377/6

[Peter Mugridge]

The fastest 3rd rail unit was a 442 that went 108mph, so especially for new gen emu's it shouldn't be that difficult.

Officially, yes, but unofficially the REP / TC sets could easily beat that. I've got a photo somewhere of a REP speedo jammed against the stop and it certainly carried on accelerating from there for a bit.

On another occasion I was on one that did Southampton Central to Waterloo non stop in under an hour - including waiting five minutes or so outside Waterloo for a platform.

Of course, in those days there were far fewer trains on the line each hour so the power supply was a bit more robust and the paths were more flexible...

 

[Class377/5]

Yeah, that's what I've always meant. If the 140 additional carriages were guaranteed we may be calling it the '256' order. The latest batches are of course rather different in their ways.

Very true.

Fair enough I suppose. Although I've also wondered why /7 is not numbered 727-734 as the build is otherwise identical? I should stop dabbling in TOPs!

Because it wastes space. If they ordered more five cars (perhaps to replace the 455's) they you might fill up the sub class. That said look at the 319's.

TSGN, just checking, is that the 'NX' livery as demonstrated on the latest 700 stock impressions? Is that also what FCC are repainting their 365s into over the C6X refurbishment?

This is what I've call the TSGN livery


Siemens Desiro City @ Farringdon by Sparkyscrum, on Flickr


365 in TSGN livery. by Sparkyscrum, on Flickr

Yes, because any DC power system could not supply the demand of several trains regularly running in service at 110mph. Much energy is wasted through friction as heat - 25% wastage I recall?

That's not quite correct. The current system is at the limit of what it can achieve but its more the shoe gear hitting the ramps as the conductor rail goes up and down. Over 100moh there starts to be more risk involved.

Your right tho the DC system does lose a lot of power.

 

[edwin_m]

That's not quite correct. The current system is at the limit of what it can achieve but its more the shoe gear hitting the ramps as the conductor rail goes up and down. Over 100moh there starts to be more risk involved.

Your right tho the DC system does lose a lot of power.

The reason for the loss of power is the much lower voltage. A lower voltage means a greater current and power loss is proportional to the current multiplied by itself. Hence even with substations much closer together (extra cost) the 750V system loses much more power than the 25kV. Also regenerative braking is less efficient on the 750V system because more of the energy is wasted transferring it to a train that needs it to accelerate somewhere else.

 

[jopsuk]

You could build 110mph suitable ramps, but you'd run into problems with gapping (even whilst moving) when running at reduced speeds. As I understand it the ramp angle is set for the speeds expected. Slow speeds require steep angles to minimise gapping, high speeds shallow angles to avoid smashing the shoes off.

 

[transmanche]

Also regenerative braking is less efficient on the 750V system because more of the energy is wasted transferring it to a train that needs it to accelerate somewhere else.

Also, I'm led to believe, that there has be another train quite nearby to 'benefit' from the regenerative braking on 750V DC. Whereas on 25kV AC it doesn't have to be as close by, due to the greater distance between substations (and of course benefits from lower current loss).

Although not being an electrical engineer, I may have totally misunderstood it!

 

[swt_passenger]

Also, I'm led to believe, that there has be another train quite nearby to 'benefit' from the regenerative braking on 750V DC. Whereas on 25kV AC it doesn't have to be as close by, due to the greater distance between substations (and of course benefits from lower current loss).

That's roughly it, because there's a key difference between the two systems. Having loads of trains around solves the problem that on the DC network the regenerated power cannot be fed back through the present generation of rectifiers into the distribution network. On the AC system I understand that the power was able to pass through the substation transformers in both directions with fairly straightforward mods to overcurrent protection devices.

There were expectations that DC re-gen would be difficult at the periphery of the network, I believe that's why much of the SWT testing took place near Weymouth.

 

[Class377/5]

Getting back on topic there's reports 377604 will arrive this week. However conflicting reports on different Yahoo groups on whether its left Derby yet or is leaving tonight.

 

[edwin_m]

That's roughly it, because there's a key difference between the two systems. Having loads of trains around solves the problem that on the DC network the regenerated power cannot be fed back through the present generation of rectifiers into the distribution network. On the AC system I understand that the power was able to pass through the substation transformers in both directions with fairly straightforward mods to overcurrent protection devices.

There were expectations that DC re-gen would be difficult at the periphery of the network, I believe that's why much of the SWT testing took place near Weymouth.

To allow regen back into the network from the DC system, the rectifiers would have to be replaced by inverters similar to those fitted to modern three phase traction drives, but higher rated as they could be handling several trains worth of current at once. This isn't particularly difficult to do, but would be costly due to the large number of substations especially if the future of some parts of the DC system is limited.

Without these inverters, to feed regenerated power into a train some distance away involves the regenerating train raising the voltage in the third rail. The power losses in the system mean that a large increase in voltage is needed to feed the power a relatively short distance, but the maximum voltage is limited by safety rules.

 

[starrymarkb]

Officially, yes, but unofficially the REP / TC sets could easily beat that. I've got a photo somewhere of a REP speedo jammed against the stop and it certainly carried on accelerating from there for a bit.

On another occasion I was on one that did Southampton Central to Waterloo non stop in under an hour - including waiting five minutes or so outside Waterloo for a platform.

Of course, in those days there were far fewer trains on the line each hour so the power supply was a bit more robust and the paths were more flexible...

I believe a solo REP was clocked at 115mph+ using a Radar gun during a night time speed run in Kent (as part of the Eurostar development)

 

[transmanche]

I believe a solo REP was clocked at 115mph+ using a Radar gun during a night time speed run in Kent (as part of the Eurostar development)

With something like 3,200hp at their disposal (needed for dragging 4-TCs around), I guess a solo one really could fly!

 

[Minstral25]

Getting back on topic there's reports 377604 will arrive this week. However conflicting reports on different Yahoo groups on whether its left Derby yet or is leaving tonight.

How many have been delivered so far?

 

[Jedipickles]

How many have been delivered so far?

None - Only 377064 has left as far as I'm aware which is 377604 which is still at Bescot

 

[Class377/5]

377601 came down for testing but went back to Derby awhile ago. 377604 will be the first unit for Southern. As I write this its just passed through Rugby.

 

[Manchester77]

Do these units have an interior fitted or will they go back at a later date after they've finished testing?

 

[Class377/5]

Do these units have an interior fitted or will they go back at a later date after they've finished testing?

No, only 377601.

377604 was delivered today. I saw it go by at Kennington Olympia

Video here of 377604

 

[JB25]

The 377/6s look a bit flatter on the front, not sure if I am imagining that or not?!

I take it these will be turning up fully fitted with GSM-R radios too?

 

[Class377/5]

The 377/6s look a bit flatter on the front, not sure if I am imagining that or not?!

I take it these will be turning up fully fitted with GSM-R radios too?

They are the same as the rest of the Electrostar fleet. See here for a video of 604 getting dragged.

Not sure about the GSM-R question tho.

 

[JB25]

No Southern 377s ate fitted with GSM-R yet they are all supposed to be done by the end of July. hock: I would be ASTOUNDED if these turned up with CSR fitted!

 

[Class377/5]

377605 is currently being dragged down from Derby to Stewarts Lane.

The final bit of the delivery is


7Z01 08:31 Wembley Yard to Stewarts Lane

Wembley Yard 08:31
Kensington Olympia 08:50
Stewarts Lane 09:01
Battersea Park 09:04 09:34
Stewarts Lane 09:37
Stewarts Lane Depot 09:48

 

[33056]

Make that 7Z71 09:49 Wembley Yard to Stewarts Lane (arr 10:53), currently running around 15 minutes late with 67016 / 67026 on the front.

 

[Class377/5]

Make that 7Z71 09:49 Wembley Yard to Stewarts Lane (arr 10:53), currently running around 15 minutes late with 67016 / 67026 on the front.

Curious the headlines coming down were 7Z70 Litchurch Lane - Bescot and 7Z71 Bescot to Wembley Yard. Was early for most of its journey expect around Rugby.

 

[33056]

Curious the headlines coming down were 7Z70 Litchurch Lane - Bescot and 7Z71 Bescot to Wembley Yard. Was early for most of its journey expect around Rugby.

There were two schedules for 7Z71, one for Bescot to Wembley Yard and the other through to Stewarts Lane leaving Wembley at 08:31, the latter one was cancelled. Guess they wanted a later path on the last bit for some reason.

 

[Class377/5]

377604 made it to Victoria last night with 377311.

Its been out most of the day too

0103 Victoria - Tonbridge
0200 Tonbridge - Victoria
0353 Victoria - Ashford
0544 Ashford - Sevenoaks
0640 Sevenoaks - Dover Priory
0821 Dover Priory - Grove Park depot
1016 Grove Park depot - Ashford
1150 Ashford - Stewarts Lane

The following rubs are booked for today.

1952 Stewarts Lane - Dover Priory
2311 Dover Priory - Victoria
0103 Victoria - Tonbridge
0200 Tonbridge - Victoria

 

[jon0844]

Have any buttons fallen off yet?

 

[Class377/5]

Have any buttons fallen off yet?

I don't know but I can now state that 377604 can couple to 377311. I've got the pictures to prove it!

 

[Southernrover]

Here is 377604 along with 377311 this morning on test passing Sevenoaks.

The middle part of the days activity was cancelled.

http://www.youtube.com/watch?v=JLl0DuY1UrA

 

[D365]

Here is 377604 along with 377311 this morning on test passing Sevenoaks.

The middle part of the days activity was cancelled.

http://www.youtube.com/watch?v=JLl0DuY1UrA

5+3 is a rather unusual 8-car formation; will we be seeing this in service? At least Class377/5 has had it proven

 

[CC 72100]

Didn't realise the 377/6s were 5 cars... so that means that every single combination of total vehicles up to platform length limits is now possible with 377s, as 5 was previously the impossible one

 

[Class377/5]

5+3 is a rather unusual 8-car formation; will we be seeing this in service? At least Class377/5 has had it proven

No. Simply put it was a test to see that the 377/6 coupled ok with another unit initially and having a unit coupled that passed to work on the mainline in case 604 fails and needs to be dragged away.

Once 604 is commissioned then it can act as the back up unit with future unit commissioning. The plan is for them to work mainly in pairs on the Southern Metro in peak, not so sure off peak. There is plans for them to escape London at weekends too.

 

[D365]

Didn't realise the 377/6s were 5 cars... so that means that every single combination of total vehicles up to platform length limits is now possible with 377s, as 5 was previously the impossible one

(less than 3 carriages, not an internet heart) is still not possible, nor will it ever be with the Electrostar and many other AC EMUs. The pickup vehicle, at least with this design, is never driving or motored.

I'm over-analysing, at least they're coupling, so far