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Author Topic: Class 802s  (Read 12752 times)
DaveHarries
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« on: April 21, 2018, 01:32:27 am »

Morning all,

For anyone wondering I understand, from another forum, that the first two diagrams to be operated by the Hitachi-built Class 802s have been penciled in to be as follows:

1A72 0553 Plymouth - London Paddington
1D20 0950 London Paddington - Oxford
1P26 1201 Oxford - London Paddington
1C89 1633 London Paddington - Exeter St. Davids
1A98 1955 Exeter St. Davids - London Paddington

1C04 0730 London Paddington - Penzance, via. Bristol Temple Meads
1A98 1400 Penzance - London Paddington
1C96 2003 London Paddington - Plymouth

Both diagrams understood to be planned for 2x 5-carriage trains and to start Monday 16th July.

I have been giving these trains some thought in regards summer operation on the Par to Newquay route and I wonder whether the through Newquay - London Paddington trains in summer will continue once the current Class 43 HSTs have gone. What I could see happening would be either:

1. The trains to call at Par where they would detach from each other with one set continuing to Newquay as a 5 carriage train. The set which runs the Newquay part then rejoins to the set it earlier detached from for the rest of the trip to London Paddington

2. Same as 1 but the second set continues to Truro and terminates there. For the return journey both trains join up again at Par for the trip back to London Paddington

3. No Class 802s up the Newquay line at all but additional local stoppers running instead between Par and Newquay

Saying that I was on a 10-car Class 800 from Bristol Parkway to Cardiff Central on Friday 20th April and the set quite easily managed a hill start on the incline immediately before Cardiff Central so I wonder if the gradient from Tywardreath Highway LC to Luxulyan would be a problem for a 5-car Class 802: it might not be.

HTIOI,
Dave
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bignosemac
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« Reply #1 on: April 21, 2018, 07:42:57 am »

Already mentioned here:

http://www.firstgreatwestern.info/coffeeshop/index.php?topic=18792.msg235407#msg235407

I'll leave the mods to mull over merging with the existing IET thread, or deciding to have a seperate Class 802 topic...
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grahame
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« Reply #2 on: April 21, 2018, 07:52:55 am »

Already mentioned here:

http://www.firstgreatwestern.info/coffeeshop/index.php?topic=18792.msg235407#msg235407

I'll leave the mods to mull over merging with the existing IET thread, or deciding to have a seperate Class 802 topic...

Ah - the nightmare of having such a busy forum that topics such as that those previous 802 diagrams got swamped with follow ups.    I am inclined for the moment to leave this thread here alone and let discussion develop - decide on merges, etc, later on for clarify as it heads from being a current conversation towards an archived resource. I'm minded that at than point a separate 802 thread may make the data easier to find.
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stuving
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« Reply #3 on: April 21, 2018, 10:41:16 am »

...
Saying that I was on a 10-car Class 800 from Bristol Parkway to Cardiff Central on Friday 20th April and the set quite easily managed a hill start on the incline immediately before Cardiff Central so I wonder if the gradient from Tywardreath Highway LC to Luxulyan would be a problem for a 5-car Class 802: it might not be.

If you ever find any 80x stuck on a hill, with its wheels not slipping (or trying to), you are entitled to be very rude about Hitachi.

The IEP requirement says they should be able to "start and climb any gradient encountered on the IEP Network" and (for avoidance of doubt) 1 in 37. And that applies to a nine-car with only one engine, though obviously that will never reach much of a speed.

The metaclass's figure of merit (fraction of weight on motored axles) is 0.59, versus 0.33 for an HST and 0.5 for all relevant DMUs. And it increases with passenger load, while for an HST in decreases.

The other thing needed is enough motor torque; that's a a matter of motor/drive design that Hitachi just have to get right. But the traction force needed to hold still on 1 in 37 would accelerate the train at 0.27 m/s2 on the level - and I'm sure they do that; it's well below the specified maximum of 0.75 m/s2 at zero speed.
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Andy
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« Reply #4 on: April 21, 2018, 11:30:54 am »

Morning all,



I have been giving these trains some thought in regards summer operation on the Par to Newquay route and I wonder whether the through Newquay - London Paddington trains in summer will continue once the current Class 43 HSTs have gone. What I could see happening would be either:

1. The trains to call at Par where they would detach from each other with one set continuing to Newquay as a 5 carriage train. The set which runs the Newquay part then rejoins to the set it earlier detached from for the rest of the trip to London Paddington

2. Same as 1 but the second set continues to Truro and terminates there. For the return journey both trains join up again at Par for the trip back to London Paddington

3. No Class 802s up the Newquay line at all but additional local stoppers running instead between Par and Newquay

Saying that I was on a 10-car Class 800 from Bristol Parkway to Cardiff Central on Friday 20th April and the set quite easily managed a hill start on the incline immediately before Cardiff Central so I wonder if the gradient from Tywardreath Highway LC to Luxulyan would be a problem for a 5-car Class 802: it might not be.

HTIOI,
Dave

I wonder if it might be worth trying out a split at Par, with a Newquay portion as you mention, and the second portion continuing to Falmouth rather than stopping at Truro. The set-up at Penryn (dynamic loop/platform length) might make this impracticable, though. 
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ChrisB
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« Reply #5 on: April 21, 2018, 05:35:59 pm »

Is there really enough traffic on the Falmouth branch for a 5car 802? hmmmm
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grahame
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« Reply #6 on: April 21, 2018, 06:07:15 pm »

Is there really enough traffic on the Falmouth branch for a 5car 802? hmmmm

Is there really enough traffic west of St Erth for a 5 car 802?

In all seriousness, I don't know the answer ChrisB.   However, I wonder whether there would be sufficient interest / extra traffic generated by through London trains from Cornish branches a couple of times each day - say late morning from each appropriate branch to London, and late morning / early afternoon from London to each appropriate branch.

Immediate issue one "what about stock efficiency / how would we get that in place".  Perhaps divert something that would head to Penzance to [Falmouth/other] with a connection into a branch unit at [Truro/other] for Penzance - is there some sort of model in the way the unit for the Newquay branch is provided post-peak?

Immediate issue two "would it be robust if the main line service was not running to time".

Potentially attractive if it were to bring more people to rail - on longer journeys too - off peak.

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DaveHarries
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« Reply #7 on: April 21, 2018, 06:19:21 pm »

I guess that perhaps one of the branches could perhaps be experimented with for a through service to / from Plymouth at peak times: could be tried once per day to start with. Falmouth to Plymouth anyone? Or am I standing at the wrong platform (as opposed to barking up the wrong tree)? One thought here is that a 10-car unit could split at Truro with 5 carriages to Falmouth and 5 to Penzance with the Falmouth set (for example) joining a 5-car set at Truro on its return trip.

Dave
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stuving
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« Reply #8 on: April 21, 2018, 06:20:49 pm »

The metaclass's figure of merit (fraction of weight on motored axles) is 0.59, versus 0.33 for an HST and 0.5 for all relevant DMUs. And it increases with passenger load, while for an HST in decreases.

I should, for completeness, have given the numerical implications of FMWA. Given some simplifying assumptions of the usual kind, it tells you what wheel/rail friction coefficient is required to climb a given gradient (other than by momentum alone).

Here are the numbers for 1 in 37:

trainFMWA*coeff
5-car 80x0.590.046
9-car 80x0.560.048
e.g. 1660.50.054
4+2 HST0.490.055
8+2 HST0.330.082
4+2 HST/one power car dead   0.2450.110
8+2 HST/one power car dead   0.165    0.164
(*Some values rely more on guesswork than others.)

There's quite a difference between the top and bottom of that ranking order. Getting high levels of steel/steel friction isn't impossible, even as high as 0.2, provided you keep the track and wheels clean and dry (indoors is best). But it can't be relied on, so towards the bottom of the table the probability of "poor rail conditions" that stop your train is unacceptably high. Hence the rules about half-dead HSTs and steep banks.
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« Reply #9 on: April 21, 2018, 07:55:30 pm »

I think the main problem with sending one down the Falmouth branch is platform length.
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« Reply #10 on: April 22, 2018, 08:17:17 pm »

I understand that a three car unit is the largest combo that can run on Falmouth in public service, providing it DOESN'T stop at Falmouth Town. FMT is only able to handle two cars.
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grahame
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« Reply #11 on: April 22, 2018, 09:11:18 pm »

I understand that a three car unit is the largest combo that can run on Falmouth in public service, providing it DOESN'T stop at Falmouth Town. FMT is only able to handle two cars.

Fixable with selective door opening and some signage?  More of a concern would be increased station dwells if it were to fit in (or fail to fit) with the half hourly clockface. Delays could cause chaos for hours ....
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« Reply #12 on: April 22, 2018, 09:50:19 pm »

Dwell time would inevitably increase due to pax shuffling along the locked carriages to those which are unlocked, even if carriages 2, 3 and 4 platformed at all Stations other than FMT. FMT would be horrendous with some pax inevitably moving through 2 carriages, if 2 and 3, or 3 and 4 were the chosen platformed vehicles. As much as I'd like to see 802's on Cornish Branches, other than NQY non stop the hurdles are far too great.
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eightf48544
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« Reply #13 on: April 23, 2018, 08:43:36 am »

rumour has it that the prototyp 802 is marroned on teh franco/Germn border.

The French are saying "Non" to it being hauled to Calais. no safety case.
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stuving
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« Reply #14 on: April 23, 2018, 09:26:00 am »

rumour has it that the prototyp 802 is marroned on teh franco/Germn border.

The French are saying "Non" to it being hauled to Calais. no safety case.

According to rail magazine last week:
Quote
Two more five-car 802/0s (802003/004) are on their way from Pistoia (Italy), where Hitachi Rail Europe is building the fleet. However, they are currently unable to travel through France due to strike action by SNCF.

That sounds very likely, as the sneaky strikes with three days at work at a time have severely impacted all SNCF freight workings.

Those are the second pair needed for the service launch, the first (from Kasado) already being here. And as 802s are minor variants on the 800s already in service, they hardly prototypes. They are first out of the newly-acquired Italian factory, which is in some respects more worrying - you can foresee a whole new set of teething problems.
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