Question regarding turning Class 68 engines off

[coppercapped]

SNIP

The difference between the use of DMUs and locos is clear now. Also that the 168s that do the Birmingham run can only comprise 4 carriages and so are not suitable for the flagship service needed on this line.

Not quite right! The 168s may be coupled together to form longer trains than 4 coaches. The length of trains that Chiltern use is defined by operational rather than technical reasons.

I assume and hope that the choice of a "freight" train to pull the 6 coach Silver Trains was the only one available. I realise the commercial need to provide the fastest possible service to Birmingham was paramount. Unfortunately the residents at Marylebone have to suffer for this decision.

You have misunderstood. The company which supplies the Class 68s (DRS) is a company whose main business is operating freight trains but their business includes the chartering of locomotives to other users. Therefore the Class 68s were specified as 'mixed traffic' locomotives - they are not freight locomotives per se. They can haul freight trains but, being equipped with an Electrical Train Supply, they can supply electrical power to hauled (as distinct from self-propelled) passenger carriages and are capable of 100mph.

The franchise (and, presumably the contract with DRS) is due for renewal in 2021, does anyone know of an alternative to the 68s which would pull 6 coaches to Birmingham at a good speed without the noise side effect?

There are only two modern locomotives in the UK which have (a) sufficient power, (b) are equipped with ETS and (c) have a sufficiently high top speed. These are the Class 67 and Class 68. The Class 68 is newer, meets the Stage IIIA emission regulations and is more effective at putting its horsepower on the rails. This is why Chiltern changed from the Class 67 to the Class 68.

I don't like to underline what other people have already said but railways are an industrial concern and noise and emissions tend to go with them just as with some other branches of industry. The operators try to be good neighbours - but there are physical limits.

Is there an alternative to the 168s which could deliver the 6 carriage solution?

The Class 168s can easily be coupled together to form longer trains. That is not the issue which was when Chiltern wanted to buy more DMUs with a 100mph top speed the manufacturer had stopped making them. Chiltern then looked for an alternative and decided on rebuilding some old Mark 3 carriages and hauling them with the Class 67 locomotives. This background was explained in a speech by Adrian Shooter, the ex-Chairman of Chiltern Trains, to a meeting of the IET just before Christmas 2016. The video is available on Youtube.

There are 6 carriage DMUs operating on the other lines, might one hope that, when the new franchise comes and the need to replace the older DMUs, we might find a low emission, low noise alternatives to the 68s.

This is quite possible - and indeed highly likely but only after the costs of the significant rebuild of the Mark 3 stock has been amortised.

 

[ac6000cw]

If anyone is interested in air pollution related statistics (rather than just headlines), you might find this episode of the Radio 4 'More or Less:Behind the Stats' programme interesting - http://www.bbc.co.uk/programmes/p04hxmrg (the air pollution discussion starts around 18 minutes in).

 

[coppercapped]

Will Chiltern be forced to replace/refurbish their existing DMU fleet to comply with Stage 111b requirements or does it only apply to replacement by reason of age?

As najaB has stated, and as I wrote clearly in my earlier posting, the EU emissions regulations apply only to new designs and builds. Making rules retrospective would be legally, financially and morally wrong.

 

[M7R]

The class 68 meets Euro 3a (not 3b), the limit for which is 7.4g/kW-hr for engines of greater than 2000 kW (which the 68 is). See https://www.dieselnet.com/standards/eu/nonroad.php and scroll down to the 'Rail Traction Engines' section at the bottom of the page.

Part of my day job is passenger vehicle emissions, and in that world just because you have a limit does not mean you only just scrape under it, this gives no room for durability, plus what you tend to find is there is always a trade off, and I would not expect the NOx to be that close to the limit.

The only way you would know for sure is to actually see the approval, but that is not something Joe public normally sees, nor is it something that is straight forward to understand at times.

I have not looked at any heavy duty approvals in detail mind but even though the testing is different to the car world the principles are still the same.

 

[jopsuk]

As najaB has stated, and as I wrote clearly in my earlier posting, the EU emissions regulations apply only to new designs and builds. Making rules retrospective would be legally, financially and morally wrong.

The standards do only apply to new build, but rules can be put in place that ban or restrict vehicles (certainly road vehicles) that do not meet a particular level of the standard.

 

[KingDaveRa]

The class 68 was built as a mixed traffic locomotive and not for just freight. As for suitable alternative that is available now, there are class 67s. Failing that there are quite a few pieces of heritage traction out there as well. And if you think a 68 can have a dirty exhaust, you should see some of the heritage stuff.So short of full electrification I don't think there is a viable alternative to the 68s.

Why did Chiltern stop using the 67s?

 

[t_star2001uk]

Why did Chiltern stop using the 67s?

Cost was one of the main issues..

 

[ExRes]

Why did Chiltern stop using the 67s?

I only drove 67s for a short while, until the end of 2000, so I'm not aware if changes were made to the train supply system after that, suffice to say that they made such an awful noise that we were banned from using the supply at any station call, at the PRDC ground supply was used until shortly before departure

If they still make the same row now that they made when newly delivered then God knows what the 68s are doing if people are complaining about them and didn't? when 67s were being used, or were the same complaints being made then?

 

[najaB]

If they still make the same row now that they made when newly delivered then God knows what the 68s are doing if people are complaining about them and didn't? when 67s were being used, or were the same complaints being made then?

The 'quality' of the noise is quite different between the two. You can hear a 68 a long time before you can hear a 67 even though the decibel level is slightly lower.

 

[ExRes]

The 'quality' of the noise is quite different between the two. You can hear a 68 a long time before you can hear a 67 even though the decibel level is slightly lower.

There was certainly no quality about a 67 squealing like a stuck pig in mid power range when the train supply was in use, or when it wasn't come to that ......

 

[SpacePhoenix]

There was certainly no quality about a 67 squealing like a stuck pig in mid power range when the train supply was in use, or when it wasn't come to that ......

On a dvd about a TPO train I don't recall hearing the 67 squealling like a pig (wouldn't that be a 442's job anyway), do you know of a good youtube video that shows the noise?

 

[ExRes]

On a dvd about a TPO train I don't recall hearing the 67 squealling like a pig (wouldn't that be a 442's job anyway), do you know of a good youtube video that shows the noise?

I'm sorry, I'd like to help but I get a recurrence of my PTSD when exposed to visual or aural reminders of 67s

:eek:

 

[t_star2001uk]

Definitely not the quietest or best riding machines out there...

 

[putabidin]

Can you help me please?
Can't get my head round this.
Re DMUs.
Is every carriage within a set a DMU or are there seperate carriages as well?

eg does a four carriage 168 Clubman set comprise 2 DMUs and 2 carriages? And is that a set configaration or can it be altered to a 3 carriage set?

On the Marylebone/Aylesbury line which I used to travel when I lived outside of London, the trains (165s?) could be anything from 2 to 6 carriages long.
How is that managed and configured? Apart from the drivers end, where are the DMUs placed?

It ssounds an absolute nightmare to manage this.

 

[Aws87024]

Can you help me please?
Can't get my head round this.
Re DMUs.
Is every carriage within a set a DMU or are there seperate carriages as well?

eg does a four carriage 168 Clubman set comprise 2 DMUs and 2 carriages? And is that a set configaration or can it be altered to a 3 carriage set?

On the Marylebone/Aylesbury line which I used to travel when I lived outside of London, the trains (165s?) could be anything from 2 to 6 carriages long.
How is that managed and configured? Apart from the drivers end, where are the DMUs placed?

It ssounds an absolute nightmare to manage this.

A Diesel multiple unit (DMU) is made us of X number of cars (also known as carriages) which are kept in fixed formations (referred to as a unit). A class 168 DMU has 2, 3 or 4 cars depending on the individual unit, but in normal circumstances that unit always has the same number of cars. Units can be coupled to form longer trains. A class 165 has 2 or 3 cars per unit so 2 3 car units could be coupled to make a 6 car train.

 

[najaB]

Can you help me please?
Can't get my head round this.
Re DMUs.
Is every carriage within a set a DMU or are there seperate carriages as well?

A Diesel Multiple Unit (DMU) is a train consisting of one or more self-powered carriages. In some DMUs all carriages are powered, in others there are unpowered trailer carriages. This is different to loco-hauled formations such as the Class 68+Mark 3 sets where there is one locomotive and several unpowered carriages.

The lead and end vehicles in a DMU feature driving cabs which allows the train to be driven from either end. To achieve the same with loco-hauled sets requires the set to be either 'top-and-tail' (a locomotive at either end) or a driving cab is provided at the opposite end with controls which are connected to the locomotive (this is the function of the Driving Van Trailer (DVT) in Chiltern's case).

The Class 168s that Chiltern use have no trailer cars - they are all self-powered with a 422hp diesel engine under each carriage. They are in fixed formations of three or four carriages and sets can be joined together to provide additional capacity.

 

[TimboM]

Can you help me please?
Can't get my head round this.
Re DMUs.
Is every carriage within a set a DMU or are there seperate carriages as well?

eg does a four carriage 168 Clubman set comprise 2 DMUs and 2 carriages? And is that a set configaration or can it be altered to a 3 carriage set?

On the Marylebone/Aylesbury line which I used to travel when I lived outside of London, the trains (165s?) could be anything from 2 to 6 carriages long.
How is that managed and configured? Apart from the drivers end, where are the DMUs placed?

It ssounds an absolute nightmare to manage this.

The whole thing is called the "Diesel Multiple Unit". Depending on the type they can be anything from one (e.g. a Class 153) to (I think) five carriages long (e.g. the Voyagers) for a single set. Typically the suburban/local ones are 2 or 3 cars.

You can then couple single sets together to make long units (e.g. 2x 3 car = 6 car unit). These are simply two of the above joined.

Within these some of the 'carriages' will be powered/driving units with the motors in each 'carriage' - usually slung underneath. The end 'coaches' with the cabs are I believe almost always powered. The 'middle' coaches (without cabs) can then either be powered or non-powered depending on the type of DMU and the various factors involved to ensure enough power/weight ratios; e.g. a 5 car DMU may only have/need 4 cars powered and one un-powered.

Added to the above, for certain types of DMU, for example with the Class 168 you can get 3-car variants and 4-car variants, so some sets will have an extra coach added. DMUs typically stay in their "sets" though - i.e. once it's set up as a 4 car it will stay as such.

Hopefully this gives some background (and doesn't add to the confusion).

I'm pretty sure the 3-car Class 168s have a 422hp diesel engine in each 'carriage'. I THINK the 4-car does too (i.e. the 4th carriage comes with it's own motor as well) - I'm sure others will confirm. [EDIT: najaB has confirmed all are powered]

 

[najaB]

The whole thing is called the "Diesel Multiple Unit". Depending on the type they can be anything from one (e.g. a Class 153) to (I think) five carriages long (e.g. the Voyagers) for a single set.

A Class 800 in diesel mode isn't technically a DMU but they are nine carriages long.

 

[CyrusWuff]

A DMU is made up of a number of carriages. In Chiltern's case, the breakdown is as follows:

• Class 121 (aka "Bubble Car") - 1 coach
• Class 165/0 - 2 and 3 car
• Class 168 - 2, 3 or 4 car
• Class 172 - 2 car

Other than the Bubble Cars, which can only work singly or with each other, the rest of the DMU fleet can be coupled together as needed, subject to a maximum theoretical length of 12 carriages.

I say theoretical because most Chiltern stations can only accommodate 9 carriages in a platform. In practice, however, the maximum planned length (apart from two trains in the morning peak) is 8 carriages.

 

[Roast Veg]

--deleted

 

[TimboM]

A Class 800 in diesel mode isn't technically a DMU but they are nine carriages long.

Bit off topic, but what would you call it?

(And if we go even more off topic and talk about EMUs, then there's Class 373 Eurostars which are up to 20 cars long, but let's not go there...!)

 

[najaB]

Bit off topic, but what would you call it?

It's a bi-mode.

 

[TimboM]

It's a bi-mode.

A "DorEMU"

 

[putabidin]

A Diesel multiple unit (DMU) is made us of X number of cars (also known as carriages) which are kept in fixed formations (referred to as a unit). A class 168 DMU has 2, 3 or 4 cars depending on the individual unit, but in normal circumstances that unit always has the same number of cars. Units can be coupled to form longer trains. A class 165 has 2 or 3 cars per unit so 2 3 car units could be coupled to make a 6 car train.

Would each car have an engine and a driving cab, even if it was the middle one of a set of three? I presume not every car can be driven seperately, or can it?

How are they configured?

Sorry if these seem basic questions.

 

[najaB]

Would each car have an engine and a driving cab, even if it was the middle one of a set of three? I presume not every car can be driven seperately, or can it?

No. As I said only the end carriages have driving cabs, the intermediate ones do not. Even the end carriages can't necessarily be driven by themselves as some designs put equipment (e.g. air compressors) into the intermediate vehicles.

As an example, there are two Virgin Voyager driving carriages (the end carriages of one set) that cannot be used as their intermediate carriages were used to extend other sets from four to five carriages.

 

[rebmcr]

Class 800 are Electro-Diesel Multiple Units -- EDMUs.

The longest DMUs in regular service in the UK are (I think) the Class 222s which have a 7-carriage variant.

 

[t_star2001uk]

No. As I said only the end carriages have driving cabs, the intermediate ones do not. Even the end carriages can't necessarily be driven by themselves as some designs put equipment (e.g. air compressors) into the intermediate vehicles.

As an example, there are two Virgin Voyager driving carriages (the end carriages of one set) that cannot be used as their intermediate carriages were used to extend other sets from four to five carriages.

165s, 168s and 172 vehicles are essentially self contained vehcles. They can be moved under thier own power but not in passenger service. Each unit will consist of a pair of Driving Motor Coaches with, on some units one or two Motor Opens in the middle. Of course this is for Chiltern units, other TOC's may differ. The maximum number of coaches that can be operated in multiple is 12, but operationally the maximum we operate in passenger service is 8. There is, or there used to be, a 9 car ECS out of Marylebone late at night...

 

[najaB]

165s, 168s and 172 vehicles are essentially self contained vehcles. They can be moved under thier own power but not in passenger service.

Thanks. I thought that was the case with the Turbostar family but wasn't sure.

 

[putabidin]

No. As I said only the end carriages have driving cabs, the intermediate ones do not.

Sorry. Letters crossed.

I understand now except to ask, does each set have to have a driving cab at each end, or can it arrive at Marylebone with one at the front only, and another one get coupled to the other end for departure?

And, to bring us back to residents issues (and sorry if this has already been answered, but my head is reeling),is there any way that the existing Silver carriages, on which much money has been spent, could be incorporated into a DMU set up as an unpowered car?

 

[SpacePhoenix]

Can driving motor coaches of 175s, 180s and 185s operate on their own (obviously not in passenger service)?