The Anonymous Widower

Buses Should Have Flat Floors

These pictures were taken inside the lower-deck of one of London’s New Routemaster buses.

Now compare them with pictures taken on the lower deck of one of London’s other hybrid buses, similar to those you see all around the UK.

Note.

  1. The floor of the New Routemaster is continuous and flat. The only steps are the stairs and up into the sets of four seats.
  2. The floor of the hybrid bus, which was built on a standard Volvo chassis has several steps.

Recently, when carrying a full bag of shopping down the stairs on the hybrid bus, the driver accelerated away and I fell and banged my knee. Because of the flat floor, it is less likely, I’d have a similar problem on the New Routemaster.

Why Does The Routemaster Have A Flat Floor?

When Wrightbus designed the Routemaster, they had a clean sheet of paper and weren’t constrained to use a proprietary chassis.

  • The 18 kWh traction battery is under the front stairs.
  • The traction motor is under the floor, in the middle of the bus.
  • The small diesel generator is mounted halfway up the back stairs.
  • The bus has full regenerative braking to the battery.

Using a standard Volvo chassis might be cheaper, but there can’t be a flat floor.

Will The Wrightbus Hydrogen Bus Have A Flat Floor?

The Wrightbus StreetDeck FCEV is the Wrightbus hydrogen bus and it has entered service in Aberdeen.

It looks to be about half flat floor, but not as good as the Routemaster.

Hopefully, I’ll ride in one soon.

February 18, 2021 Posted by | Hydrogen, Transport | , , , | 2 Comments

15 More Fuel Cell Electric Buses For UK Roads

The title of this post, is the same as that of this article on H2 View.

This is the introductory paragraph.

A further 15 fuel cell electric buses (FCEBs) are planned for the UK this year, as the country works towards its goal of deploying 4,000 zero emission buses over the next five years.

These futher points are made.

The fuel cells are 85KW heavy-duty FCveloCity®-HD fuel cell modules from Ballard Power Systems.

This will take Wrightbus’s order book for hydrogen-powered buses to fifty. all of which will be delivered this year.

Twenty buses are for London and fifteen are for Aberdeen.

I have some thoughts on the 85KW heavy-duty FCveloCity®-HD Fuel Cell Module.

This pdf file on the Ballard web site is the data sheet and this is selected data.

  • The net power is 85 kW
  • The fuel cell weighs 256 Kg.
  • It needs a coolant sub-system that weighs 44 Kg.
  • It needs an air sub-system that weighs 61 Kg.
  • It is a true zero-emission product.

It is worth looking at the power train of a New Routemaster bus, which although very different will probably give clues as to the weight that can be carried and the power and battery size needed for a full-size bus.

  • The Cummins ISBe diesel engine develops 138 kW and weighs 499 Kg.
  • The engine is mounted half-up the back stairs.
  • The Microvast Lithium Titanate battery has a capacity of 18 kWh.
  • The battery is placed under the front stairs.
  • The braking on the New Routemaster bus is regenerative.

These are some of my observations.

  • If you sit at the back of a New Routemaster bus, you can hear the engine, when it is running. On most routes in Central London, it certainly isn’t running all the time.
  • The battery doesn’t seem very large at 18 kWh.
  • The fuel cell with its sub-systems would appear to be lighter than the diesel engine, but of less power.
  • The fuel-cell won’t need the generator of the diesel bus.

I very much feel getting all the components into a standard double-decker bus will be a tight squeeze, but none of the individual components are that large or heavy.

Conclusion

I can’t wait to have my first ride in a hydrogen-powered double-decker bus.

 

June 19, 2020 Posted by | Transport | , , , | Leave a comment

Is The New Routemaster A Better Bus For COVID-19?

I went to the Angel today and rode on a New Routemaster.

It almost seemed it was a bus designed for social distancing.

  • I sat in one of the sets of four seats on the lower deck, by myself.
  • The other set, also had a single occupant.
  • The driver is safely behind a barrier and two metres from passengers.
  • Entry and exit is by rear and centre doors only.
  • The buses were designed for entry and exit at all doors.

I’d certainly be happy to travel on one of these buses.

May 4, 2020 Posted by | Transport | , , | 4 Comments

Could New Routemaster Buses Be Converted To Hydrogen Power?

London has a thousand New Routemaster buses.

They are generally liked by passengers and drivers, although some Labour politicians think they should be replaced, because of their association with Boris.

They were introduced in 2011, so with a refurbishment, I suspect that they could be in service for perhaps another ten years.

The big feature in the design is that they are genuine hybrid buses with a small Cummins engine halfway up the back stairs, a battery under the front stairs and electric drive with regenerative braking.

I do wonder though, that because of the electric transmission, that these buses could be converted to hydrogen-powered buses.

It could be a more affordable route to create a thousand new zero-carbon buses for the streets of London or any other city for that matter.

Given that Wrightbus, who built the New Routemasters, is now owned by a member of the Bamford family of JCB fame and the company is reported to be going down the hydrogen bus route, I would suspect that conversion to hydrogen is on somebody’s mind.

 

February 8, 2020 Posted by | Transport | , , , | Leave a comment

Could There Be A Bi-Mode Aventra for Commuter Routes?

The London Overground has ordered a fleet of four-car Class 710 trains.

The Gospel Oak to Barking Line is being extended to a new Barking Riverside station.

In an article in the October 2017 Edition of Modern Railways, which is entitled Celling England By The Pound, Ian Walmsley says this in relation to trains running on the Uckfield Branch, which probably has a terrain not much different to the lines in London.

A modern EMU needs between 3 and 5 kWh per vehicle mile for this sort of service.

The proposed Barking Riverside Extension is about a mile, so this could need up to 20 kWh each way.

This could easily be done with a battery, but supposing a small diesel engine was also fitted under the floor.

Would anybody notice the same 138 kW Cummins ISBe diesel engine that is used in a New Routemaster hybrid bus? I doubt it!

It is revealing to calculate the kinetic energy of a fully-loaded Class 710 train. I estimate that it is around forty kWh, if it is travelling at 90 mph.

That speed would rarely be achieved on the Gospel Oak to Barking Line.

If a Class 710 train, had only one 75 kWh battery from a New Routemaster bus, the charge levels would be as follows, as it went to Barking Riverside and back.

  • Joining the new line to go to Barking Riverside and leaving the electrification – 75 kWh
  • Starting braking for Barking Riverside station – 55 kWh
  • Stopped at Barking Riverside station, after regenerative braking, which generates perhaps 30 kWh.- 75 kWh
  • At line speed after accelerating away from Barking Riverside station – 35 kWh
  • Joining the electrified main line – 15 kWh

Note,.

  1. I have assumed that the train needs 20 kWh for the journey, but this figure will probably be lower, as the Aventra is a very efficient train.
  2. Regenerative braking is not hundred percent efficient, so that explains generating only 30 kWh. But it could be more.

It would appear that the diesel engine would not need to be used.

I come to the conclusion, that there is no need to electrify, the Barking Riverside Extension!

Here are a few other thoughts.

The Size And Number Of Batteries

The total capacity of the battery or batteries must be such, that they can handle, the maximum amount of energy that will be generated in braking.

This has the following benefits.

  • The train may not have any need to be fitted with resistors on the roof or other means to use the generated eectricity.
  • Any electrification will not need to be given the ability to handle return currents from the train.
  • The train will use less energy on a given trip.

As an engineer, I like the concept of putting a battery in all cars with traction motors.

  • Each battery will have shorter cables to where energy is used and created, which will cut losses.
  • More batteries probably improves reliability.
  • Distributing the weight might be a good thing.

I would suspect that only unmotored trailer cars might not have batteries.

Supposing a Class 710 train had three 75 kWh batteries.

This would give a capacity of 225 kWh and the following ranges on battery against energy usage in k|Wh/per mile/per car.

  • 5 kWh – 11 miles
  • 4 kWh – 14 miles
  • 3 kWh – 19 miles
  • 2 kWh – 28 miles
  • 1 kWh – 56 miles

These figures show that an efficient train is key to a longer range.

The ultimate Class 710 train might have the following.

  1. Two 75 kWh batteries per car.
  2. Energy usage of 3 kWh/per mile/per car.

This would give a range of fifty miles.

With a small and almost silent Cummins diesel engine from a New Routemaster, it could go as long as you wanted.

Should A New Routemaster Bus Diesel Generator And Battery Be Used?

Consider.

  • There are a thousand New Routemaster buses on the streets of London, so the reliability of the power train must be known very accurately.
  • The Cummins diesel engine and generator are very quiet and are only noticed on an empty bus, when they start and stop.
  • The engine and generator are under the back stairs.
  • The battery is fitted under the front stairs.

The power train doesn’t appear to be large.

Using these components would certainly be a good place to start and they could probably be easily fitted under the train.

In the rest of this post, imagine a Class 710 train with a single 75 kWh battery and a Cummins diesel and generator,

Would Be The Maximum Speed On Diesel Power Be The Same As On Electricity?

Because the battery and the diesel generator will work together, I believe this will be possible, if there is a well-programmed computer system on the train.

  • Accelerating to line speed of 90 mph will take around forty kWh, as that will be the energy of the train.
  • This will perhaps take thirty seconds in which time, the 138 kW Cummins generator, will produce just over a kWh of electricity, so the battery will provide 39 kWh.
  • The battery will be charged by electrification where it exists and regenerative braking.
  • In addition, the diesel generator could also top up the battery.
  • In the cruise, energy would need to be supplied to overcome aerodynamic losses, to climb gradients and provide train and passenger services.
  • Under braking, the regenerative braking would charge the battery.

You wouldn’t be able to run on a challenging line, but running on a fairly level line, which was perhaps twenty miles long with a dozen stations, would be a possibility.

Range on a real route, would be increased by adding extra batteries.

I suspect, Bombardier have created a sophisticated computer simulation of various train configurations and routes.

In this article in Rail Magazine, which is entitled Bombardier Bi-Mode Aventra To Feature Battery Power, a company spokesman is quoted as saying.

The bi-mode would have a maximum speed of 125 mph under both electric and diesel power.

So I’m pretty certain, a bi-mode version of a Class 710 train would have a 90 mph operating speed .

And for some easy routes on the similar-sized battery and diesel generator to that of a New Routemaster bus.

The Get-You-Home Train

Imagine a Class 710 train with a single 75 kWh battery and a Cummins generator.

Suppose power is cut to the electrification for some reason.

A normal electric train would just sit there, but the generator would cut in and using the residual energy in the battery, the train would go slowly to the next station.

With just 75 kWh and an energy usage of 3 kWh/per mile/per car, the train would go six miles.

Fast Station Stops

The keys to a fast stop at a station or a short dwell time are down to the following.

  1. Smooth, fast deceleration under regenerative braking.
  2. Efficient loading and unloading of passengers and their baggage.
  3. Fast acceleration away from the stop to regain operating speed.

Point two has nothing to do with the traction system of the train and it can be improved by good design of doors, lobbies on the train and platforms, and by better staff deployment and training.

Will the traction system be designed in a similar way to that of a New Routemaster bus?

The train’s traction, passenger, driving and other systems will be powered directly from the battery.

The battery will be charged in one of four ways.

  • From 25 KVAC overhead electrification.
  • From 750 third-rail electrification.
  • From the onboard generator.
  • From regenerative braking.

Note.

  1. A well-programmed computer system would control the whole traction system.
  2. Fast acceleration to operating speed will probably need the onboard generator or the electrification to provide a backup to the battery.
  3. The battery can probably supply more power for a short period, than an onboard generator or the electrification
  4. When the train stops in a station, the computer will ensure that the battery contain as much power as possible, so that a quick acceleration away is possible.
  5. A lot of power will have come from regenerative braking, but at times, the onboard generator  or the electrification would be used to charge the battery.
  6. At each stop, because of the limitations of regenerative braking, a certain proportion of the electrical energy will not be recovered and stored in the battery. The onboard generator or the electrification would make up the difference.

Note that the train works in the same way with an onboard generator or electrification.

The West London Orbital Railway

The proposed West London Orbital Railway will connect Hounslow and Kew Bridge stations in West London to West Hampstead and Hendon stations in North London using the Dudding Hill Line.

  • It is around twelve miles long.
  • It is electrified at the Western End using third-rail electrification.
  • There is overhead electrification in the North.
  • The middle section is not electrified.

Class 710 trains, with a diesel generator and a battery stolen from a New Routemaster bus could be able to handle the routes proposed.

Conclusion

I am led to the conclusion. that if you fitted the battery and diesel generator of a New Routemaster bus under one of the cars of a Class 710 train, you would have the following.

  • A train capable of 90 mph on diesel and electrification.
  • A useful range without electrification.

The train would need a well-programmed computer system.

The London Overground could use these trains on the Barking Riverside Extension and the West London Orbital Railway.

 

April 3, 2018 Posted by | Transport | , , , , , , | Leave a comment

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, with say four motored 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 of 55 kWh.

So the total onboard storage of the train could easily be around 200 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 | Energy Storage, Transport | , , , , , , | 6 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 | Energy, Energy Storage, World | , , , , | Leave a comment

Should London Allow All Doors Entry To Buses?

London is unique in the United Kingdom, in that nearly all of the buses have at least two doors.

The standard London buses have a front entrance and a middle exit, which gives the advantage of separating those getting on the bus and those getting off. In addition as the wheelchair ramp is under the middle door, loading and unloading wheelchair-bound passengers is a much less disruptive and much more efficient process.

Last football season in Reading, the bus had to be unloaded to get a wheelchair and its passenger on-board. It delayed the bus by about five minutes. Some fans were getting angry and started a chorus of “Why Are We Waiting”

In contrast in London, I saw an incident, where a passenger in a wheelchair needed to get on and the wheelchair space was full of babies in buggies. The ramp was put down, three buggies were immediately unloaded with no fuss, the wheelchair was pushed in and then two of the buggies were slotted in. The third was folded and carried on. It was all very civilised and in total contrast to the Reading incident. Effectively, the ramp and the pavement creates a very large lobby, which makes it easy for the wheelchair space to be rearranged. In my many trips on London buses, I’ve never seen a problem around the wheelchair bay.

But the biggest argument for a separate entrance and exit bus, was put to me by a bus driver and union rep, I met on a bus in Manchester. He said that because London buses separate entrance and exit, this pushed the low-life away from the driver and they don’t try and steal his money. London buses now don’t accept money and other drivers from places like Scotland and Liverpool have told me they want cashless buses as it cuts attacks on staff.

Additionally in London, we have the three-door Routemasters with an extra door at the rear. All doors have places to touch in with your contactless card, with one each side of the middle door.

Rarely do passengers get in at the two rear doors and not touch-in. If they do, they are often reminded by other passengers, with a knowing look.

Recently, I was at Kings Cross and two buses that get me near my house turned up at the same time; a two-door 476 and a three-door Routemaster running on route 73.

The 476 was in front and empty, but I took the 73, as I felt because it loads and unloads more quickly, it would get me home sooner.

It did! Perfectly illustrating the principle that more doors make a bus go faster.

There is probably an equal split of the type of the bus I can get home from the Angel and I feel that I’m not alone in choosing a New Routemaster if one is following a standard two-door bus. Baby buggy pushers also seem to wait, as it must be much easier to get in the middle door of a new Routemaster.

|As we are well-educated on how to use the buses here in Hackney, I wonder what would happen, if London’s two-door buses allowed entry through the middle door, by putting ticket readers at the door.

Having watched the behaviour of passengers on New Routemasters for quite a few years now, I think it would be worthwhile to try it as an experiment in certain areas of the capital.

We might find it increased the capacity and speed of London’s buses.

 

July 12, 2015 Posted by | Transport | , , | Leave a comment

Life Just Got A Whole Lot More Complicated

Well not really, but when I come home from the Angel, I usually get a 38 bus, which goes a little bit closer to my house. But now they’ve started to Routemasterise the 73 buses.

This means I can’t be sure I can distinguish the 38s, which were Routemasterised some time ago, from the thundering red herd on the Essex Road.

New Routemasters should have a top hat, as some of the old RTs of the 1950s did.

May 25, 2015 Posted by | Transport | , | Leave a comment

New Routemasters On Westminster Bridge

As I walked along the Albert Embankment, I took these pictures of New Routemasters crossing Westminster  Bridge.

They are really becoming part of the scenery.

May 14, 2015 Posted by | Transport | , | Leave a comment

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