Fastest Accelerating MUs in the UK

[Energy]

The 755 will soon pass it even if it does accelerate any faster as it will crawl along at 75mph.

Yeah, they are designed for frequent stops though so the acceleration is more important.

Correction, 777s will be the same acceleration as the 755/4s on electric (1.1m/s) looking at the 755 document and 777 document from Stadler.

 

[dk1]

Yeah, they are designed for frequent stops though so the acceleration is more important.

Correction, 777s will be the same acceleration as the 755/4s on electric (1.1m/s) looking at the 755 document and 777 document from Stadler.

Ahh so the 755/3 will top it. They really are hot stuff.

 

[100andthirty]

The Stadler documents need careful reading. For class 777, they quote starting acceleration, for class 755 they quote mean acceleration. The two are not the same and as others have said, in the end it's power that matters, and a class 755 has 1MW more installed power than the class 777. I am confident that class 777 will be absolutely suitable for its duty, but the class 755, especially as the three car, is something special when on electric power. It makes up for the deficit on diesel power compared with the 4-car sets.

 

[rebmcr]

Thing is about the 755/3 is the acceleration does not peter out as drag increases due to speed. As we know drag squares with speed but the acceleration of a 755/3 on the wires just doesn’t seem to die out all the way to 100mph. They just keep accelerating with seemingly little impedance all the way to 100mph

That means the limiting factor is rail adhesion rather than available power.

 

[delticdave]

As you might expect from my username, I was (still am) an enthusiast of the 309s but am aware that no MKI EMUs stand direct comparison with even MKIII types as the power to weight ratios were much more modest in the '60s. The 321s had ratios of 7.7kW/tonne whereas the 309/2&3 class did their thing on just 4.9kW/tonne. They were also the only MKI EMUs geared for 100mph.* That is unless the REP 'tractor' units were counted, (12.5kW/tonne) because they never ran in passenger service without some deadweight 'TCs in tow. That would be like comparing the 309/1 2-car units in isolation (although they did often run alone between Thorpe le Soken and Walton-on-the-Naze), but that stretch of track was no speed-test strip. Their 8.4kW/tonne - would however have made them pretty snappy up to speed on the GEML.
* The 432s were geared for 90mph although there are many, (maybe apochryphal) reports -some on RUK, of wild speeds in excess of 100mph being logged. A 309 consist did actually acheive 109mph on some high speed test runs with frontal streamlining over a fast section of the WCML near Cheddington but their genuine 100mph gearing with less than 5kW/tonne and their 0.9mph/sec/sec rate was never going to make them rapid accelerators.

Interestingly, when the class 312s were introduced, their 90mph maximum speed was questioned, but it was explained that their faster acceleration (1.1mph/sec/sec) enabled them to slot into the faster ICs running both on the GEML, ECML and parts and the West Midlands LMR network, (much like the class 700's 100mph maximum is mitigated by their acceleration on the MML fasts).

Did you travel on the 309 excursion from Euston to Wolverhampton, Walsall, Altrincham & Hadfield some years back?

I was riding in the front coach on the return trip & could see the speedometer through the (closed) gangway door, it did indicate 100 mph somewhere between Bletchley & Watford. Apart from the unusual routing, the most memorable moment was when I left the train at Euston, we were met by the BTC police & their dogs. They had been told to meet a "special train" & had assumed that we were football fans...... They then decided that a crowd of blokes with cameras, all taking the same shots of the train, it's special head-board & the train-crew, didn't really require their presence....

DC

 

[Railperf]

Yeah, they are designed for frequent stops though so the acceleration is more important.

Correction, 777s will be the same acceleration as the 755/4s on electric (1.1m/s) looking at the 755 document and 777 document from Stadler.

So with regards to what we’ve seen so far is there anything that can pip a 755/3 on juice? 27 seconds to 60 is ludicrous. 710 31 seconds, I assume a 345 would be just behind them, having a trailer in the middle does them no favours. Anything else?

In my book, here is the shortlist:
1. 755/3 0-60mph in 27s 0-90mph in 56s, 0-100mph in 69s (electric mode)
2. 755/4 0-60mph in 32s 0-90mph in 66s and 0-100mph in 85s (electric mode)
3. Tie between 345 & 710 Both do 0 to 40mph in 18s, 50mph in 25s.
I haven't recorded a 710 beyond 50mph, but the 345 FLU went on on to reach 60mph in 34s and 90mph in 73s, So i'm guessing the 710 could be pretty similar.

EDIT:4. Class 745/1 0-60mph in 38s - 0-90mph in 80s, 0-100mph in 103s - fastest 100mph Intercity unit?

5. Class 331. 0-60 in 34s - 0-90mph in 82s , 100mph in 110s. (Quick to 60mph) but tailing off power wise to 90 and 100mph
6. Class 395 Javelin 0-60mph in 36 seconds.

Fastest diesel: 755/4 0-60mph in 49 seconds, 0-90mph in 107s 0-100mph in 147s.
Slowest diesel I have recorded HSt 2+8 set on one power car. 0-60mph in 201s. 0-100mph in 847s.

 

[gimmea50anyday]

802's are slow on diesel.. Not worth a mention compared to the 222,s. Better than 153 156 158s and 170 though

As an example of the power difference an 802 has on electric compared to diesel, on electric an 802 departing Durham southbound will just be coming off Durham viaduct and approaching the terrace houses of redhills lane when the motors second field kicks in (you hear a distinctive change of motor pitch) at around 40mph. On diesel the train will have passed redhills lane, passed under the A167 and be almost through Neville’s Cross Cutting and on to Relley Mill Viaduct before the second motor field kicks in. That’s about 1/2 mile, quite a difference. Reaching that same point on electric the train is reaching 65-70mph yet barely attaining 40 on diesel
Put another way, on electric we have allegedly had an 802 doing 145 on electric! On diesel they struggle to hit 122.... downhill...... with a tail wind!

 

[100andthirty]

As an example of the power difference an 802 has on electric compared to diesel, on electric an 802 departing Durham southbound will just be coming off Durham viaduct and approaching the terrace houses of redhills lane when the motors second field kicks in (you hear a distinctive change of motor pitch) at around 40mph. On diesel the train will have passed redhills lane, passed under the A167 and be almost through Neville’s Cross Cutting and on to Relley Mill Viaduct before the second motor field kicks in. That’s about 1/2 mile, quite a difference. Reaching that same point on electric the train is reaching 65-70mph yet barely attaining 40 on diesel
Put another way, on electric we have allegedly had an 802 doing 145 on electric! On diesel they struggle to hit 122.... downhill...... with a tail wind!

Pedantic point...........there is no "second field" on a three phase motor. What you are hearing is, in all probability a change of frequency. The three phase motors are fed with a variable voltage and variable frequency power supply to regulate the speed. These changes are usually smooth - ie you would hear a gradually increasing change in pitch - but some frequencies are often omitted to avoid any interference to lineside equipment. This can lead to sounds like you would hear when you change gear in a car. Indeed those sounds are often described in shorthand as "gear changing".

The difference in performance between diesel and electric performance on class 800/1 and 800/2s was explained in some detail in this article from 2017: https://www.railengineer.co.uk/bi-mode-trains-unlocking-opportunity/. That said, gimme50anyday illustrates the practical effect of different power to weight ratios well.

 

[Mikey C]

As others have said, the Stadler class 755/3 have the highest power to weight ratio of any trains in the UK; a short train with 2.5MW power is almost unheard of. That said the power is put down though only four wheelsets, so acceleration can sometimes be limited by available adhesion compared with units that have 8 or more motored wheelsets. The LU S8 stock can draw over 3MW from the power rails, but is a much longer and heavier train, so its power to weight ratio is not as good as the Stadler trains, but it does apply that power to the running rails though 32 wheelsets, so will be less affected by poor adhesions conditions.

How does the 2009 stock compare in acceleration with the S8s? A lower top speed but (relatively) modern track and tunnels, a similar generation of traction and no problems with rain etc to cope with! They really rocket away from the platforms

 

[100andthirty]

How does the 2009 stock compare in acceleration with the S8s? A lower top speed but (relatively) modern track and tunnels, a similar generation of traction and no problems with rain etc to cope with! They really rocket away from the platforms

It's hard to say. Generally S8 has been "detuned" to the performance of C stock in tunnel and A stock north of Finchley Road. In the areas where the TBTC has been enabled the full performance has been enabled, but acceleration and braking rates can be varied from the control room and with the current timetable there is no need for high performance. In addition because of the amount of open running and therefore adhesion risk, brake rates aren't as high as on the Victoria line and brake rates and acceleration rates are linked though the CBTC.

The Victoria line has - borrowing the old Rolls Royce automobile publicity - sufficient performance. There is no adhesion risk, and even though there are only 6 motor cars in the 8-car formation, I recall an initial acceleration rate of 1.3m/s/s. The nominal brake rate is 1.15m/s/s - the highest on the Underground.

When I was on the first test train that had no interior fittings, I recall that the train set off unexpectedly (brake release was silent) and the acceleration was so rapid that I managed to have an intimate examination of the floor!

 

[CEN60]

Purely from an uneducated passenger's point of view - Scotrail's newish 385 EMUs feel as if the driver has pressed a hyperspace button (but prior to them I was used to a 318 or 320 - so go figure!!)

 

[gimmea50anyday]

The GEC motors used in the 318/320 EMUs perform and output a very similar rating to the EE507 used on the 455 so you had approx 1000hp across 4 motors on 2 bogies. The 385 uses more powerful and efficient AC motors with 3 motor bogies on the 3 car and 4 motor bogies on the 4 car. Not sure how many motors or what their HP ratings are but Performance will certainly be a lot more spritely as a result!

 

[Railperf]

The GEC motors used in the 318/320 EMUs perform and output a very similar rating to the EE507 used on the 455 so you had approx 1000hp across 4 motors on 2 bogies. The 385 uses more powerful and efficient AC motors with 3 motor bogies on the 3 car and 4 motor bogies on the 4 car. Not sure how many motors or what their HP ratings are but Performance will certainly be a lot more spritely as a result!

I have some Class 385 figures somewhere - they are fast but not in the top 5. Still far better than the Class 170s they replaced.
EDIT: 0 to 60mph in 44seconds , 0-90mph in 103 seconds - 0-100mph in 148 seconds.

It's hard to say. Generally S8 has been "detuned" to the performance of C stock in tunnel and A stock north of Finchley Road. In the areas where the TBTC has been enabled the full performance has been enabled, but acceleration and braking rates can be varied from the control room and with the current timetable there is no need for high performance. In addition because of the amount of open running and therefore adhesion risk, brake rates aren't as high as on the Victoria line and brake rates and acceleration rates are linked though the CBTC.

The Victoria line has - borrowing the old Rolls Royce automobile publicity - sufficient performance. There is no adhesion risk, and even though there are only 6 motor cars in the 8-car formation, I recall an initial acceleration rate of 1.3m/s/s. The nominal brake rate is 1.15m/s/s - the highest on the Underground.

When I was on the first test train that had no interior fittings, I recall that the train set off unexpectedly (brake release was silent) and the acceleration was so rapid that I managed to have an intimate examination of the floor!

Has the S8 performance been increased since the withdrawal of A stock and C stock? I understood that was due to happen.

Cannot record 2009 stock for obvious reasons, but 1996 Jubilee line stock is pretty quick.

1996 stock reaches 20mph in 8,5 seconds - but a 755 is a tad quicker reaching 20mph in 7.4 seconds. But the rate of acceleration for the tube train reduces - and as a result it takes 26 seconds to reach 40mph - compared to 16 seconds for the 755! Absolutely laughable!!

As an example of the power difference an 802 has on electric compared to diesel, on electric an 802 departing Durham southbound will just be coming off Durham viaduct and approaching the terrace houses of redhills lane when the motors second field kicks in (you hear a distinctive change of motor pitch) at around 40mph. On diesel the train will have passed redhills lane, passed under the A167 and be almost through Neville’s Cross Cutting and on to Relley Mill Viaduct before the second motor field kicks in. That’s about 1/2 mile, quite a difference. Reaching that same point on electric the train is reaching 65-70mph yet barely attaining 40 on diesel
Put another way, on electric we have allegedly had an 802 doing 145 on electric! On diesel they struggle to hit 122.... downhill...... with a tail wind!

Yes, the 802's on diesel are 0-60mph in 91s, 0-90mph in 192s, and 0-100mph in 257s - will do 125mph down Dauntsey bank.
802's on electric have recorded 0-60mph in 42s, 90mph in 90s and 0-100mph in 111s. 125mph in 192s. So seriously faster
Original 2+8 HST could so 0-60mph in 92s, 0-90mph in 182s and 0-100mph in 240s

 

[Llama]

In the name of science, as a certain electrical engineer former YouTuber used to say (he also used to say "where's my 'ammer" a lot) I opened up 2x 3-car 331 on the WCML earlier. Lightly loaded, fairly dry rail although there was some slip where the railhead was wet under an overbridge when starting away. Timings were taken from the TCMS.
0-60 - 29 seconds.
0-100 - 75 seconds.
If there was no slip when starting away you might well be able to take a second off those times, as the slip happened at very low speed.

331s are very consistent in their performance, for instance leaving Chorley in the up direction and opening up progressively you normally always get to 95 bang on where the permissible speed rises from 95 to 100mph.

In a 319 you might be anything between low 60s and high 70s by the same point.

Edit - just seen Railperf's notes on 331s above - you might want to rethink those.

Note that 'full wang' from 0mph is frowned upon on 331s, you won't normally see them driven like that.

The acceleration on 331s doesn't 'tail off' noticeably at higher speeds. If a driver isn't careful they'll be well over 100mph in seconds. I'd love to know exactly what speed they'd reach, I have little doubt that it'd be easily well over 120-130mph.

For an example of the power delivery on 331s at higher speeds, on a 319 doing 75mph at Agecroft heading towards Bolton on the moderate rising gradient where the speed increases from 75-95 (then 100) you can be in full traction power (notch 4) for 5 miles or so in the 319 and if you're lucky, on a dry rail with no headwind you'll get from 75mph to somewhere approaching 90mph before you need to shut off power for the PSRs before Bolton. Most 319s barely manage 85mph.

In a 331 you'll go from 75-95 (there's a short 95mph PSR up past Clifton before it increases to 100) in about 25-30 seconds and then almost immediately 100mph once the permissible speed rises from 95-100. Just 1% traction power on the CPBC is enough to keep you steady at 100mph all the way, and you still have to keep an eye on the speedo to stop it going over the ton.

 

[Aictos]

Class 700s are quicker accelerating when on the OHL vice the 3rd rail and this is obvious to the passenger.

 

[hexagon789]

In the name of science, as a certain electrical engineer former YouTuber used to say (he also used to say "where's my 'ammer" a lot) I opened up 2x 3-car 331 on the WCML earlier. Lightly loaded, fairly dry rail although there was some slip where the railhead was wet under an overbridge when starting away. Timings were taken from the TCMS.
0-60 - 29 seconds.
0-100 - 75 seconds.
If there was no slip when starting away you might well be able to take a second off those times, as the slip happened at very low speed.

331s are very consistent in their performance, for instance leaving Chorley in the up direction and opening up progressively you normally always get to 95 bang on where the permissible speed rises from 95 to 100mph.

In a 319 you might be anything between low 60s and high 70s by the same point.

Edit - just seen Railperf's notes on 331s above - you might want to rethink those.

Note that 'full wang' from 0mph is frowned upon on 331s, you won't normally see them driven like that.

The acceleration on 331s doesn't 'tail off' noticeably at higher speeds. If a driver isn't careful they'll be well over 100mph in seconds. I'd love to know exactly what speed they'd reach, I have little doubt that it'd be easily well over 120-130mph.

For an example of the power delivery on 331s at higher speeds, on a 319 doing 75mph at Agecroft heading towards Bolton on the moderate rising gradient where the speed increases from 75-95 (then 100) you can be in full traction power (notch 4) for 5 miles or so in the 319 and if you're lucky, on a dry rail with no headwind you'll get from 75mph to somewhere approaching 90mph before you need to shut off power for the PSRs before Bolton. Most 319s barely manage 85mph.

In a 331 you'll go from 75-95 (there's a short 95mph PSR up past Clifton before it increases to 100) in about 25-30 seconds and then almost immediately 100mph once the permissible speed rises from 95-100. Just 1% traction power on the CPBC is enough to keep you steady at 100mph all the way, and you still have to keep an eye on the speedo to stop it going over the ton.

Those 331s sound very impressive! 100mph on 1% power uphill - compared to Mk3 EMUs of the 1980s it must be like night and day.

 

[Llama]

The characteristics of DC motors as on 319s, 321s etc and AC asynchronous motors on 323s, 333s and 331s etc are like night & day. 331s really do have effortless power available at all speeds, it takes a bit of skill to drive them smoothly and properly. There have been a glut of TPWS incidents where drivers have been caught out, and some allegations against the brakes on 331s but I've driven them as much as anybody else has including test & training runs, I've never had any issue with the brakes. The alleged problems are more likely to be driver misjudgement of speed. The only thing I'd change is the aggressiveness of the holding brake which makes smooth stops on 331s simply not possible.

When you think that solo 142s were running similar routes and would struggle to get near 70mph on that same stretch up to Bolton not that many years ago, things have come on a bit recently.

 

[Railperf]

In the name of science, as a certain electrical engineer former YouTuber used to say (he also used to say "where's my 'ammer" a lot) I opened up 2x 3-car 331 on the WCML earlier. Lightly loaded, fairly dry rail although there was some slip where the railhead was wet under an overbridge when starting away. Timings were taken from the TCMS.
0-60 - 29 seconds.
0-100 - 75 seconds.
If there was no slip when starting away you might well be able to take a second off those times, as the slip happened at very low speed.

331s are very consistent in their performance, for instance leaving Chorley in the up direction and opening up progressively you normally always get to 95 bang on where the permissible speed rises from 95 to 100mph.

In a 319 you might be anything between low 60s and high 70s by the same point.

Edit - just seen Railperf's notes on 331s above - you might want to rethink those.

Note that 'full wang' from 0mph is frowned upon on 331s, you won't normally see them driven like that.

The acceleration on 331s doesn't 'tail off' noticeably at higher speeds. If a driver isn't careful they'll be well over 100mph in seconds. I'd love to know exactly what speed they'd reach, I have little doubt that it'd be easily well over 120-130mph.

For an example of the power delivery on 331s at higher speeds, on a 319 doing 75mph at Agecroft heading towards Bolton on the moderate rising gradient where the speed increases from 75-95 (then 100) you can be in full traction power (notch 4) for 5 miles or so in the 319 and if you're lucky, on a dry rail with no headwind you'll get from 75mph to somewhere approaching 90mph before you need to shut off power for the PSRs before Bolton. Most 319s barely manage 85mph.

In a 331 you'll go from 75-95 (there's a short 95mph PSR up past Clifton before it increases to 100) in about 25-30 seconds and then almost immediately 100mph once the permissible speed rises from 95-100. Just 1% traction power on the CPBC is enough to keep you steady at 100mph all the way, and you still have to keep an eye on the speedo to stop it going over the ton.

Ooh. Which station did you depart from and going in which direction?
Those figures put the 331 3-car in 2nd place. Mighty impressive. But yes they are brutal at the start. Possibly my driver eased off.. But I don't know why he would have done.
317 319 321s 322's all do 0 to 60mph in around 60s, 80mph in 120s and 100mph... Eventually - around 300s. I imagine the 3-car versions are more spightly.

 

[Halish Railway]

I just timed a 331/1 in mildly damp conditions using a speedometer app on my phone.

0-60 in 45 seconds.

Pretty impressive given the conditions and the fact that power was applied smoothly.

 

[Railperf]

From what station and going where?

 

[Halish Railway]

From what station and going where?

From Burley-in-Wharfedale to Ben Rhdding.

 

[Efini92]

The characteristics of DC motors as on 319s, 321s etc and AC asynchronous motors on 323s, 333s and 331s etc are like night & day. 331s really do have effortless power available at all speeds, it takes a bit of skill to drive them smoothly and properly. There have been a glut of TPWS incidents where drivers have been caught out, and some allegations against the brakes on 331s but I've driven them as much as anybody else has including test & training runs, I've never had any issue with the brakes. The alleged problems are more likely to be driver misjudgement of speed. The only thing I'd change is the aggressiveness of the holding brake which makes smooth stops on 331s simply not possible.

When you think that solo 142s were running similar routes and would struggle to get near 70mph on that same stretch up to Bolton not that many years ago, things have come on a bit recently.

Why didn’t you fail them all for the AWS being too loud?

 

[Llama]

Ooh. Which station did you depart from and going in which direction?
Those figures put the 331 3-car in 2nd place. Mighty impressive. But yes they are brutal at the start. Possibly my driver eased off.. But I don't know why he would have done.
317 319 321s 322's all do 0 to 60mph in around 60s, 80mph in 120s and 100mph... Eventually - around 300s. I imagine the 3-car versions are more spightly.

I'll furnish you with a PM with the details of location.

Yes the 331/0s with 66% adhesive weight are quite a bit quicker off the mark than the /1s, which have 30 tons of dead weight in the TS car and only 50% adhesive weight. The double 331/0 sets in the North West are a couple of seconds quicker to get up to say 100mph than a single /0 set is.

Why didn’t you fail them all for the AWS being too loud?

Pardon? I can't hear you

 

[Ceat0908]

390s, above 60mph, seem to reach 125 ridiculously quickly when compared to 80x. Although they get moving much quicker. I may be wrong, but I believe that’s because below 60mph they only use 60-80% of the power that is available?

 

[Railperf]

390s, above 60mph, seem to reach 125 ridiculously quickly when compared to 80x. Although they get moving much quicker. I may be wrong, but I believe that’s because below 60mph they only use 60-80% of the power that is available?

Yes definitely the 801's are quicker from rest to 60mph. 390's 60 to 125mph time is quicker though (not in eco mode)

 

[Ben Bow]

DMU wise, 185's do 0-60 on level track, with all three engines running, in around 68-69s.

 

[Railperf]

DMU wise, 185's do 0-60 on level track, with all three engines running, in around 68-69s.

Yes. That is right!

 

[Railweigh]

I would imagine that as technology improves, things have moved on a fair bit in wheelslip protection compared to a tatty 15x!

195’s are absolutely useless when it’s slippy. Worst units in our fleet by far.

 

[Aictos]

What about the Class 395s on the HS1 running lines between St Pancras and Ashford International?

The unit I was on yesterday I logged at doing 141mph and before anyone says that's not possible, I just stress I was using a speed app in my android device using GPS and yes I know it's not 100% accurate.

I did notice every so often the unit would creep to 140mph then would reduce speed to a average of 138mph.

I'm sure we hit 50mph before we fully left Stratford International platforms.

 

[hexagon789]

What about the Class 395s on the HS1 running lines between St Pancras and Ashford International?

38 seconds to 60mph

The unit I was on yesterday I logged at doing 141mph and before anyone says that's not possible

On the contrary, it's perfectly possible.

Now I'm not sure if the 395s themselves have an overspeed limiter, but the TVM430 will allow an overspeed margin of 15km/h at over 160km/h before intervening with a brake application.

Though as you rightly say such methods of speed recording are not 100% accurate, but it's very possible you did touch 141mph, don't feel you have to rule it out straight off the bat!