The Anonymous Widower

Mathematics Of A Bi-Mode Aventra With Batteries

This article in Rail Magazine, is entitled Bombardier Bi-Mode Aventra To Feature Battery Power.

A few points from the article.

  • Development has already started.
  • Battery power could be used for Last-Mile applications.
  • The bi-mode would have a maximum speed of 125 mph under both electric and diesel power.
  • The trains will be built at Derby.
  • Bombardier’s spokesman said that the ambience will be better, than other bi-modes.
  • Export of trains is a possibility.

It’s an interesting specification.

Diesel Or Hydrogen Power?

Could the better ambience be, because the train doesn’t use noisy and polluting diesel power, but clean hydrogen?

It’s a possibility, especially as Bombardier are Canadian, as are Ballard, who produce hydrogen fuel-cells with output between 100-200 kW.

Ballard’s fuel cells power some of London’s hydrogen buses.

The New Routemaster hybrid bus is powered by a 138 kW Cummins ISBe diesel engine and uses a 75 kWh lithium-ion battery, with the bus being driven by an electric motor.

If you sit in the back of one of these buses, you can sometimes hear the engine stop and start.

In the following calculations, I’m going to assume that the bi-mode |Aventra with batteries has a power source, that can provide up to 200 kW, in a fully-controlled manner

Ballard can do this power output with hydrogen and I’m sure that to do it with a diesel engine and alternator is not the most difficult problem in the world.

The Mathematics

Let’s look at the mathematics!

I’ll assume the following.

  • The train is five-cars
  • The empty train weighs close to 180 tonnes.
  • There are 430 passengers, with an average weight of 80 Kg each.
  • This gives a total train weight of 214.4 tonnes.
  • The train is travelling at 200 kph or 125 mph.
  • A diesel or hydrogen power pack is available that can provide a controllable 200 kW electricity supply.

These figures mean that the kinetic energy of the train is 91.9 kWh. This was calculated using Omni’s Kinetic Energy Calculator.

My preferred battery arrangement would be to put a battery in each motored car of the train, to reduce electrical loses and distribute the weight. Let’s assume four of the five cars have a New Routemaster-sized battery.

So the total onboard storage of the train could easily be around 300 kWh, which should be more than enough to accommodate the energy generated , when braking from full speed..

I wonder if the operation of a bi-mode with batteries would be something like this.

  • The batteries would power everything on the train, including traction, the driver’s systems and the passenger facilities, just as the single battery does on New Routemaster and other hybrid buses.
  • The optimum energy level in the batteries would be calculated by the train’s computer, according to route, passenger load and the expected amount of energy that would be recovered by regenerative braking.
  • The batteries would be charged when required by the power pack.
  • A 200 kW power pack would take twenty-seven minutes to put 91.9 kWh in the batteries.
  • In the cruise the power pack would run as required to keep the batteries charged to the optimum level and the train at line speed.
  • If  the train had to slow down, regenerative braking would be used and the electricity would be stored in the batteries.
  • When the train stops at a station, the energy created by regenerative braking is stored in the batteries on the train.
  • I suspect that the train’s computer will have managed energy, so that when the train stops, the batteries are as full as possible.
  • When moving away from a stop, the train would use the stored battery power and any energy used would be topped up by the power pack.

The crucial operation would be stopping at a station.

  • I’ll assume the example train is cruising at 125 mph with an energy of 91.9 kWh.
  • The train’s batteries have been charged by the onboard generator, on the run from the previous station.
  • But the batteries won’t be completely full, as the train’s computer will have deliberately left spare capacity to accept the expected energy from regenerated braking at the next station.
  • At an appropriate distance from the station, the train will start to brake.
  • The energy of the train will be transferred to the train’s batteries, by the regenerative braking system.
  • If the computer has been well-programmed, the train will now be sitting in the station with fully-charged batteries.
  • When the train moves off and accelerates to line speed, the train will use power from the batteries.
  • As the battery power level drops, the onboard generator will start up and replace the energy used.

This sequence of operations or something like it will be repeated at each station.

One complication, is that regenerative braking is not one hundred percent efficient, so up to thirty percent  can be lost in the braking process. In our example 125mph train, this could be 27.6 kWh.

With an onboard source capable of supplying 200 kW, this would mean the generator would have to run for about eight and a half minutes to replenish the lost power. As most legs on the proposed routes of these trains, are longer than that, there shouldn’t be too much of a problem.

If it sounds complicated, it’s my bad explanation.

This promotional video shows how Alstom’s hydrogen-powered Coradia iLint works.

It looks to me, that Bombardier’s proposed 125 mph bi-mode Aventra will work in a similar way, with respect to the batteries and the computer.

But, Bombardier Only Said Diesel!

The Rail Magazine article didn’t mention hydrogen and said that the train would be able to run at 125 mph on both diesel and electric power.

I have done the calculations assuming that there is a fully-controllable 200 kW power source, which could be diesel or hydrogen based.

British Rail’s Class 150 train from 1984, has two 215 kW Cummns diesel engines, so could a five-car bi-mode train, really be powered by a single modern engine of this size?

The mathematics say yes!

A typical engine would probably weigh about 500 Kg and surely because of its size and power output, it would be much easier to insulate passengers and staff from the noise and vibration.

Conclusion

I am rapidly coming to the conclusion, that a 125 mph bi-mode train is a practical proposition.

  • It would need a controllable hydrogen or diesel power-pack, that could deliver up to 200 kW
  • Only one power-pack would be needed for a five-car train.
  • For a five-car train, a battery capacity of 300 kWh would probably be sufficient.

From my past professional experience, I know that a computer model can be built, that would show the best onboard generator and battery sizes, and possibly a better operating strategy, for both individual routes and train operating companies.

Obviously, Bombardier have better data and more sophisticated calculations than I do.

 

March 31, 2018 Posted by | Travel | , , , , , | 1 Comment

British Steel Secures Major Contract From Deutsche Bahn

The title of this post is the same as this article on Global Rail News.

I thought the article had a touch of Coals-to-Newcastle about it.

But read the article and there are a lot of things coming together to enable the order.

  • British Steel have spent a seven-figure-sum at Scunthorpe, to make the longer rails, that the Germans use.
  • Deutsche Bahn are Europe’s largest purchaser of rail.
  • The initial order is for 20,000 tonnes of rail.
  • Rails can be delivered in 120 metre lengths through the Channel Tunnel.

I should say, that I’ve read in the past, that Scunthorpe makes a quality product.

I found this video on the British Steel web site.

It all brings back memories of the time, I spent as a sixteen-year-old putting automation on heavy machines use to roll non-ferrous metals.

I doubt you get work experience like that these days!

March 15, 2018 Posted by | World | , , , , | 3 Comments

Calculating Kinetic And Potential Energies

I used to be able to do this and convert the units, manually and easily, but now I use web calculators.

Kinetic Energy Calculation

I use this kinetic energy calculator from omni.

Suppose you have a nine-car Crossrail Class 345 train.

  • It will weigh 328.40 tonnes, according to my detective work in Weight And Dimensions Of A Class 345 Train.
  • There will be 1,500 passengers at 90 Kg. each or 135 tonnes.
  • So there is a total weight of  463.4 yonnes.
  • The train has a maximum speed of 90 mph.

Put this in the calculator and a full train going at maximum speed has a kinetic energy of 104.184 kWh.

The lithium-ion battery in a typical hybrid bus, like a New Routemaster has a capacity of 75 kWh.

So if a full Class 345 train, were to brake from maximum speed using regenerative braking, the energy generated by the traction motors could be stored in just two bus-sized batteries.

This stored energy can then be used to restart the train or power it iin an emergency.

Out of curiosity, these figures apply to an Inter City 125.

  • Locomotive weight – 2 x 70.25 tonnes
  • Carriage weight – 8 x 34 tonnes.
  • Train weight – 412.5 tonnes
  • Passengers – appromiximately 700 = 63 tonnes
  • Speed – 125 mph

This gives a kinetic energy of 206.22 kWh

And then there’s Eurostar’s original Class 373 trains.

  • Weight- 752 tonnes
  • Speed 300 kph

This gives a kinetic energy of 725 kWh.

If a 75 kWh battery were to be put in each of the twenty cars, this would be more than adequate to handle all the regenerative braking energy for the train.

There would probably be enough stored energy in the batteries for a train to extricate itself from the Channel Tunnel in the case of a complete power failure.

Potential Energy Calculation

I use this potential energy calcultor from omni.

Suppose you have the typical cartoon scene, where a ten tonne weight is dropped on a poor mouse from perhaps five metres.

The energy of the weight is just 0.136 kWh.

I’ve used kWhs for the answers as these are easily visualised. One kWh is the energy used by a one-bar electric fire in an hour.

February 9, 2018 Posted by | World | , , , | Leave a comment

How To Build Railway Stations

With all the troubles caused by the failure of Carillion, it is good to report on a company, that is providing new and improved railway infrastructuresubstantially  on time and on budget.

This article on Rail Engineer is entitled VolkerFitzpatrick: Upgrading Stations.

This is the first two paragraphs.

With Network Rail’s comprehensive Railway Upgrade Plan well underway and the modernisation of Britain’s railways firmly in the spotlight, there is a growing need and expectation for first-class stations and infrastructure to accommodate growing numbers of passengers nationwide.

One business with a huge role in the modernisation programme has developed a reputation as an exceptional multi-disciplinary contractor, with extensive capabilities in civil engineering, building and rail, meeting the demands of a wide range of clients across multiple disciplines. It is this consolidated approach that has helped VolkerFitzpatrick deliver several high-profile UK railway station schemes in the last 10 years.

The article then goes on to describe how the company tackled the following stations.

It then goes on to detail the company’s omvolvement in the Lea Valley Improvement Program, which will deliver new stations at Tottenham Hale, Northumberland Park and Meridian Water.

Read the Rail |Engineer article, as it gives a good insight into design and construction.

 

 

January 21, 2018 Posted by | Uncategorized | , , , , , , , , | Leave a comment

The Electric Taxis Are Coming

London’s new electric black taxis will soon be seen on the streets.

From the pictures, I’ve seen, they could be an interesting ride.

  • There is a panoramic glass roof.
  • They are roomier, than the current black cabs and can seat six instead of five.
  • Wi-fi and charging points are standard.
  • Air-conditioning.
  • A small petrol engine is used to boost range up to nearly 400 miles.

I shall search one out for a ride.

The Times though points out an interesting point about the design. This is said.

The bigger story is LEVC will now use the technology behind the TX to build far greater volumes of hybrid electric vans, the sort that deliver all our online shopping.

That certainly is a bigger story.

A few points of my own.

Geo-Fencing

Will geo-fencing be used to ensure that in central and sensitive areas and those with high air pollution, the taxi will run on batteries only.

This would also be particularly useful with the delivery van, where delivery depots tend to be outside the centre of a city.

Wireless Charging

London’s black cabs use rabjs and only yesterday, I picked up one from the rank at the Angel.

Milton Keynes has buses that can be charged using an inductive system.

So why not install inductive charging on taxi ranks?

Online Shopping Delivery

Parcel delivery companies don’t have the best of images. Electric last-mile delivery would certainly help.

For too long, vans have just been a crude metal box, with a couple of seats and an engine at the front.

So why not design a complete system around the taxi chassis?

  • If the depot was outside the city centre, charging could be done at both the depot and on the journeys to and from the centre
  • The van could also be designed so that containers packed at the depots could be loaded for each delivery.
  • The containers could also be brought into the centre of the city at night into the main station by a purpose-designed train.
  • A sophisticated onboard computer could control the driver and the deliveries.

There is a wonderful opportunity here to develop parcel delivery systems that are truly efficient and as pollution-free as possible.

Service Vans

If I walk down my road of about 150 houses and a couple of tower blocks on any weekday during working hours, I will probably count around half-a-dozen service vans of various types for small builders, plumbers. Most have not come further than a dozen miles.

If the economics of the electric van are pitched right, I think a large proportion of these vehicles will go electric, as they often sit around for large periods during the working day.

Conclusion

I can’t wait to get a ride in one of these taxis.

December 8, 2017 Posted by | Travel | , , , , , | Leave a comment

A Heritage Class 315 Train For The Romford-Upminster Line

The Romford To Upminster Line is slated to get a brand-new Class 710 train to work the two trains per hour shuttle.

This article in London Reconnections, which is entitled More Trains for London Overground: A Bargain Never to be Repeated,   says that it is possible that this line could be served by a Class 315 train, held back from the scrapyard.

This would mean a new Class 710 train could be deployed elsewhere, where its performance and comfort levels would be more needed.

Surely, a single Class 315 train, would be enough capacity for the line and a lot cheaper than a new Class 710 train! Provided of course, that it was reliable, comfortable and could maintain the current service.

A Heritage Unit

Why not market the train, as an updated heritage unit?

  • It could be painted in British Rail livery from the 1980s.
  • It would have wi-fi!
  • It might have an information car, describing the history of the line and the area.
  • It might even have a coffee kiosk!

It would be very much a quirky train to asttract regular passengers and even tourists.

But of course, it would be run as professionally as any other train on the network.

An Educational Purpose

I feel strongly, as do many in education, that not enough people are choosing subjects like engineering as a career.

Could it be used to show that engineering and particularly rail engineering could be a worthwhile career move?

Surely, it could also be used for training staff!

A Technology Or Capability Demonstrator

Eversholt Rail Group own sixty-one of these Class 315 trains, which although they are nearly forty-years old, don’t seem to feature much on BBC London’s travel reports.

They are reportedly destined for the scrapyard, but if they were to show they could still perform after a refurbishment, they might find a paying application somewhere.

Research

Regularly, innovations are suggested for the railway, but often finding somewhere to test them can be difficult.

However, as the Romford to Upminster Line is an electrified single-track line without signalling, the line is about as simple as you can get.

So supposing a company wanted to test how a sensitive electronic instrument behaved on a moving vehicle, this could be done without any difficulty.

Conclusion

If it is decided that a Class 315 train is to be used on the Romford to Upminster Line, I believe that the service could be marketed as a quirky heritage unit, that in conjunction with its main purpose of providing a public service, could also be used for other education, training, marketing, innovation and research purposes.

Eversholt Rail Group might even shift a few redundant Class 315 trains!

November 2, 2017 Posted by | Travel | , , , | 1 Comment

A RAT Sighted At Acton Town Station

I was surprised to see an old train running through North Action station.

As it said on the side it was a Rail Adhesion Train, that I wrote about in Specialist Trains Lead The Charge Against Leaf Fall on The Piccadilly Line.

This article on Rail Engineer is entitled Leaf Fall On The London Underground and it gives more details on Rail Adhesion Trains and their use.

October 22, 2017 Posted by | Travel | , , , | Leave a comment

A First Visit To Walthamstow Wetlands

Walthamstow Wetlands opened today, so I went to take a look.

It was well worth a visit.

I shall return!

October 20, 2017 Posted by | World | , , , , | 1 Comment

Arriva London Engineering Assists In Trial To Turn Older Diesel Engine Powered Buses Green

The title of this post, is the same as that of an article on the Arriva London web site.

This sums up the project.

A new idea to turn older diesel engine buses into much more environmentally friendly vehicles has been developed by Vantage Power Ltd based in Greenford, West London in association with Ensign Ltd, the largest reseller of buses in the UK.

The new unit will start trials in July, when two of Arriva London’s 2005, Volvo B7TL, Euro 3 buses, with Alexander Dennis bodies, VLA99 and VLA100 will resume service following their conversion. The trials are fully supported by TfL.

Effectively two twelve year old buses will become hybrids with new electric drive systems.

The objectives of the project are ambitious.

The new system will be tested to see how well it performs against its targets of 40% reduction in the use of fuel, 80%+ reduction in emissions, and a cost saving for the unit which is estimated to be 80% less than a new Hybrid bus.

They are also developing a technique called geo-fence technology. This is said.

This technology, uses GPS information combined with route information, and can enable the vehicle to ensure its batteries are at full charge before entering certain areas (such as the ULEZ), or past schools, or libraries, and upon entering these areas, the engine can shut itself down and the vehicle then operate as an almost silent ZEV (Zero Emission Vehicle).

So the buses get new hybrid drives, which work as battery buses in sensitive areas and London gets cleaner air. And Arriva London gets a cashback!

I wonder how many old buses can be converted into cleaner hybrids. This conversion was on a Volvo B7TL chassis, of which there were 790 in London alone.

I also wonder if London’s current hybrid buses can have the geo-fence technology applied.

Close to my house there are six London bus routes, that go into or through the ULEX; namely routes 21, 30, 38, 56, 76 and 141 of which the 21, 38 and 76 are New Routemasters, which are modern hybrid buses. In addition, the 141  is run by seven-year-old hybrid buses. These routes would all be candidates for geo-fence technology.

October 6, 2017 Posted by | Travel | , , | 2 Comments

An Interesting Snippet From The Engineer

The Engineer is a magazine that reports on engineering and has done since 1856.

This article is entitled What’s Driving The UK’s Rail Renaissance?.

It is a worthwhile read.

This is a snippet from the section which talks about the Bombardier Aventra.

The “building blocks” of Aventra are being used for commuter train bids in India, South America and Australia.

I would take this to mean, that Bombardier have designed the train and its sub-assemblies, so that it can be put together locally.

Looking at what we know about assembly in Derby, which I reported on in How Long Will It Take Bombardier To Fulfil Their Aventra Orders?, I know or have surmised the following.

  • Bombardier are aiming for a production rate of 25 carriage a month.
  • The sides of the trains are one piece aluminium extrusions.
  • Sub-assemblies designed with suppliers feature in the design.

In addition, there has been a complete rethinking of everything about the design, manufacture and operation of the train.

The aluminium extrusions that appear to make up the sides of the train are revolutionary, with inner and outer skins and strengthening ribs between, probably being extruded in one pass, giving the following advantages.

  • High strength
  • Light weight
  • Thin train sides for greater interior width.
  • Simple, fast, affordable manufacture.

What helps is that train sides and roofs are simple shapes with a constant cross-section. Cars have much more fancy shapes.

See Wikipedia for more on extrusion.

But could it mean, that to set up a factory in say Australia, you only need to export the extruders and the handling rigs to create the body-shells for the locally-assembled trains.

Once the body-shells have been assembled, you just fit the components. Some might be manufactured locally, but other complicatedpartts like bogies, which Bombardier design in the UK, but make in Sweden, would probably be imported.

Hitachi by contrast, build the body-shells in Japan and send them by ship to their factories in Europe. How inefficient and costly is that?

Australia would get new modern trains, that were assembled locally, at a timely rate.

 

September 28, 2017 Posted by | Travel | , , , | 1 Comment