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IEP v HST

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Sean Emmett

Posts: 131
IEP v HST - Posted: February 5, 2017 - 6:11 PM Quote and reply
Lots of discussion in media and online re likely performance of IEP on diesel compared with HST.

I appreciate it's not all about power to weight ratio, but I have come up with the following table as a yardstick.

Can anyone confirm weights of the 5/9 car IEPs, both bimode and 'electric-only' versions. The latter will of course still have one diesel engine for shunting and providing hotel power in emergencies.

Also what rating do the Class 395 Javelin's have on 750V DC?


IEP v HST Comparison Table

43 2+7 HST XC 4,500 HP,372t, 12.1 HP/ton
43 2+8 HST GW 4,500 HP,404t, 11.1 HP/ton
43 2+9 HST EC 4,500 HP,437t, 10.3 HP/ton

91+8+DVT 6,090 HP, 442t,13.8 HP/ton
91+9+DVT 6,090 HP, 484t,12.6 HP/ton

180 Adelante 3,750 HP, 249t, 15.1 HP/ton

220 Voyager 3,000 HP, 192t, 15.6 HP/ton
221 Super Voyager 3,750 HP 274t, 13.7 HP/ton

390/0 9 Car Pendo 6,840 HP 458t, 15.2 HP/ton
390/1 11 Car Pendo 7,980 HP 546t, 14.6 HP/ton

395 Javelin AC 4,480 HP, 272t, 16.5 HP/ton
395 Javelin DC 2,252 HP?, 272t, 8.3 HP/ton

800/1 IEP 5car - electric ??
800/1 IEP 5car- diesel 2,250 HP, 245t 9.2 HP/ton
800/3 IEP 9car Bi Mode - electric ??
800/3 IEP 9car- diesel 3,750 HP, 442t 8.5 HP/ton

801 IEP 5 Car - electric only ?
801 IEP 9 Car - electric only ?

802 AT300 5 Car Bi Mode - electric ?
802 AT300 5car- diesel 2,820 HP, 245t, 11.5 HP/ton

802 AT300 9 Car Bi Mode - electric ?
802 AT300 9 Car- diesel 4,700 HP, 442t, 10.6 HP/ton


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Lloyd-Roberts

Posts: 7
395s - Posted: February 6, 2017 - 8:45 AM Quote and reply

I cannot help you with the GWR. With regard to the 395s on 3rd rail - whereas I do not know the technicalities, I can tell you that they are markedly inferior to the 375s. A good 375 will comfortably attain 100 mph between Ashford and Westenhanger, up a grade of about 1:280m whereas the 395s have never exceeded 90 mph in my experience, despite being nonstop to Folkestone West.

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Sean Emmett

Posts: 131
Re: IEP v HST - Posted: February 7, 2017 - 3:41 PM Quote and reply
From Wikipedia https://en.wikipedia.org/wiki/Intercity_Express_Programme

DfT Spec: “The maximum weight of a full-length train was 362 tonnes (electric), 385 tonnes (bi-mode) and 392 tonnes (self-powered), with expected weights of around 332, 350 and 368 tonnes respectively or better.[15] The minimum top speed was 125 mph (201 km/h), with a minimum acceleration for all subtypes in both full- and half-length formations of over 0.575 m/s2 (1.29 mph/s) from starting to over 50 km/h (31 mph).”

Agility original bid “The full- and half-length trains were to be approximately 260 m and 130 m long respectively – the 26 m carriages were to be of aluminium construction, with the power cars of steel.[33] The quoted tare masses for full-length trains (412.5 t for the electric version) exceeded the tender's essential requirements (TS196[15]) by up to 50 tonnes (electric version)”.

I appreciate the design has evolved to under floor engines rather than engines in the driving end cars, but its all gone a little hazy regarding weights!

If 249 tonnes is right for a 5-car bi mode then that suggests basic weight of a coach is 45 tonnes plus 8 tonnes for each power pack. (2 x 45) + (3 x 53) = 249 tonnes, or 245 imperial tons
For a 9 car this suggests (4 x 45) + (5 x 53) = 445 tonnes, or 438 imperial tons.

Now I recon a GW 2+8 HST weighs 404 tons. With 2 X 2,250 hp MTUs that’s 11.1 hp/ton.

An EC 2+9 HST is say 437 tons, so that’s 10.3 hp/ton.

A 5 car class 800 bi mode on diesel will have 2,250 hp for 245 tons, that’s only 9.2 hp/ton!

A 9 car on diesel will have 3,750 hp for 438 tons, so 8.6 hp/ton.

But on the class AT300 the engines will work at their full rating of 940 hp.

So 5 car AT300 on diesel will have 2,820 hp for the 245 tons, 11.5 hp/ton so just beats the HST!

The 9 car AT300 on diesel will have 4,700 hp for 438 tons, 10.7 hp/ton – less than an HST.

I’m more than happy to be corrected!



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daveb0789

Posts: 15
Location: England
Re: 395s - Posted: February 9, 2017 - 12:07 AM Quote and reply
Lloyd-Roberts said:

I cannot help you with the GWR. With regard to the 395s on 3rd rail - whereas I do not know the technicalities, I can tell you that they are markedly inferior to the 375s. A good 375 will comfortably attain 100 mph between Ashford and Westenhanger, up a grade of about 1:280m whereas the 395s have never exceeded 90 mph in my experience, despite being nonstop to Folkestone West.


If I could add into the conversation I have driven both types. Only a 3/4 car 375 is capable of attaining the full 100 mph up the grade to Westenhanger by around Herringe. In multiple they have current restrictions - I believe the maximum permissible is 4000 amps. However this is still sufficient for an 8 car unit to attain 95 mph up the grade.
The 375/3s are a little bit less able than their 4 car sisters and will struggle to reach 100 up hill on this section.
Javelins are hampered by massive current restricting being imposed to avoid tripping the substations. Using the horsepower formula and the traction torque figures from the train management system, I've calculated just 2000 hp is available until around 50 mph when it starts to fall off and only around 1200 hp is available at 90 mph. This explains the Javelins poor high speed performance on third rail but they can still achieve 100 mph on the up line from Westenhanger to Ashford. 12 car Javelins are permitted 4000 amps rather than 3000 for a single unit so the performance differential while obvious isn't catastrophic. Javelins are also able to produce their full 232 KN up to 15 mph on D.C. power. This compares well to the 132 KN of a 4 car 375 which means a Javelin is in fact quicker off the mark and will stay with a 375 until 45 to 50 mph.

A point on those power to weight ratios. Electric traction produces its rated power at the wheel. Diesel traction will most likely produce a maximum of 80 percent of actual engine output at the rail.

The figures calculate show a Pendolinos power to weight ratio to be almost equal to that of the Javelin. Yet my experiences in a Pendolino don't match the figures. There is nowhere near the massive push in the back you get from a Javelin going to full power. Here's the reason why - electric traction is usually able to exceed its continuous rating during acceleration. Class 90s are a good example of this. 5000 hp continuous and 7860 maximum. But class 91s don't have a massively higher figure. 6300 maximum vs 6100 continuous. I believe that it's the same with the Pendolinos - their maximum power is not much more than their continuous rating.

Javelins are not like that. From a stand still on AC, 232 KN is produced from those 16 motors. Unlike on most traction where this figure rapidly falls off after 30 mph, the Javelin's doesn't until 50 mph and I've calculated based on motor torque figure it produces in excess of 6000 hp from around 50 to 80 mph. This is what makes it the fastest accelerating multiple unit in the U.K. bar none !

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Sean Emmett

Posts: 131
Re: 395s - Posted: February 15, 2017 - 9:19 PM Quote and reply
David and esp Dave thanks for this feedback.

I have raised the IEP v HST question on the Rail UK Forum and am getting vague answers. There's a suggestion that IEP on diesel limited to 110 mph can match HST schedules?

As the IEPs come from the same stable as the Javelins can we expect similar performance from the IEPs when on electric on GWML?

Sean



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daveb0789

Posts: 15
Location: England
Re: 395s - Posted: February 15, 2017 - 10:29 PM Quote and reply
Sean Emmett said:
David and esp Dave thanks for this feedback.

I have raised the IEP v HST question on the Rail UK Forum and am getting vague answers. There's a suggestion that IEP on diesel limited to 110 mph can match HST schedules?

As the IEPs come from the same stable as the Javelins can we expect similar performance from the IEPs when on electric on GWML?

Sean



The online data suggests each traction motor of an IEP will be rated at 226 kW (303 hp) which is more than one in a Javelin 210 kW (281 hp). But with 3 out of 5 cars motored this gives 14.8 hp/ton for the 5 car and 5 out of 9 vehicles powered : 13.7 hp / ton. This is using the weights in the thread as a guide.





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