Loco-hauled for Crosscountry?

[Jonny]

750 v. 780hp per coach isn't a big difference (and at that point, efficiency of the transmission is going to become significant, as well as draw of auxiliaries), and the 185 has a clear traction advantage through having way more powered axles.

Ah, but the 68 has the higher axle load, meaning higher total traction, as well as more efficient regenerative braking.

 

[captainbigun]

Ah, but the 68 has the higher axle load, meaning higher total traction, as well as more efficient regenerative braking.

It has what?! It turns amps back into diesel?!

68 plus stock was a point in time decision based upon lead time. It’s way past the original intended introduction. Given that TPE have other new fleets from Hitachi and CAF time will tell whether this was worth the punt. One thing for sure, it’s expensive and that’s going to arrive in the fares at some point.

 

[Intercity Exec]

750 v. 780hp per coach isn't a big difference (and at that point, efficiency of the transmission is going to become significant, as well as draw of auxiliaries), and the 185 has a clear traction advantage through having way more powered axles.

Class 185s have heavily detuned engines and aren't running at 750hp at all, they were rated at under 600hp last I heard. The advantages of this are fuel saving, less heat to dissipate and reduced engine wear. This is the reason the QSK19 engines on Class 185s are prone to hunting while others in use on the network are not (although they are still detuned but to a lesser extent).

 

[Bletchleyite]

Class 185s have heavily detuned engines and aren't running at 750hp at all, they were rated at under 600hp last I heard. The advantages of this are fuel saving, less heat to dissipate and reduced engine wear. This is the reason the QSK19 engines on Class 185s are prone to hunting while others in use on the network are not (although they are still detuned but to a lesser extent).

They also only use 2 out of the 3 on most of the network at any given time.

 

[Journeyman]

Voyagers are good in first class, 2nd class is not that comfortable I don't think, though still way better than Driving on the Motorway.

I agree, there's been several occasions when my decision to use CrossCountry on a long journey has been swung by the availability of a cheap first class ticket.

 

[Fearless]

BTW that would seem insanely good looking back to the old days of loco hauled where you'd often find a Class 47 on load 13!
Occasionally a 31 would stand in!

Ah, happy memories of seeing a feisty little 'Crompton' 33 bowling through Yatton at 60 mph, hauling a dead class 50 and 13 coaches!

 

[43096]

Ah, happy memories of seeing a feisty little 'Crompton' 33 bowling through Yatton at 60 mph, hauling a dead class 50 and 13 coaches!

Someone with username “Fearless” and a picture of a 50 as their avatar having happy memories of dead 50s being hauled by 33s? What the? Any self respecting Vac fan couldn’t stand the bean cans!

 

[Fearless]

Someone with username “Fearless” and a picture of a 50 as their avatar having happy memories of dead 50s being hauled by 33s? What the? Any self respecting Vac fan couldn’t stand the bean cans!

Ha ha! Point taken, but I had to admire the little thing anyway. Re my avatar, Fearless (in the photo) broke down approaching Gloucester about half an hour after that pic was taken! Par for the course at the time, but their appalling reliability didn't stop them being my faves. Along with the Deltics, of course.

 

[delticdave]

It has what?! It turns amps back into diesel?!

68 plus stock was a point in time decision based upon lead time. It’s way past the original intended introduction. Given that TPE have other new fleets from Hitachi and CAF time will tell whether this was worth the punt. One thing for sure, it’s expensive and that’s going to arrive in the fares at some point.

It transforms amps into heat! (Assuming that 68's are fitted with dynamic braking
.......)

 

[43096]

It transforms amps into heat! (Assuming that 68's are fitted with dynamic braking
.......)

Which is not regenerative braking. Regenerative braking puts electricity back into the overhead line or third rail, which can then be used by other trains.

 

[Darandio]

Which is not regenerative braking. Regenerative braking puts electricity back into the overhead line or third rail, which can then be used by other trains.

Regenerative braking isn't exclusively just for putting power back into the system. Given the Class 68 brochure specifically mentions regenerative braking, I assume that it can be fed back to the traction motors.

 

[Erniescooper]

Regenerative braking isn't exclusively just for putting power back into the system. Given the Class 68 brochure specifically mentions regenerative braking, I assume that it can be fed back to the traction motors.

I think you maybe thinking of the 88 but the 68 has a rheostatic dynamic brake with two resistor bank towers with blowers

 

[43096]

Regenerative braking isn't exclusively just for putting power back into the system. Given the Class 68 brochure specifically mentions regenerative braking, I assume that it can be fed back to the traction motors.

Errrrrrrrr. Dynamic braking is under braking, obviously, so why would you feed it to the traction motors? They generate the dynamic brake energy in the first place!

 

[Bletchleyite]

Errrrrrrrr. Dynamic braking is under braking, obviously, so why would you feed it to the traction motors? They generate the dynamic brake energy in the first place!

You could store it in a battery or other means of storage.

 

[Darandio]

You could store it in a battery or other means of storage.

Indeed, my response was more towards the blanket statement that regenerative braking is solely for putting current back to the system, which it isn't.

However, given that 43096 cannot respond to any post without having some high and mighty 'i know best' attitude, i'll leave him to it.

I think you maybe thinking of the 88 but the 68 has a rheostatic dynamic brake with two resistor bank towers with blowers

I wasn't, I was looking at the Class 68 brochure at the time.

 

[JohnMcL7]

Indeed, my response was more towards the blanket statement that regenerative braking is solely for putting current back to the system, which it isn't.

Given 43096 obviously knows best in every thread i'll leave him to it though.

I wasn't, I was looking at the Class 68 brochure at the time.

You've said it could feed power back to the traction motors but to do that there would need to be some form of energy storage to allow it to do that but I can't find any evidence the class 68 has such a system. The only reference I've found to the 68 and regenerative braking is someone speculating it could use a battery, (before the units were shipped) all others refer to it as dynamic braking or if it's regenerative breaking it's the class 88 they're referring to.

 

[43096]

However, given that 43096 cannot respond to any post without having some high and mighty 'i know best' attitude, i'll leave him to it.

Fine. I’ll leave you talking total nonsense then.

 

[delticdave]

Which is not regenerative braking. Regenerative braking puts electricity back into the overhead line or third rail, which can then be used by other trains.

Yes but, the 68 is a diesel, with no access to a third rail or OHEL. Energy storage & recovery is possible on a diesel loco, (as used in hybrid cars & buses) but it's not common yet.
Many diesels, albeit not in this country, have electric braking, dumping the energy from the motors into braking resistors.
Very common in N. America to control downhill speeds, rather than relying on their single-pipe air-brakes.

 

[HSTEd]

British diesels aren't equipped with resistance brakes?

That would seem to be odd as it is an obvious way to substantially reduce operating costs by reducing brake wear.

 

[43096]

Yes but, the 68 is a diesel, with no access to a third rail or OHEL. Energy storage & recovery is possible on a diesel loco, (as used in hybrid cars & buses) but it's not common yet.
Many diesels, albeit not in this country, have electric braking, dumping the energy from the motors into braking resistors.
Very common in N. America to control downhill speeds, rather than relying on their single-pipe air-brakes.

Agree with that. A diesel can make limited use of regenerative braking to power auxiliaries and train supply. Otherwise it uses rheostatic braking where the electrical energy is dissipated as heat. Both are covered by the term “electric braking” (or “dynamic braking”). Electric traction is far better at this as the energy generated by regenerative braking can be used by other trains, which can be a substantial energy saving (not to mention being more environmentally friendly).

 

[grumpyoldman01]

In the early 1990s, I was talking to a traction engineer employed by ABB who was familiar with the system installed on the Danish ME class diesels.

There was a suggestion that these would form the basis for class 48 locos for BR, and during the conversation he mentioned regenerative braking; I'm not a traction engineer, and so I responded with something like "hang on, we are taking about diesels, aren't we?" He replied "yes", and went on to explain that the energy generated when braking was used as an electric train supply for HVAC, etc; my interpretation of what he said was that ALL regenerated energy was fed into the train supply.

Running along the Dawlish sea wall was also discussed; his response can be summarized as "no problem!"

 

[Darandio]

Fine. I’ll leave you talking total nonsense then.

Nonsense? Please elaborate.

 

[delticdave]

British diesels aren't equipped with resistance brakes?

That would seem to be odd as it is an obvious way to substantially reduce operating costs by reducing brake wear.

Generally no, but the 68's do have them (see up-thread) as did the class 50's when new.
Wikipedia has quite a good explanation of why the 50's were de-cluttered....

Dynamic / regenerative braking is useful in (D)EMU's, especially when equipped with multiple traction motors, but UK loco-hauled train lengths / weights didn't justify the costs.
It's difficult to fit the equipment into our tight loading gauge locos & short trains. often using disc brakes don't need frequent brake shoe / pad replacement.
We don't have the long mountain grades that are common elsewhere, &,when BR converted from vacuum to air braking they were smart enough to fit the two-pipe system to passenger & freight cars.
The big advantage is, of course, that the driver can never "loose the air" when braking / releasing the train brake, the 2nd
(reservoir) pipe is keeping all the individual car reservoir tanks full, rather than recharging them via the train pipe, which can be a problem........

 

[modernrail]

With TfW seemingly making progress with a Class 67 and MK IV combination and apparently plenty of both going spare is this looking anymore like a good fix for Cross Country capacity issues? The leasing companies must be ready to do a very good deal to get the units back into use.

I did see a mention of gauging issues elsewhere on the thread but I find it a bit odd that it might be an issue on Cross Country routes but not on the previously virgin MK IV territory of TfW lines. Are they bigger than a HST carriage?

I would be very happy indeed with a MKIV on Cross Country routes. As they would be running under 125mph for much if their running they would also not be getting the same thrashing as they receive on the ECML.

When are the Cross Country Voyagers off lease to the extent this might be helpful to force a serious negotation?