harold Wood...after that signals started to intervene, and then run-in from Gidea Park was closer to 'normal. And that was an '86' with load 10.

Which subclass of 86? One of the 110mph/5,000hp ones or one of the 100mph/4,040hp ones?

 

[Railperf]

Which subclass of 86? One of the 110mph/5,000hp ones or one of the 100mph/4,040hp ones?

86235 'Crown Point' - I believe that was a 4040bp version. And yes they could easily exceed 100mph, but were not officially allowed to because of the bogie design. The 86/1's were allowed 110mph because they were fitted with Class 87 style bogies if i recall correctly.

 

[hexagon789]

86235 'Crown Point' - I believe that was a 4040bp version. And yes they could easily exceed 100mph, but were not officially allowed to because of the bogie design. The 86/1's were allowed 110mph because they were fitted with Class 87 style bogies if i recall correctly.

Impressive speeds for only just over 4,000 horses and an officially 100mph loco!

 

[Railperf]

Impressive speeds for only just over 4,000 horses and an officially 100mph loco!

Remember an HST only puts down 3740hp at the rail and does 125mph - MAKE THAT 144MPH! , and although it may only have eight trailer coaches compared to 10 for the '86'. it does also have the extra weight of the additional power car to move - so almost another 2 coaches worth!

 

[captainbigun]

86235 'Crown Point' - I believe that was a 4040bp version. And yes they could easily exceed 100mph, but were not officially allowed to because of the bogie design. The 86/1's were allowed 110mph because they were fitted with Class 87 style bogies if i recall correctly.

Not quite. Before the 90s were delivered there was a small pool of 86/2s that were permitted to run at 110mph. Requirements were a Brecknell-Willis high speed pan and increased monitoring of brake blocks. ETL's 86701 and 86702, before export, were both plated for 110mph.

 

[captainbigun]

Impressive speeds for only just over 4,000 horses and an officially 100mph loco!

Don't forget, that's the continuous rating, not the maximum which is 6,100hp.

 

[Railperf]

In the last few years the 86's were knackered - hence the introduction of 90's - but it has taken them a few years to get them running right - as it was claimed that Virgin TraIns had run them into the ground!! It has been 14 years since they were introduced on to the GEML!! Let's hope they get the Stadler units working well a bit quicker than that!

 

[Bald Rick]

It's a shame that the maximum speed of the line was not raised to 110mph. At least then, you would have a chance to make up some extra time - especially North of Ipswich.

A lot of money for very little benefit, particularly north of Ipswich (maximum saving about 100 seconds for non stop trains, less than a minute for anything stopping at Stowmarket and Diss).

 

[Railperf]

A lot of money for very little benefit, particularly north of Ipswich (maximum saving about 100 seconds for non stop trains, less than a minute for anything stopping at Stowmarket and Diss).

The passing time through ipswich was 30.5 minutes. So 31.5 mins for a stopping train would be possible. Plus some additional recovery time for TSR's. But every minute gained here and there helps. The existing timings are quite slack anyway, and don't demand too much from loco or driver.

 

[hexagon789]

Don't forget, that's the continuous rating, not the maximum which is 6,100hp.

Well a 90's maximum is 7,860hp

Remember an HST only puts down 3740hp at the rail and does 125mph - MAKE THAT 144MPH! , and although it may only have eight trailer coaches compared to 10 for the '86'. it does also have the extra weight of the additional power car to move - so almost another 2 coaches worth!

Fair enough, but it is at least geared for higher than 100mph, unless 86s are not specifically geared for just 100?

A lot of money for very little benefit, particularly north of Ipswich (maximum saving about 100 seconds for non stop trains, less than a minute for anything stopping at Stowmarket and Diss).

I think it's been said even raising linespeed to 125 doesn't gain much.

 

[Railperf]

Well a 90's maximum is 7,860hp



Fair enough, but it is at least geared for higher than 100mph, unless 86s are not specifically geared for just 100?



I think it's been said even raising linespeed to 125 doesn't gain much.

A unit such as an 800 that can accelerate to 125mph much quicker than the average 90 to 100mph - would save several minutes. Class 800's for example knock off a minute off HST times due to their superior acceleration. So combine the superior acceleration with 125mph - and it would yield a fair difference - maybe as much as 5 minutes.
But as has been noted on this forum, and I agree - the route isn't deemed worth investing the money in to make this possible. I/E it is not as if you are going to convince people to jump out of their cars instead - who would want to drive from Ipswich or Norwich to London for work? Neither is there a huge market of air passengers that would take the train from Norwich and Ipswich to London instead of flying - to tap in to!!

 

[Bald Rick]

A unit such as an 800 that can accelerate to 125mph much quicker than the average 90 to 100mph - would save several minutes. Class 800's for example knock off a minute off HST times due to their superior acceleration. So combine the superior acceleration with 125mph - and it would yield a fair difference - maybe as much as 5 minutes.
But as has been noted on this forum, and I agree - the route isn't deemed worth investing the money in to make this possible. I/E it is not as if you are going to convince people to jump out of their cars instead - who would want to drive from Ipswich or Norwich to London for work? Neither is there a huge market of air passengers that would take the train from Norwich and Ipswich to London instead of flying - to tap in to!!

There was a report done on this years ago. From memory, on the existing stopping pattern of the slower service, new trains would save 4 minutes Norwich to London on existing infrastructure, and a further 4 minutes if all existing 100mph was upgraded to 110mph and Stratford to Chelmsford was raised to 100mph. Going to 125 saved very little extra, as the trains were stopping so frequently. There is little difference in capital cost between 110mph and 125mph anyway. It does however becomes an issue for maintenance, 125mph track across marshland with lots of heavy container trains are not happy bedfellows.

 

[Esker-pades]

Remember an HST only puts down 3740hp at the rail and does 125mph - MAKE THAT 144MPH! , and although it may only have eight trailer coaches compared to 10 for the '86'. it does also have the extra weight of the additional power car to move - so almost another 2 coaches worth!

Isn't 148mph the record?

 

[Railperf]

Isn't 148mph the record?

Haha, yes indeed, but in my defence i was thinking about the Tyne Tees Pullman Special that hit 144mph with fare paying passengers on board. Wasn't the 148mph HST a test train for the MK4 bogies?

 

[eastdyke]

..... It does however becomes an issue for maintenance, 125mph track across marshland with lots of heavy container trains are not happy bedfellows.

And it would annoy all those pesky marsh dwellers living in their reed huts clustered on islands or raised above the water level on sodden platforms of piled-up sedge and rushes.

 

[Railperf]

Well a 90's maximum is 7,860hp

They never felt like an 8,000hp locomotive. I was shocked at how much better the French BB22500 and BB15000's used to accelerate equally as long or even trains to 100mph much quicker than our 87's and 90's and these were around 5,000hp.
The more powerful 6,300hp Class 91 accelerates slower on a dry rail than even a 90. So it isn't always about horsepower!

 

[Railperf]

And it would annoy all those pesky marsh dwellers living in their reed huts clustered on islands or raised above the water level on sodden platforms of piled-up sedge and rushes.

That 387 I was aboard between Ely and Kings Lynn at a stately 75mph didn't like the state of the track over the fens in places - lurching violently at one point!

 

[dk1]

That 387 I was aboard between Ely and Kings Lynn at a stately 75mph didn't like the state of the track over the fens in places - lurching violently at one point!

It gets a lot worse north, east & west of Ely too. Travel sickness tablets required at times

 

[hexagon789]

They never felt like an 8,000hp locomotive. I was shocked at how much better the French BB22500 and BB15000's used to accelerate equally as long or even trains to 100mph much quicker than our 87's and 90's and these were around 5,000hp.
The more powerful 6,300hp Class 91 accelerates slower on a dry rail than even a 90. So it isn't always about horsepower!

Well I think a 91 is slower because:

1. It's geared for 140 against 110
2. It can only produce a maximum of 6,300hp (6,090hp continuous), a 90 can produce up to 7,860hp while accelerating and that 1,500-odd hp has got to count for something.

Nevertheless, the new Stadlers are going to knock everything for six, if they are even nearly as quick as a Swiss one they'll go like a bat out of hell!

 

[Bald Rick]

That 387 I was aboard between Ely and Kings Lynn at a stately 75mph didn't like the state of the track over the fens in places - lurching violently at one point!

The track up there can go ‘off’ in a matter of hours if the fen misbehaves. It’s an absolute pain keeping it well aligned. There are similar problems (albeit to a lesser extent) in the Diss area.

 

[Railperf]

Well I think a 91 is slower because:

1. It's geared for 140 against 110
2. It can only produce a maximum of 6,300hp (6,090hp continuous), a 90 can produce up to 7,860hp while accelerating and that 1,500-odd hp has got to count for something.

Nevertheless, the new Stadlers are going to knock everything for six, if they are even nearly as quick as a Swiss one they'll go like a bat out of hell!

Yes, the Norwegian type 74 FLIRTs are geared for 200km/h, and they are on a par with a Class 802 for acceleration - 100mph in less than 2 minutes. So even better than 360's and 387's and probably a tad quicker than a class 700. I'm sure I have seen videos of some German FLIRT units getting to 100mph in 90 seconds. That must be pretty spectacular in a train! I reckon the FLIRT's will be a hit.
And if the 720's accelerate as well as the 345's - which can do 0-80mph in a minute - then they too will feel in a different league to what we have now.

 

[eastdyke]

It gets a lot worse north, east & west of Ely too. Travel sickness tablets required at times

Last year's very dry summer would have left the Fenland Internal Drainage Boards struggling with their (water) 'levels'. It May of course be even worse this year

 

[Bald Rick]

Yes, the Norwegian type 74 FLIRTs are geared for 200km/h, and they are on a par with a Class 802 for acceleration - 100mph in less than 2 minutes. So even better than 360's and 387's and probably a tad quicker than a class 700. I'm sure I have seen videos of some German FLIRT units getting to 100mph in 90 seconds. That must be pretty spectacular in a train! I reckon the FLIRT's will be a hit.
And if the 720's accelerate as well as the 345's - which can do 0-80mph in a minute - then they too will feel in a different league to what we have now.

I’ve been on a 700 that reached 100 in the 2m20c from a standing start at West Hampstead to the North Circular. Indeed I suspect we went over 100 as the driver had to brake a bit! I guess that was around 2 minutes.

 

[captainbigun]

Well I think a 91 is slower because:

1. It's geared for 140 against 110
2. It can only produce a maximum of 6,300hp (6,090hp continuous), a 90 can produce up to 7,860hp while accelerating and that 1,500-odd hp has got to count for something.

Nevertheless, the new Stadlers are going to knock everything for six, if they are even nearly as quick as a Swiss one they'll go like a bat out of hell!

Your max rating for the 91 isn’t right, it’s also just under 8k hp.

The acceleration is largely down to gearing which in turn reduces TE at low speed. A 91 will continue to accelerate hard well after a 90 has passed its peak.

 

[dk1]

Last year's very dry summer would have left the Fenland Internal Drainage Boards struggling with their (water) 'levels'. It May of course be even worse this year

The Queen Adelaide 40up & more importantly the 20dn ESRs the latter causing so much disruption have both been removed in the last week but still some very rough spots remaining.