Loco haulage of EMUs?

[Trainbike46]

You could always take a small loco and insert it into the middle of an emu rake. It wouldn't have to have cabs for a driver, it could be walk-through, you could fit it with 4x Daimler Benz V8 engines or some mix of battery packs. You could call the result a class 755.

exactly

I love how many of the posts here are just describing bimode FLIRTs, or in some cases something like it made of existing EMUs

 

[Nick Ashwell]

Can’t we just call it what it is, a diesel engine, rather than this ICE nonsense? An ICE is a German train…

Whilst in this instance it makes more sense to use the diesel engine moniker, ICE has become the go to method of referring to the drivetrain component as we now talk about drive trains rather than individual motive effort, rightly or wrongly.

 

[Technologist]

If the Class 450 battery trial works, maybe the 350s could go for conversion to 450s to join that programme.

Batteries are only getting better and cheaper, there is also lots of scope to lower the drag of any UK trains and the class 350's are particularly un-optimised. They could be made to go a substantial distance off the wires.

 

[HSTEd]

Batteries are only getting better and cheaper, there is also lots of scope to lower the drag of any UK trains and the class 350's are particularly un-optimised. They could be made to go a substantial distance off the wires.

Yes, if you look at pictures of modern Shinkansen you can see they have fairings around the corridor connections to render the train smooth sided - I've not seen that on any British trains that I can remember.

 

[Technologist]

Yes, if you look at pictures of modern Shinkansen you can see they have fairings around the corridor connections to render the train smooth sided - I've not seen that on any British trains that I can remember.

To put this in context Siemens were able to find a 10-15% drag reduction in their Velaro trains for their next gen Velaro Novo by fairing in bogies and carriage to carriage joins. I suspect the basic Velaro (Eurostar) is probably the most aerodynamic train on the UK network by a margin.

Looking at all the garbage on the roof of something like a class 800x shows there is plenty of scope for improving that too. Fairing everything in an using NACA ducts to provide air flow to components which need cooling is how you'd do that on anything which you cared about drag on. You would just control flow with a directional exit duct where you reversed direction.

Finally pantographs are surprisingly draggy so stowing them when not running on wires is a good idea, most trains make pretty perfunctory attempt at this.

 

[eldomtom2]

Yes, if you look at pictures of modern Shinkansen you can see they have fairings around the corridor connections to render the train smooth sided - I've not seen that on any British trains that I can remember.

But I don't think you'll see those fairings on Japanese trains built to run on conventional lines (i.e. at speeds of up to 81mph)...

 

[Technologist]

But I don't think you'll see those fairings on Japanese trains built to run on conventional lines (i.e. at speeds of up to 81mph)...

See previous context, we were talking about increasing the range of a battery assisted EMU.

Every piece of aero advantage you find is another kWh of battery you don't need to install and another route km of line you don't need to electrify.

I've not run the trades but I suspect that it will be difficult to design a piece of aero bodywork that doesn't have a net positive economic value on a BEMU.

That said a decent size EMU is blazing through about £1-2m of electricity in a year so I suspect that we probably haven't got the balance right in terms of aerodynamics on a pure cost trade as we could probably save a good portion of that cost. Certainly trains have become more aerodynamic over time but I suspect that norms and requirements (maintenance and reliability) have held back performance.

 

[sprinterguy]

Yes, if you look at pictures of modern Shinkansen you can see they have fairings around the corridor connections to render the train smooth sided - I've not seen that on any British trains that I can remember.

The LNER Coronation and West Riding coaching stock rakes of the late 1930s had these, and one APT-P half set was reportedly experimentally fitted with something similar for a brief time in 1978, but they're both fairly niche, specialised cases.

 

[The exile]

We seem to be in danger of reinventing the 4 REP + 8TC plus 33/1 solution for the 21st Century.

I must admit the notion of 350/2 plus class 68 on Scottish long distance services is quite appealing...

Why “danger”?

 

[JKF]

Class 19 plus class 91 and some mark 4s?

 

[eldomtom2]

See previous context, we were talking about increasing the range of a battery assisted EMU.

Every piece of aero advantage you find is another kWh of battery you don't need to install and another route km of line you don't need to electrify.

Three key points here. The first is that you also don't see these fairings on Japanese BEMUs, and they have quite a lot of them. The second is that electricity is not free for electrified railways, and so obviously there is an incentive for the railways to reduce the power consumption of their electric trains no matter how they get their power. Since most trains are not maximally aerodynamic, one can assume that it was judged that the benefits of increased aerodynamics were not worth the costs. The third is that while reduced power consumption does have the benefit for an BEMU of increasing its range, once its range is sufficient for the route it's deployed on the benefits of further reducing power consumption are the same as those for non-battery electric trains - i.e. reduced power costs.

 

[CW2]

Why “danger”?

Oh, just an ironic phrase.
It just seems amusing to me that we are discussing a "novel idea" that is a rehash from something we did 50 years ago.

 

[HSTEd]

Three key points here. The first is that you also don't see these fairings on Japanese BEMUs, and they have quite a lot of them.

However, those units operate at rather lower speeds than seen on the UK railway.
The fastest those units seem to be rated for is 75mph, with many being lower than this. (The EV-E301 is 40mph in service, 62mph design!)

Meanwhile, in the UK 100mph and 110mph operation is increasingly the norm.

Shinkansen sets with full fairings are being built for service on ~160mph lines at the present time.

 

[Technologist]

Three key points here. The first is that you also don't see these fairings on Japanese BEMUs, and they have quite a lot of them. The second is that electricity is not free for electrified railways, and so obviously there is an incentive for the railways to reduce the power consumption of their electric trains no matter how they get their power. Since most trains are not maximally aerodynamic, one can assume that it was judged that the benefits of increased aerodynamics were not worth the costs. The third is that while reduced power consumption does have the benefit for an BEMU of increasing its range, once its range is sufficient for the route it's deployed on the benefits of further reducing power consumption are the same as those for non-battery electric trains - i.e. reduced power costs.

From working a fair while in engineering I would never ever assume that there is a mature cost/benefit trade behind any design decision. We tend to reward engineers and engineering managers on adherence to schedule/budget so long as some basic performance specs are met rather than rigorously cost benefit everything and reward the people who deliver the highest results.

There is also the asymmetry of risk, if you spec fairings over everything and save the customer some money you will get a pat on the back. If these fairings fill up with debris in testing and need to get re-designed either during the development program of worse in service you will get crucified. So even if on average you should take these design risks people don't because the cost of the risk is rarely shared. You will rarely get negative consequences for being un-imaginative and just sticking with what has previously been done.

 

[eldomtom2]

However, those units operate at rather lower speeds than seen on the UK railway.
The fastest those units seem to be rated for is 75mph, with many being lower than this. (The EV-E301 is 40mph in service, 62mph design!)

Meanwhile, in the UK 100mph and 110mph operation is increasingly the norm.

Shinkansen sets with full fairings are being built for service on ~160mph lines at the present time.

Yes, but on the other hand the only non-Shinkansen 100mph Japanese stock, the Keisei AE Skyliner, doesn't use corridor fairings.