Could London’s New Routemaster Buses Be Fully-Electric In The City Centre?
London’s New Routemaster buses are different from nearly all the other buses built in the UK, in that Wrightbus designed them around a custom-design of chassis and series hybrid drive-train, whereas most other buses are built on a standard chassis from Volvo or another manufacturer.
These pictures show the buses from different angles.
For comparison, two of London’s other buses are shown.
Could The New Routemasters Be Fitted With Slim Pantographs?
If you look at the different profiles of the New Routemaster and the other two buses, it appears to have a thicker profile.
I very much feel that a lightweight tram pantograph could be designed to fit in the roof of a New Routemaster.
- The bus might be a few centimetres taller at most.
- I would be very surprised if there are many places in Central London, where clearance is limited.
This pantograph could be used to strategically charge the batteries.
It Would Not Be A Trolley Bus
I can remember London’s trolley buses.
Note.
- All of these modern trolley buses in Europe have two overhead wires, which are needed to handle electric currents.
- They are also designed for powering the bus as it moves along the road.
But I suspect there is a design somewhere to connect a bus to two overhead rails for charging purposes.
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.
- The floor of the New Routemaster is continuous and flat. The only steps are the stairs and up into the sets of four seats.
- 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.
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.
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.
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.
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.
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.
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.
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.
