Version: 1 Date: July 2014.

Powertrain innovation and energy efficiency (S195)

Knowledge search report prepared for:

Future Railway

Powertrain innovation and energy efficiency (S195) Page 1

Powertrain innovation and energy efficiency (S195)

Copyright notices

Copyright Rail Safety and Standards Board (RSSB) 2014.

This work comprises, in part, of a review of existing works published by others.

RSSB makes no claim on those existing works and copyright remains with the original owner.

Cover image sourced from:

http://www.unece.org/fileadmin/DAM/trans/main/temtermp/2012_2nd_Expert_Group_Meeting_Ankar

a/TEM_March_2012_Voith_emtrac_ankara.pdf

Scope of this knowledge search

As a quick knowledge search, this report provides key bibliographical references and limited

analysis. It is intended to inform decisions about the scope and direction of possible research and

innovation initiatives to be undertaken in this area. It does not provide definitive answers on this

issue; and is not intended to represent RSSB’s view on it.

The search may only include what is available in the public domain.

It has been conducted by a team with expertise in gathering, structuring, analysing both qualitative

and quantitative information, not by specialists in the field. Experts in railway operations or other

personnel in RSSB, or elsewhere, may not have been consulted due to the limited time available.

Industry and experts in this field are very welcome make observations and to provide additional

information. Please send comments to knowledgesearch@rssb.co.uk.

For further information or background to this report, please contact RSSB Knowledge and

Technology Transfer Services at knowledgesearch@rssb.co.uk.

Powertrain innovation and energy efficiency (S195) Page 2

Table of contents

OVERVIEW ...................................................................................................................................................... 3

1 ALTERNATIVE ENERGY SOURCES .................................................................................................................. 3

1.1 ALTERNATIVE FUELS .......................................................................................................................................... 3

List of selected papers ................................................................................................................................... 3

1.2 HYBRID DRIVE .................................................................................................................................................. 4

List of selected papers ................................................................................................................................... 4

2 IMPROVED ENERGY STORAGE SYSTEMS (ESSS) ............................................................................................ 6

2.1 REUSING BRAKING ENERGY ................................................................................................................................. 7

On-board storage systems - List of selected papers ...................................................................................... 7

Track-side storage systems - List of selected papers ..................................................................................... 8

2.2 ENERGY STORAGE DEVICES : CAPACITATORS AND BATTERIES ...................................................................................... 9

List of selected papers ................................................................................................................................... 9

3 MORE EFFICIENT USE OF ENERGY AND EMISSION REDUCTION .................................................................. 12

3.1 DIESEL MULTIPLE UNITS (DMUS) ..................................................................................................................... 12

Emission control Technologies - List of selected papers ............................................................................. 13

Energy efficient mechanical technologies - List of selected papers ............................................................ 14

Idle Reduction Projects - List of selected papers ........................................................................................ 14

Technical measures for energy and emission reductions - List of selected papers ..................................... 14

3.2 ELECTRIC MULTIPLE UNITS (EMUS) ................................................................................................................... 16

List of selected papers ................................................................................................................................. 16

3.3 VEHICLE WEIGHT REDUCTION ............................................................................................................................ 18

List of selected papers ................................................................................................................................. 18

Powertrain innovation and energy efficiency (S195) Page 3

Overview

This knowledge search has identified new products (TRL 8 & 9) as well as technologies (TRL 4 to 8)

on electrical and mechanical ways of improving traction efficiency in railways.

This report presents the bibliographic information of the selected papers, ordering them in the

following three categories:

1. Alternative energy sources

2. Improved energy storage systems

3. More efficient energy flow and carbon reduction

The above groupings present three broad areas on which traction efficiency improvement efforts are

concentrated in the rail industries around the world.

This paper excludes any research on efficiency benefits from improved vehicle aerodynamics and

optimised/efficient driving.

Most of the document extracts provided in the proceeding sections are exact extracts from the

original documents, and are indicated when it is the case by double quotation marks (“) in the text.

1 Alternative energy sources

1.1 Alternative fuels

Use of better quality fuels and alternative fuels such as biodiesel1, natural gas2, hydrogen (fuel cell

technology) and pure plant oil, which are available now, have the potential to significantly reduce

engine emissions. Furthermore, hydrothermally produced biodiesel and second generation biofuels

are becoming available, which will cut emissions even further.

List of selected papers

[1] BNSF Railway Company, Union Pacific Railroad Company, the Association of American

Railroads, California Environmental Associates. (2007). An Evaluation of Natural Gas-fueled

Locomotives. Available: http://www.arb.ca.gov/railyard/ryagreement/112807lngqa.pdf.

Document summary: This document provides information on past, current, and potential future efforts

to develop and use natural gas-fuelled locomotives to meet engine reliability, operational efficiency,

and air quality goals.

[2] Canadian Pacific. (2010). Biodiesel Demonstration Report. Available: http://www.cpr.ca/en/in-

your-community/environment/Documents/CP-Biodiesel-Demonstration-Final-Report-June-2010.pdf.

Document extract: “The objectives of this project were to demonstrate the viability of biodiesel use

(B5) in locomotive operations with an emphasis on cold weather operability; assess impacts on direct

to locomotive fuelling process in cold weather; and assess effects on engine components and

heating systems.”

[3] Hoffrichter. A. (2013). Hydrogen as an energy carrier for railway. Available:

http://etheses.bham.ac.uk/4345/1/Hoffrichter13PhD.pdf.

1 http://biodieselmagazine.com/articles/7859/steaming-ahead-to-a-better-fuel 2 https://nabe.m3ams.com/Document/Download/23709001

Powertrain innovation and energy efficiency (S195) Page 4

Document summary: A PhD thesis on the use of hydrogen for railway traction.

[4] Kumar. S, Jae Hyun Cho, Jaedeuk Park,Il Moon. (2013). Advances in diesel–alcohol blend sand

their effects on the performance and emissions of diesel engines. Available:

http://www.sciencedirect.com/science/article/pii/S1364032113000488.

Document extract: “Alcohols such as methanol, ethanol and butanol are competitive alternative fuels

due to their liquid nature, high oxygen contents, high octane number and their production from

renewable biomass. In this review, the fuel properties of these alcohols are compared with

conventional gasoline and diesel fuel. The comparison of fuel properties represents that butanol has

the potential to overcome the problems associated with the use of methanol and ethanol. Progresses

of their production from different sources are also introduced.”

[5] Rowan University. (2009). Evaluation of Emissions and Performance of NJ TRANSIT Diesel

Locomotives with B20 Biodiesel Blends. Available:

http://www.nj.gov/dep/sage/docs/biodiesel_njtransit_fullreport.pdf.

Document extract: “This report quantifies the exhaust emissions and performance characteristics of

20% soy methyl ester biodiesel blends (B20) in diesel locomotives representative of the NJ TRANSIT

commuter fleet.”

[6] RSSB. (2013). Use of Hydrogen as an energy store (S159). Available:

http://www.sparkrail.org/Lists/Records/DispForm.aspx?ID=14737.

Document summary: This report is a review of hydrogen as an energy store for rail traction.

[7] RSSB. (2014). Natural gas for freight trains (S187). Available:

http://www.sparkrail.org/Lists/Records/DispForm.aspx?ID=15181.

Document summary: This report explores technologies developed by suppliers and trials undertaken

by train operators around the world to start to determine whether a transition from diesel to natural

gas is feasible and beneficial.

1.2 Hybrid drive

In order to further increase the energy savings from diesel engines, hybrid technologies can be

utilised, where on-board energy storage systems (batteries or capacitors) are used to complement

diesel engines.3 4 This technology can be integrated with a regenerative braking system to convert

the kinetic energy generated during braking back into electricity (see Section 2 on improved energy

storage systems).

List of selected papers

[1] BNSF Railway Company. (2012). Hydrogen fuel cell hybrid locomotives. Available:

http://www.google.com/patents/US8117969. US Patent: US 8117969 B1.

3 http://www.economist.com/node/17791989 4 http://www.mtu-online.com/fileadmin/fm-dam/mtu-global/technical-info/case-

studies/3082571_MTU_Rail_CaseStudy_HybridPowerpack_2013.pdf

Powertrain innovation and energy efficiency (S195) Page 5

Document extract: “Patent for a hydrogen hybrid locomotive including a set of batteries for driving a

plurality of electric traction motors for moving the locomotive along a set of railroad rails and a fuel

cell power plant for charging the set of batteries and driving the electric traction motors. The fuel cell

power plant includes at least one fuel cell power module for generating electrical current by reacting

hydrogen fuel and oxygen from intake air, the amount of electrical current being proportional to an air

mass flow of the intake air. An air system selectively provides an air mass flow to the fuel cell module

to generate an amount of electrical current required for corresponding operating conditions of the

locomotive. A cooling system cools the at least one fuel cell power module in response to the amount

of current being generated.”

[2] East Japan Railway Company. (2011). Development of Catenary and Battery Powered Hybrid

railcar system. Available: http://www.railway-research.org/IMG/pdf/b6_masatsuki_ichiro.pdf.

Document extract: “JR East has been developing "Catenary and Battery-powered hybrid railcar

system" to decrease environmental impact by diesel railcars that have been operated in non-

electrified lines. The development of the experimental car and battery charging system on ground

was started 2008, the experimental railcar was completed Oct. 2009 and we tested concerning to

subjects of running performance, control system, and battery characters. Based on the classification

of the circuits, we constructed the battery charging facilities last year. From Feb. 2011, we started

total system performance test of the catenary and battery-powered hybrid railcar system, using both

of charging facilities and experimental railcar. This paper shows development method and typical

result of these test programs.”

[3] Hitachi. (2008). Practical Application of a Hybrid Drive System for Reducing Environmental Load.

Available: http://www.hitachi.com/rev/pdf/2008/r2008_01_003.pdf.

Document extract: “For DMUs running in non-electrified regions, on top of the fact that regenerative

braking cannot be applied as a system for direct drive by diesel engine, reduction of NOx and CO2

gases contained in exhaust is a challenge. Accordingly, we have practically applied a hybrid drive

system that can reduce environmental load by means of applying secondary batteries to store

regenerative energy and by running the engine at maximum rotational frequency (at which efficiency

is high) and switching to electrical energy.”

[4] Japan Freight Railway, Toshiba. (2011). Electrical Equipment used in diesel hybrid shunting

locomotive HD300. Available: http://www.sparkrail.org/Lists/Records/DispForm.aspx?ID=2833.

Document extract: “Japan Freight Railway Co., Ltd. and Toshiba have jointly developed a series

hybrid shunting locomotive, type HD300, to replace the diesel hydraulic locomotive type DE10,

mainly used for shunting freight cars in freight yards, and have the sufficient field test results by

reducing toxic exhaust gases, lowering the exterior noise level, and reducing CO2 emissions.”

[5] Rasul M. G.; Patel A.; Cole C.; Sun Y.; Spiryagin M.; Godber T.; Hames S.. (2013). Train motive

power technologies: A review on existing and emerging (Hybrid) technologies. Available:

http://www.sparkrail.org/Lists/Records/DispForm.aspx?ID=12447.

Document extract: “In this paper, the existing traction technologies used to propel locomotives are

reviewed and discussed first. Included are diesel-electric, diesel-hydraulic and electric traction

technologies and their advantages and disadvantages. The energy storage devices (such as

Powertrain innovation and energy efficiency (S195) Page 6

batteries, supercapacitors and flywheels) for railway applications that can be used to store and reuse

regenerative braking energy are then discussed. Furthermore, the emerging (hybrid) locomotive

traction technologies which include diesel based hybrid traction and fuel cell based hybrid traction

are reviewed and discussed. Finally, the challenges that can be further researched regarding

applications of hybrid traction technologies are presented.”

[6] Vehicle Projects Inc; ERDC-CERL; BNSF Railway Company. (2011). Hydrogen fuel-cell

locomotive: switching and power-to-grid demonstrations. Available:

http://www.sparkrail.org/Lists/Records/DispForm.aspx?ID=2914.

Document extract:” An industry-government consortium has developed a prototype zero-emissions,

hydrogen-fuelled, fuel-cell hybrid switch locomotive for urban and military-base rail applications. With

130 t weight and maximum power of 1.5 MW from its proton-exchange membrane fuel-cell prime

mover and auxiliary traction battery, the hybrid locomotive is currently the heaviest and most

powerful fuel-cell land vehicle. The observed mean thermodynamic efficiency of the power plant is 51

%. Compressed hydrogen fuel is stored in carbon-fibre composite tanks (maximum pressure of 35

MPa) located at the roofline.”

[7] Vehicle Projects LLC. (2007). System design of a large fuel cell hybrid locomotive. Available:

http://www.sciencedirect.com/science/article/pii/S0378775307015856.

Document extract: “Fuel cell power for locomotives combines the environmental benefits of a

catenary-electric locomotive with the higher overall energy efficiency and lower infrastructure costs of

a diesel-electric. A North American consortium, a public–private partnership, is developing a

prototype hydrogen fuelled fuel cell-battery hybrid switcher locomotive for urban and military-base rail

applications.”

[8] West Japan Railway Company. (2011). Development of mild hybrid system for diesel railcar.

Available: http://www.railway-research.org/IMG/pdf/a1_kobayashi_makoto.pdf.

Document extract: “Generally in Japan, the diesel railcar used in non-electrified section is powered

by diesel engine, and propulsion power is transmitted to wheels by hydraulic transmission. So the

diesel railcar cannot use regenerative brake like electric railcar. But the reduction of energy

consumption is demanded in late years. We developed mild hybrid system for diesel railcar from the

energy transmission efficiency point of view, use regenerative electric power to auxiliary devises. We

confirmed the effect of this system both running test and simulation.”

2 Improved energy storage systems (ESSs)

The advances in both power electronics and energy storage technologies have enabled ESSs to

become a good option for rail traction purposes, especially for reusing regenerated braking energy

on the railways.

A regenerative braking system captures braking energy and stores it in the form of electricity; rather

than allowing it to be transferred to heat via the brakes and dissipated into the atmosphere. The

stored energy is either stored on-board the train or stored in track-side equipment.

Powertrain innovation and energy efficiency (S195) Page 7

2.1 Reusing braking energy

On-board ESSs permit rail vehicles to temporarily store their own braking energy and reutilise it in

the next acceleration phases. In contrast, trackside ESSs collect energy from any braking train in the

near area and release it when demanded by other accelerating vehicles. If properly utilised, both on-

board and wayside (e.g. EnerGstor from Bombardier5) ESSs may lead to considerable traction

energy savings on the railway; moreover, they may contribute to stabilising network voltage and to

reduce the power consumption peaks. Additionally, on-board energy systems may provide a certain

degree of autonomy for catenary-free services. In general, on-board ESSs operate with higher

efficiency than wayside ESSs owing to the absence of line losses. However, they typically require

large space on vehicles and introduce a considerable increase of weight, which may hinder their

installation in existing rolling stock. In turn, stationary ESSs present fewer weight and space

restrictions and their installation and maintenance do not affect services. Composite flywheels6 also

offer attractive features for energy recovery and storage in railway.7

Both pure electric or diesel-electric trains can utilise regenerative braking.

On-board storage systems - List of selected papers

[1] Central Japan Railway Co. (2010). Traction Systems Using Power Electronics for Shinkansen

High-speed Electric Multiple Units. Available:

http://ieeexplore.ieee.org/xpl/login.jsp?tp=&arnumber=5542320&url=http%3A%2F%2Fieeexplore.iee

e.org%2Fxpls%2Fabs_all.jsp%3Farnumber%3D5542320.

Document extract: “This paper presents advantageous features of the distributed traction systems, or

Electric Multiple Units, and application of power electronics technology to the Shinkansen High-

speed train. The EMUs have many advantages such as the energy saving by regenerative brake,

high-speed running on steep gradient routes with high adhesive force, and others. Historically, the

Japanese high-speed train system, Shinkansen, has employed the EMU system, and furthermore, it

has adopted the AC regenerative braking system and the asynchronous motor driving system for the

traction system since the Series 300 in 1990. The current flagship Series N700 Shinkansen train

employs the train-draft-cooling power converter with the low-switching-loss IGBT. This contributes to

realizing a quarter of weight/power ratio of the traction system and a half of energy consumption,

compared with the Series 0, the first-generation Shinkansen. In this paper, as a future development

of innovative lightweight technologies, a permanent magnet synchronous traction motor (PMSM) is

also introduced.”

[2] Hitachi. (2010). Energy Storage System for Effective Use of Regenerative Energy in Electrified

Railways. Available: http://www.hitachi.com/rev/pdf/2010/r2010_01_104.pdf.

Document extract: “Hitachi is working on the development of energy-saving systems for rolling stock

that use lithium-ion batteries to help reduce the environmental impact of railway systems. Two issues

associated with regenerative braking are regenerative braking under light load conditions and limits

on performance due to motor characteristics, and in response Hitachi has developed respectively an

absorption of regenerative electric power function and a regenerative brake with effective speed

extended function, proposed an efficient regeneration management system for determining when to

operate these functions, and is currently commercializing these technologies. For the function to

absorb regenerative electric power, Hitachi has developed the wayside B-CHOP system and on-

5 http://www.bombardier.com/content/dam/Websites/bombardiercom/supporting-documents/BT/Bombardier-

Transportation-ECO4-EnerGstor-EN.pdf 6 http://www.railway-technology.com/contractors/electrification/williams-advanced-engineering/ 7 http://www.railway-technology.com/contractors/electrification/kinetic-traction-systems/

Powertrain innovation and energy efficiency (S195) Page 8

board sequential regenerative brake system to provide systems that are appropriate to the line and

other operating conditions where the system is to be installed. Hitachi will continue to enhance the

functions of its energy-efficient systems to meet diverse customer needs.”

[3] Hitachi. (2012). Current and Future Applications for Regenerative Energy Storage System.

Available: http://www.hitachi.com/rev/pdf/2012/r2012_07_111.pdf.

Document extract: “Hitachi has developed a system for the storage of regenerative power that uses

the same lithium-ion batteries as hybrid cars to store and reuse this energy in trains. The system was

commercialized in 2007. In some cases, the installation of this system produced savings of more

than 10% in power consumption. Hitachi intends to accelerate the deployment of this system to

reduce railway power consumption in Japan and other markets.”

[4] Rail Technical Research Institute. (2012). Performance of Linear Motor Type Rail Brake Using

Roller Rig Test Bench. QR of the RTRI. Volume 53, No.1. Available:

https://www.jstage.jst.go.jp/article/rtriqr/53/1/53_1_41/_article.

Document guide: “Linear Induction motor brake combines actively switched eddy current induction

coils with energy harvesting induction coils in the form of a regenerative linear induction motor. This

form of braking has recently been the subject of significant study at the Rail Technical Research

Institute in Japan.”

[5] West Japan Railway Company. (2011). Development of diesel hybrid vehicle braking systems.

Available: http://www.sparkrail.org/Lists/Records/DispForm.aspx?ID=3729.

Document abstract: “In West Japan Railway Company “JR West”, braking systems of diesel vehicle

consist of pneumatic brake, engine brake. Regenerative brake and engine brake act because the

diesel hybrid vehicle is directly connected of an engine and an induction motor. Therefore, we

developed new diesel hybrid vehicle braking systems cooperated with pneumatic brake and

regenerative brake and engine brake. Diesel hybrid vehicle braking systems developed by authors

allowed smooth braking with small longitudinal vibration acceleration of the body.”

Track-side storage systems - List of selected papers

[1] ADIF; CEDEX; CIEMAT. (2008). A kinetic energy storage system for railways applications.

Available: http://www.uic.org/cdrom/2008/11_wcrr2008/pdf/PS.2.5.pdf.

Document abstract: “This paper shows the design, development and tests of a Kinetic Energy

Storage System (KESS) developed jointly by ADIF and CEDEX to be applied in a rail electrical

substation. The basic behaviour of such a system is to store the braking energy of trains in a rotating

flywheel and to give energy back once it is needed to give traction power to the same or other trains

fed by the same catenary. CEDEX work is focused on the design and development of the KESS unit

itself, and ADIF is working on analysing the most appropriate place to install the system from the

point of view of optimizing the energy saving, as well as the auxiliary systems needed to install the

KESS unit it in a rail substation.”

[2] Bombardier Transportation. (2013). EnerGstor – A New Wayside Energy Storage System.

Available: http://www.sparkrail.org/Lists/Records/DispForm.aspx?ID=12413.

Powertrain innovation and energy efficiency (S195) Page 9

Document extract: “BOMBARDIER EnerGstor is a new wayside energy storage system based on

ultracapacitor technology, which captures and stores the otherwise unusable regenerated braking

energy and recycles it back into the system. This paper will cover the system concept and the main

features of EnerGstor technology; test results from a 1kWh prototype unit installed at Bombardier’s

Kingston (Ontario, Canada) test track; and a case study.”

[3] Kawasaki Rail Car Inc., New York City Transit. (2011). Test Results of a High Capacity Wayside

Energy Storage System Using Ni-MH Batteries for Electric Railway at New York City Transit.

Available:

http://ieeexplore.ieee.org/xpl/login.jsp?tp=&arnumber=5754859&url=http%3A%2F%2Fieeexplore.iee

e.org%2Fxpls%2Fabs_all.jsp%3Farnumber%3D5754859.

Document extract: “Based on the conclusions, it has been confirmed that the application of BPS

(Battery Power System) with GIGACELL batteries (a high-capacity battery based on nickel-metal

hydride (Ni-MH) technology) connected directly to the railway traction power line makes it possible to

reduce energy consumption through an effective use of braking regenerative power and that BPS

responds quickly to discharging during powering as well as to charging by regenerative power during

braking.”

[4] Metro De Bilbao, INGETEAM Traction. (2011). Kinetic energy recovery on railway systems with

feedback to the grid. Available: http://www.railway-research.org/IMG/pdf/a5_romo_asier.pdf.

Document extract: “The solution presented in this paper deals with the design strategy and topology

of a new converter developed for a 1500Vdc catenary subway traction system. The recovery system

works connected to an already existing transformer in the substation, minimizing the investment

needed.”

2.2 Energy storage devices : capacitators and batteries

Regarding the technologies available for ESSs in railways, Electrochemical Double Layer Capacitors

(EDLCs)8 are suitable options. EDLCs offer high power density, fast response, high cycle efficiency

and long lifecycle, features that make this technology the most widely used in urban rail applications

(an example of use in Germany9) so far. However, their energy density is very low, being replaced by

(or combined with) high specific power Li-ion, such as StartPac’s Li64RR lithium ion 64 V battery10,

or NiMH batteries in systems providing high degrees of autonomy on non-electrified lines; examples

include trams in China11 and the United States12.

List of selected papers

[1] Bombardier Transportation. (2004). Energy storage on board of DC fed railway vehicles.

Available:

http://ieeexplore.ieee.org/xpl/login.jsp?tp=&arnumber=1355828&url=http%3A%2F%2Fieeexplore.iee

e.org%2Fiel5%2F9371%2F29757%2F01355828.

8 http://www.uic.org/cdrom/2006/wcrr2006/pdf/307.pdf 9 http://www.eltis.org/index.php?id=13&lang1=en&study_id=1931 10 http://www.railwaygazette.com/news/technology/single-view/view/lithium-loco-battery.html 11 http://www.railwaygazette.com/news/urban/single-view/view/guangzhou-supercapacitor-tram-unveiled.html 12 http://www.railway-technology.com/news/newssiemens-install-sitras-ses-energy-storage-unit-trimet-light-

rail-line

Powertrain innovation and energy efficiency (S195) Page 10

Document extract: “The proposed energy storage on board of a DC-railway vehicle leads to a big

step in the reduction of consumed energy. Up to 30% energy saving are expected in a light rail

vehicle, at the same time reducing the peak power demand drastically. In addition, with the energy

storage an operation without catenary could become reality, which was successfully demonstrated

with the prototype light rail vehicle driving with switched off pantograph. This prototype vehicle is in

passenger operation since September 2003, the implemented software is optimized on energy

savings and first experience is very promising.”

[2] Bombardier Transportation. (2008). Energy Storage System with UltraCaps on Board of Railway

Vehicles. Available: http://www.uic.org/cdrom/2008/11_wcrr2008/pdf/R.3.4.3.2.pdf.

Document extract: “The on board energy storage system with Ultracaps for railway vehicles

presented in this paper seems to be a reliable technical solution with an enormous energy saving

potential. The measured traction energy saving of approximately 30% confirmed fully the former

calculations. Very promising are energy storage applications in propulsion systems of Diesel-

Electrical Multiple Units (DEMUs). These vehicles lack possibilities to use the braking energy of the

train. Energy storage systems on board of DEMUs bring high fuel savings together with the

corresponding emission reduction. On top of that the energy storage leads to a booster effect – extra

power during acceleration from the storage, by adding the limited weight of the MITRAC Energy

Saver.”

[3] Hitachi. (2012). Energy-saving Technology for Railway Traction Systems Using Onboard Storage

Batteries. Available: http://www.hitachi.com/rev/pdf/2012/r2012_07_104.pdf.

Document extract: “The first application for on-board storage batteries came with the

commercialization of series hybrid drive systems that reduced the fuel consumption of diesel trains.

Storage battery control has also been used for the absorption of regenerative electric power and to

implement the regenerative brake with extended effective speed. Further progress has since led to

the development of an efficient regeneration system for making effective use of electric power. Now,

Hitachi has conducted operational trials of the regenerative brake with extended effective speed

using storage batteries to boost the DC voltage at the inverter input, achieving an increase in

regenerative electric power of up to 12.5% (for a 300-V boost). In the future, Hitachi intends to

encourage the wider use of on-board storage batteries by achieving a good balance of return on

investment, and by working on new energy-saving technologies that are closely aligned with

customer needs.”

[4] Kawasaki Heavy Industries, Ltd. (2008). The development of low floor battery-driven LRV

“SWIMO”. Available: http://www.uic.org/cdrom/2008/11_wcrr2008/pdf/R.2.2.3.2.pdf.

Document extract: “This paper describes the development of “SWIMO”. “SWIMO” is a barrier-free

LRV, friendly to everyone, which has been developed to minimize the height differences between

stations and the vehicle cabin floors to the utmost limit. In addition, SWIMO has battery charging and

discharging system with on-board rechargeable nickel-metal-hydride (Ni-MH) battery. SWIMO

generates power on reducing speed, which charges battery so that it can power the vehicle and

utilities. This greatly increases energy efficiency of LRV.”

Powertrain innovation and energy efficiency (S195) Page 11

[5] Railway Technical Research Institute. (2011). The evaluation of endurance running tests of the

fuel cells and battery hybrid test railway train. Available:

http://www.sparkrail.org/Lists/Records/DispForm.aspx?ID=2834.

Document abstract: “For the purpose of an environmental burden reduction and an improvement of

energy efficiency, RTRI have been developing fuel cells railway train since the year 2001. In the year

2006, we installed the 100kW class proton exchange membrane fuels cells in our test railway train

and executed running tests on our test line by one car. In the year 2008, in order to improve energy

efficiency further, we developed the lithium-ion battery system to absorb regenerative energy and to

increase an accelerating power, the DC/DC converter for charging and discharging the battery. In the

year 2009, we installed these equipment in another car and composed a fuel cells and battery hybrid

test railway train with these two cars. Through running tests, we evaluated fuel cells’ durability and so

on.”

[6] RSSB. (2013). Battery technology scanning 2013 (S152). Available:

http://www.sparkrail.org/Lists/Records/DispForm.aspx?ID=14738.

Document summary: In the recent years, developments in battery technology has seen public

transport manufacturers testing new vehicles that use battery for traction. This horizon scanning

examines trends, benefits and applications of new and innovative storage devices for railways.

[7] Siemens AG. (2009). New mobile energy storage system for rolling stock. Available:

http://ieeexplore.ieee.org/xpl/login.jsp?tp=&arnumber=5278736.

Document extract: “The introduction of the new Hybrid Energy Storage system Sitras® HES based

on a new electrical connection to the common power supply voltage offers extended possibilities of

the operation mode driving without overhead contact line. Consequently, increasingly arising

requirement of customers due to aesthetical, environmental or operational reasons can be satisfied

by the technology of on-board energy storage units. For both operating modes – energy-efficient

operation and operation without overhead contact lines valuable results and experiences in revenue

service at MTS (Metro Transportes do Sul, S.A.) south of Lisbon, Portugal demonstrates the benefits

of the new connection concept and the new energy storage system certified according to BOStrab

(German Construction and Operating Code) by TÜV Süd GmbH, Germany.”

[8] Transp. Global Solutions, Alstom Transport. (2010). STEEM: ALSTOM and RATP experience of

supercapacitors in tramway operation. Available:

http://ieeexplore.ieee.org/xpl/login.jsp?tp=&arnumber=5729152.

Document extract: “Supercapacitors have a very high power density that enables quick recharge

during a small period of time. This technology allows both energy optimisation and autonomy from

the overhead line. The STEEM project consisted in the development of an on-board energy storage

system made of supercapacitors. The ESS has been roof-mounted on a RATP Citadis, extensively

tested, certified by an independent agency and is running in revenue service on Paris tramway line

T3. The energy consumption of the demonstration vehicle has been reduced. The energy storage

system also enables the tramway to run without catenary. Relying solely on its on-board energy, the

vehicle can run from one station to the next one. For this kind of operation, the operational

environment appears to be of paramount importance, and shows the benefit of associating a

manufacturer and a public operator for this kind of research project.”

Powertrain innovation and energy efficiency (S195) Page 12

[9] West Japan Railway Company, GS Yuasa Corporation. (2008). Study for the Degradation of the

Large-Sized Lithium-Ion Batteries for the Railway Power Storage Systems. Available:

http://www.uic.org/cdrom/2008/11_wcrr2008/pdf/PS.2.33.pdf.

Document extract: “We studied cycle life performance for Large-Sized Lithium-Ion batteries for the

accelerated test at various temperatures, and then we brought them to the real field for the railway

power storage systems. In summary, we succeeded to predict life performance of the large-sized

lithium-ion batteries for the railway power storage system. Life performance was calculated over 10

years in the field condition, so we suggested these batteries had enough life performance for this

system.”

3 More efficient use of energy and emission reduction

For diesel multiple units (DMUs) and electric multiple units (EMUs), energy losses in on-board

traction equipment are predominantly due to inefficiencies in the motors or engines themselves,

whereas losses in power converters are relatively minor. Hence, the greatest improvements in

traction efficiency can be achieved by using more efficient motors or engines.

3.1 Diesel Multiple Units (DMUs)

In DMUs, the diesel engine is used to generate electricity, which then drives the traction motors to

move the wheels. There is no mechanical connection between the locomotive engine and wheels.

The main improvements in locomotives have been to the supervisory and power controls, including

electronic fuel injection control, traction motor control and engine cooling. Improvements in engine

technology have followed the broader diesel engine industry.13 This includes improvements in

injector design and controls, combustion chamber, turbochargers, inlet air cooling, and engine

system cooling. These improvements in electric power controls and engines have brought about

higher energy efficiency, higher power, and lower emissions.14 The newer engines also have reduced

the amount of fuel consumed when idling.15

More efficient common-rail diesel engines are being developed which feature technologies such as

high pressure fuel injection combined with turbochargers16 and start/stop technology17, which are

commercially available (e.g. Lat-Lon’s Automatic Engine Start / Stop for Locomotives18).

Achieving a higher compression pressure in the cylinder at the moment of fuel injection can reduce

the ignition delay, which is an important factor in the formation of pollutant particles. By using a

turbocharger the total mass of intake air increases, which results in a lower combustion temperature.

These effects reduce the formation of pollutant particles and reduce fuel consumption. ABB’s

turbochargers are an example of what is available in the industry19.

13

http://www.cdc.gov/niosh/mining/UserFiles/workshops/dieselaerosols2012/NIOSHMVS2012Tier4Technology

Review.pdf 14 http://alaskarailroad.com/Portals/6/pdf/projects/2011_01_05_Locomotive_Overhaul_PROJ.pdf 15 http://www.northeastdiesel.org/pdf/LocomotiveIdleReductionOptions.pdf 16 http://www.railway-technology.com/contractors/overhaul/drivetrain-power/ 17 http://www.gwrr.com/about_us/community_and_environment/gwi_green/genset_locomotives 18 http://www.railway-technology.com/contractors/vehicle/lat-lon/press7.html 19

http://www05.abb.com/global/scot/scot208.nsf/veritydisplay/cb083e6b3aa75f80c1257a7d004628e7/$file/ABB

TC_BRO1190_TPR.pdf

Powertrain innovation and energy efficiency (S195) Page 13

A turbocharger can be effectively combined with an inter-cooler that cools the air before it enters the

cylinder. Through lowering the temperature, the air mass flow into the cylinder can be increased (cold

air has a higher density), which in turn reduces exhaust pollution.

Moreover, nitrogen oxide emissions can be reduced using internal engine technology by cooling

some of the exhaust gas, which is then redirected back into the charge air. This results in a reduction

of the combustion temperature and hence less nitrogen oxide is produced. This process is known as

Exhaust Gas Recirculation (EGR) and is one of the principal methods used to reduce nitrogen oxide

emissions from diesel engines. 20 21

Emission control Technologies - List of selected papers

[1] CleanER-D. (2010). D6.1.1 State of the Art Study Report of Low Emission Diesel Engines and

After-Treatment Technologies in Rail Applications. Available: https://secure.cnc.it/cleaner-

d/Docs/CLD-D-APT-004-06.pdf. Last accessed 30th May 2014.

Document extract: “The aim of this report is to review the state of the art in Diesel emission control

technologies in the application areas where it has been pioneered so far, mainly road going vehicle

Diesel engines, considering the potential for transfer of these technologies to rail applications. The

review covers all the technology areas in which developments have led to emissions reductions for

Diesel engines, including Diesel combustion, air management, Diesel fuel injection, exhaust gas

recirculation (EGR), and exhaust gas after-treatment technologies. Also this report includes is a

review of clean Diesel engine technologies currently being used in rail vehicles.”

[2] Manufacturers of Emission Controls Association. (2009). Retrofitting Emission Control for Diesel-

Powered Vehicles. Available:

http://www.meca.org/galleries/files/MECA_diesel_retrofit_white_paper_1009.pdf. Last accessed 30th

May 2014.

Document summary: This document has been prepared as an overview on emission control

technologies.

[3] Manufacturers of Emission Controls Association. (2014). Case Studies of the Use of Exhaust

Emission Controls on Locomotives and Large Marine Diesel Engines. Available:

http://www.meca.org/resources/Loco_Marine_Case_Studies_update_0114.pdf. Last accessed 30th

May 2014.

Document extract: “Many of the locomotive and marine diesel engine projects discussed in this report

have been focused on demonstrating the feasibility of applying verified, on-road retrofit emission

control technology on locomotive and marine engines and quantifying the diesel emission reductions

achieved. Many of the projects have been initiated by the state, local, and federal agencies to

promote interest in retrofitting locomotive and marine engines and facilitate other retrofit projects that

may build on the successes and challenges learned from previous projects.”

20 http://proceedings.asmedigitalcollection.asme.org/proceeding.aspx?articleid=1721027 21 http://www.mtu-online.com/fileadmin/fm-dam/mtu-global/technical-info/white-

papers/131218_WhitePaper_Abgasrueckfuehrung_EN.pdf

Powertrain innovation and energy efficiency (S195) Page 14

Energy efficient mechanical technologies - List of selected papers

[1] General Electric Company. (2010). Common fuel rail fuel system for locomotive engine. Available:

http://www.google.com/patents/EP1904739B1?cl=en. EP Patent: EP 1904739 B1.

Document summary: This specification relates generally to the field of railroad locomotives and more

generally to a common rail fuel system for a diesel engine of a railroad locomotive.

[2] Siemens AG. (2008). Syntegra® –The intelligent Integration of Traction, Bogie and Braking

Technology. Available: http://www.uic.org/cdrom/2008/11_wcrr2008/pdf/R.1.1.3.1.pdf. Last accessed

30th May 2014.

Document extract: “With Syntegra technology, Siemens opens new horizons for metro, underground

and commuter trains. Syntegra integrates traction, bogie and brake systems to a compact powered

bogie concept, which will enable higher efficiency, lower dead weight and reduced emissions than

any other conventional systems. In addition this new generation of powered bogies decrease life

cycle cost. The integration and moreover the technological advances within the three systems bring

about many synergies and advantages compared with today's state of the art. In the Siemens test

facility in Wegberg-Wildenrath and in Munich's metro network the prototype testing is on its very

promising way. This paper presents this rather radical or disruptive innovation.”

Idle Reduction Projects - List of selected papers

[1] Southwest Clean Air Agency. (2005). Vancouver, WA Switchyard Locomotive Idle Reduction

Project. Available: http://www.epa.gov/smartway/forpartners/documents/rail/documents/vancouver-

locomotive.pdf. Last accessed 30th May 2014.

Document extract: The “Vancouver Switchyard Diesel Locomotive Engine Idling Retrofit” project

installed Kim Hotstart’s diesel driven heating system on 3 diesel locomotive engines in the

Vancouver, WA to examine benefits from the idle reduction technology.

[2] U.S. Environmental Protection Agency. (2004). Case Study: Chicago Locomotive Idle Reduction

Project. Available:

http://www.epa.gov/smartway/forpartners/documents/rail/documents/420r04003.pdf. Last accessed

30th May 2014.

Document extract: “The installation and use of a combined “Diesel Driven Heating System” and a

“SmartStart System” on a locomotive switch yard engine reduced overall idling times by 80%. This

resulted in an annual reduction of 12,738 gallons of diesel fuel over 298 in-service days or 42.7

gallons per day. If a railroad’s average locomotive availability per year is 92% or 335 days (industry

average), annual fuel savings would be 14,339 gallons. At $1.00 per gallon of diesel fuel, the

combined savings from the idle reduction technology has a reasonable payback of about 2.5 years.

In addition to fuel savings, the technology reduces noise, oil consumption, maintenance costs, and

extends engine life.”

Technical measures for energy and emission reductions - List of selected papers

[1] AEA Technology, UIC. (2005). Technical and operational measures to improve the emissions

performance of diesel rail. Available: http://www.uic.org/download.php/environnement/2006-02-

diesel-study-wp2.pdf. Last accessed 30th May 2014.

Powertrain innovation and energy efficiency (S195) Page 15

Document extract: “Summarises the range of technical measures for emissions reductions initially

identified for consideration for potential rail application. Subsections provide short descriptions of the

measures and a summary of issues identified with regards to possible application in rail vehicles,

drawing on any rail experiences in their utilisation, where available.”

[2] Australian Department of Resources, Energy and Tourism. (2012). FUEL FOR THOUGHT

Identifying potential energy savings in the Australian road and rail sectors. Available:

http://eex.gov.au/files/2012/03/Fuel-for-Thought.pdf. Last accessed 30th May 2014.

Document summary: Pages 45-67 present energy efficiency opportunities for rail transport.

[3] California Environmental Protection Agency. (2009). Technical Options to Achieve Additional

Emissions and Risk Reductions from California Locomotives and Railyards. Available:

http://www.arb.ca.gov/railyard/ted/083109tedr.pdf. Last accessed 30th May 2014.

Document extract: “In this report, the Air Resources Board (ARB/Board) staff provides a technical

evaluation for public comment of 37 options that may accelerate further state-wide locomotive and

localized locomotive and non-locomotive rail yard emission reductions. This technical evaluation of

each option addresses the technical feasibility, potential emission reductions, costs, and relative

cost-effectiveness. The purpose of this document is to provide a sound technical basis for the

ongoing dialogue on how best to achieve further emissions reductions of oxides of nitrogen (NOx)

and diesel particulate matter (PM or diesel PM).”

[4] Locomotive Technology Task Force. (2011). LOCOMOTIVE VEHICLE / TECHNOLOGY

OVERVIEW. Available: http://www.highspeed-rail.org/Documents/technology-vehicle_report-final-

2011aug11.pdf. Last accessed 30th May 2014.

Document summary: This document presents sixteen reports on various vehicles and technologies.

[5] RICARDO. (2012). GB Rail Powertrain Efficiency Improvements. Available:

http://www.ricardo.com/Documents/PRs%20pdf/PRs%202012/Q57475_DfT_GB_Rail_Diesel_Powert

rain_Efficiency_Improvements_Word_FINAL_14Mar12.pdf. Last accessed 30th May 2014.

Document extract: “This study identifies technology from non-rail sectors that could be applied to the

GB rail sector to improve the fuel efficiency of the diesel powered rolling stock. In addition, it

assesses successes and failures in applying new technology in the GB rail sector following

interviews with key GB rail industry stakeholders.”

[6] UIC, UNIFE. (2010). Innovative Integrated Energy Efficiency Solutions for Railway Rolling Stock,

Rail Infrastructure and Train Operation. Available: http://www.transport-

research.info/Upload/Documents/201203/20120320_094542_57698_Publishable%20Final%20Activit

y%20Report.pdf. Last accessed 30th May 2014.

Document summary: A list of different technologies are given from page 26 onward.

Powertrain innovation and energy efficiency (S195) Page 16

[7] US Department of Transportation. (2014). Best Practices and Strategies for Improving Rail

Energy Efficiency. Available: http://ntl.bts.gov/lib/51000/51000/51097/DOT-VNTSC-FRA-13-02.pdf.

Last accessed 30th May 2014.

Document extract: “The study identified rail industry and government Best Practices (BPs) and

strategies for improving the energy efficiency of freight and passenger railroads with technologically

advanced equipment and infrastructure, and/or use of alternative fuels, operations optimization tools,

and staff training.”

3.2 Electric Multiple Units (EMUs)

With regards to electrical motors, the Permanent Magnet Synchronous Motor (PMSM) represents a

promising motor technology, because of its very high energy efficiency of 97%. PMSMs utilise

permanent magnets in the rotor instead of the conventional excitation current to generate the

magnetic field, which minimises electric losses. Their lower cooling requirements enable PMSMs to

be mounted in totally enclosed configurations, which allows for lighter and more compact designs

with less maintenance and lower noise emissions. Additionally, the high torque offered by PMSMs

makes a gearless configuration easier to implement, which can further reduce energy losses and

weight. A major drawback of synchronous motors is the need for dedicated inverters, which raises

the investment cost. PMSM is a commercially available technology (e.g. Toshiba’s PMSM22).

Optimal management of the traction equipment according to the operating conditions may also lead

to increases in traction efficiency. For instance, shutting off some of the traction groups instead of

operating them all at partial load during coasting, cruising or standstill, may reduce energy losses in

motors and converters. These are operational measures that essentially require on-board traction

software optimisation, which means their implementation costs are relatively low.

List of selected papers

[1] Hitachi, Ltd. (2005). Inverter module for train traction systems. Available:

http://www.google.co.uk/patents/US6842352. US Patent: US 6842352 B2.

Document summary: This invention relates to an inverter module (module-type inverter device) to be

mounted on an electric railcar.

[2] Hitachi. (2010). Power Semiconductor Devices Creating Comfortable Low-carbon Society.

Available: http://www.hitachi.com/rev/pdf/2010/r2010_oct_101.pdf. Last accessed 30th May 2014.

Document extract: “Hitachi has been developing new power semiconductor devices, primarily

through collaboration and cooperation with power electronics departments in the fields of power

generation, rolling stock, automotive vehicles, industry, and consumer electronics. This report

estimates the market size of the power semiconductor devices in a low-carbon society with a “halving

of CO2 emissions.” It also describes Hitachi’s latest technology of power semiconductor devices and

the role of these devices in the future.”

[3] Indian Railways Institute of Electrical Engineering. (2010). Three phase technology in TRS

application. Available: http://www.irieen.indianrailways.gov.in/uploads/files/1302581203548-

Three%20phase%20Technology-291010.pdf. Last accessed 30th May 2014.

22 https://www.toshiba.com/tic/industrial/traction-motor/permanent-magnet-synchronous-motor

Powertrain innovation and energy efficiency (S195) Page 17

Document extract: “Three phase AC drive technology has become very common and significant for

modern rail vehicles. These vehicles are equipped with GTO thyristors and microprocessor control

systems. Microprocessor is used for vehicle control, supervision of health and operations of all major

components and diagnostics.”

[4] Kondo, M; Yasuhiro Shimzu; Junya Kawamura. (2008). Development of Totally Enclosed

Permanent Magnet Synchronous Motor. Available:

https://www.jstage.jst.go.jp/article/rtriqr/49/1/49_1_16/_pdf. Last accessed 30th May 2014.

Document extract: “The development of a 235 kW totally enclosed permanent magnet synchronous

motor for next-generation suburban trams presented m this paper. A novel cooling structure was

proposed, and its effectiveness was verified m a temperature rise test. An internal permanent magnet

structure optimized to increase reluctance torque was used to reduce the maximum current. The

results of testing and calculation show that this new motor can reduce the energy consumption of the

tram by 12% and acoustic noise emission by 7 dB.”

[5] Rivera. N, PE SPAD Engineering Company. (2007). Permanent Magnet DC Traction Motor with

Reconfigurable Winding Control. Available:

http://onlinepubs.trb.org/onlinepubs/archive/studies/idea/finalreports/highspeedrail/hsr-

44final_report.pdf. Last accessed 30th May 2014.

Document extract: “This project is to design, build and test a prototype locomotive traction motor

based on a new electric machine technology defined as a “permanent magnet direct current machine

with reconfigurable winding control”. The most significant innovations in this technology are the

topologies of magnetic circuits and windings and the solid state switching and control system that

replaces either the commutator and brushes or an external power converter.”

[6] Siemens AG. (2008). Energy efficient solutions for the complete railway system. Available:

http://www.uic.org/cdrom/2008/11_wcrr2008/pdf/PS.2.32.pdf. Last accessed 30th May 2014.

Document extract: “Innovative technologies for the power supply of electric railway vehicles by

stationary and mobile devices allow to operate the complete railway system in an energy efficient

manner and therefore reduce the energy consumption considerably. So it is necessary to optimize

the power supply of the railway network as well as the railway vehicles and their own operational

behaviour within the railway network. A complete tramway system was chosen as an example.”

[7] Soulard. J of KTH, Bombardier Transportation. (2012). System Analysis of Permanent Magnet

Traction Drives. Available: http://www.gronataget.se/upload/PublikaDokument/TR22_2012.pdf. Last

accessed 30th May 2014.

Document extract: “The technology of traction electrical motors for train application has evolved from

DC motors to AC drives with both synchronous and induction motors in the last decades. Three-

phase permanent-magnet (PM) synchronous motors are both smaller and lighter than induction

motors (IM) for a given torque with same cooling conditions. However, this also implies new system

challenges to be solved. Besides supporting the activities involving design, prototyping and testing of

the PM motors in laboratory and vehicle environment, a number of theoretical investigations have

been conducted by KTH researchers. Thermal modelling and loss calculation tools were developed.

The main effort was dedicated to the investigation of winding failure and its possible consequences

Powertrain innovation and energy efficiency (S195) Page 18

from original short-circuit to worst possible conditions of the PM motor after failure propagation

without mitigation strategies.”

3.3 Vehicle weight reduction

Lighter vehicles present lower mechanical resistance to advance and require less kinetic energy to

reach the same level of performance; therefore, minimising the overall mass of rail vehicles reduces

their traction energy consumption. Furthermore, reducing the weight of rolling stock results in less

damage to the track and reduced wear of wheels and brakes, consequently lowering the operational

and maintenance costs of the system.

A straightforward method to reduce the vehicle’s weight is to introduce lightweight materials such as

composites. Mass reduction measures should be primarily implemented at design stages, although

retrofitting may also be a viable option. In addition to the use of lightweight materials, the overall

mass of rail vehicles can be reduced by upgrading the traction equipment (e.g. Hitachi’s has

introduced lighter EMU inverters23).

For example, the use of Permanent Magnet Synchronous Motors (PMSM), gearless drives and

power converters based on new semiconductors, may result in significant mass reductions.

There are two main types of mass reduction: component-based lightweight design, which focuses on

reducing the weight of specific components without fundamental changes to train configuration, and

system-based lightweight design, which redesigns the whole train system optimising for weight.

Component-based lightweight design looks to make use of lightweight materials such as aluminium

in place of conventional types of steel, and the industry is starting to introduce aerospace material to

rail24. An example of component-based lightweight design is ABB’s new lightweight power traction

transformers25. In contrast, system-based lightweight design includes reducing the number of bogies

and replacing 2-axle bogies with single-axle running gear, as bogies make up a third of the weight of

a train.

List of selected papers

[1] Central Japan Railway Company. (2008). Innovative lightweight traction system technologies

employing power electronics on the Shinkansen high-speed EMUs. Available:

http://www.uic.org/cdrom/2008/11_wcrr2008/pdf/PS.1.27.pdf. Last accessed 30th May 2014.

Document extract: “This paper starts out by introducing environmentally friendliness of the

Shinkansen in terms of low energy consumption by means of traction system change of innovative

Shinkansen trains, and then continues on by introducing recent technological innovations that have

given birth to lightweight traction systems, such as the Permanent Magnet Synchronous traction

Motor (PMSM) and power converters with train-draft-cooling systems. The paper concludes by

introducing environmentally-friendly aspects of the Tokaido Shinkansen.”

[2] Hitachi. (2010). Technology for Next-generation Reduced-size High-performance Inverter.

Available: http://www.hitachi.com/rev/pdf/2010/r2010_01_103.pdf. Last accessed 30th May 2014.

23 http://www.railwaygazette.com/news/single-view/view/hitachi-introduces-smaller-emu-inverter.html 24 http://www.atkinsglobal.com/projects/introducing-aerospace-material-to-rail 25 http://www.railway-technology.com/news/newsabb-develops-new-power-traction-transformer-to-increase-

trains-efficiency/

Powertrain innovation and energy efficiency (S195) Page 19

Document extract: “Hitachi has developed a new generation of reduced-size high-performance

inverters. The key concepts behind this development are compatibility with next-generation

technologies and improved environmental performance.”

[3] NewRail Newcastle University. (2012). Transport of DE-LIGHT: the design and prototyping of a

lightweight crashworthy rail vehicle driver’s cab. Available:

http://www.ncl.ac.uk/newrail/assets/docs/Robinsonetal-TransportofDE-LIGHT.pdf. Last accessed

30th May 2014.

Document extract: “This paper describes the design, validation and prototyping of a lightweight

crashworthy rail vehicle driver’s cab using advanced composite sandwich materials. By exploiting the

light-weighting, energy absorption and design integration benefits of composites, an innovative

modular cab structure was developed that provides significant savings in mass, cost and part count

compared to conventional cab designs.”