Transport

Note dd July 7, 2023: The article below is a legacy article developed in 2017-2018. It may no longer be up to date in this fast-evolving field.

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Today, copper plays a critical role in transport for functionality, efficiency, comfort and safety and has been a key component in vehicles since the dawn of the car industry.

Copper is a multi-purpose material whose properties have made it a key component in vehicles since the dawn of the car industry with the Model T Ford in 1916. Today, copper plays a critical role in cars for functionality, efficiency, comfort and safety. Even the most basic model contains some 1 km of wiring, mostly used to carry data, send control signals and supply electrical power. The total weight of copper in a vehicle ranges from 15 kilos for a small car to 28 kilos for a luxury car.

Where copper can be found in a typical passenger car

Electrical Distribution Systems

Motors, alternators, actuators and electrical chokes, and the wiring harness itself, all depend on reliable high conductivity. More copper will be needed as automotive electrical developments increase awareness, safety and automation. Electrified railways, trams and light railways are powered through overhead copper alloy contact wires. High quality brass has the long-life springiness and resistance to corrosion that makes it ideal for electrical connections.

Electronics

Car designers and manufacturers are constantly developing electronic applications which rely on the electrical conductivity of copper:

Sensors (Pressure, Temperature, Speed)

Sensors for the automotive industry make up around a third of the global sensor market. With a true sensory system for the car, the sensors allow, for example, dangers on the road to be detected, braking to be adapted, the temperature inside to be controlled, self-diagnosis tests to be run on the vehicle. They make use of copper – notably, in the coils and cables.

ABS or Antilock Braking System

This was one of the first ‘smart’ technologies, designed to make driving safer by adjusting the braking depending on the grip. Since then, a whole series of innovations have expanded the solutions available with regard to braking and road grip, including EBD (Electronic Brake-force Distribution) for improved distribution of the brake force or ESC (Electronic Stability Control) that enhances the stability of the car.

Driving Controls

More than a mere speed regulator, the AICC (Autonomous Intelligent Cruise Control) allows a speed previously set by the driver to be maintained without having to keep the foot on the accelerator. A technology available on top of automatic transmission, the AICC monitors the speed of the vehicle in front and changes its own speed accordingly, while keeping a good safety distance.

The car is now much more than a pure means of transportation. It is designed to be comfortable and equipped with work and leisure spaces. Thanks to an ever increasing number of applications that exploit copper’s benefits, the seats are able to remember and automatically adjust to the passenger, thanks to an array of small motors. Automatic temperature controls keep the interior at a comfortable level and telecommunications are accessible from even the most modest cockpits (hands-free mobile phones, navigation assistance, security trackers, DVD players and even internet connectivity). Copper has opened up a new window onto the world.

In the future, it is likely we will have an autopilot system driven by accelerometers, combined with actuators that will control driving, speed and braking. 360° radar and cameras will keep a constant eye on traffic and the vehicle’s position. Connecting the myriad of connectors, sensors, mini-computers and advanced telecommunications systems, nestling under the bonnet of our smart cars, it will be copper wires that will carry the key power and data signals that will deliver all the above benefits.

Reducing Emissions

Copper has an important role to play in systems designed to reduce petrol consumption and CO₂ emissions. Direct injection systems allow a more precise control of the air to petrol ratio, thereby cutting fuel consumption and exhaust emissions. Traditional camshafts are also slowly being replaced with electronic valves that further improve engine efficiency. Copper has a role to play in hybrid and fuel cell vehicles and researchers are actively looking at new propulsion systems. Firstly, hybrids which combine conventional combustion engines with electric motors can provide an interim solution. Conventional fuels are used for long journeys and the electric motor for the urban environment. Secondly, work is being done to develop fuel cell driven engines, a solution that creates almost no pollution. These two different systems, both with their powerful electric motors, can contain up to 12 kg of copper.

Heat Exchangers

A new heat exchanger has been developed using CuproBraze® technology, a cost-effective, environmentally friendly process, low in investment cost. It produces strong, reliable brazed copper/brass radiators with performance and cost advantages over aluminum radiators. Given its high pressure resistance, plus its ability to resist both high and low temperatures, this technology is becoming increasingly chosen in market segments that demand absolute reliability in extreme conditions: long distance trucks, farm and construction equipment, generators and all terrain vehicles. When the usable lifetime of the radiators has expired, the copper in the radiators can be recycled to produce new radiators or other copper products.

Cuprobraze radiators for automotive, off-road and military applications

Brake Lines

The braking system in vehicles is a vital safety critical item. Brake systems depend on the transmission of either pneumatic or hydraulic pressure and brake tubing may be in a particularly vulnerable exposed position which requires good resistance to corrosion by salt, fatigue strength and impact resistance.

Volvo began the use of 90-10 copper-nickel tube in their 1976 model vehicles and are still using it as are Audi, Porsche and Aston Martin.

Copper-nickel automotive brake lines

Trains, both surface and underground where the pneumatic brake pipes are subject to very severe working conditions often use a brass tube alloy Tungum for their primary brake lines.

Air and Oxygen Gas Lines

Copper and copper alloys are non sparking and can transmit air/oxygen safely. An example of this is shown in the Black Magic trainer aircraft where the brass alloy Tungum carries air oxygen to the pilot.

Gearbox

In contact with moving parts in the engine, copper alloys provide a surface which does not stick or wear easily whilst being strong enough to provide support. In this application it acts as a bearing. Copper alloy bearing materials are used for selector forks and heavy duty bearings.

Electric Vehicles

Electric vehicles and hybrid vehicles, which supplement a conventional motor with an electric motor, have reached a new stage of development. Leading car makers have already invested considerable work and financial resources in such systems. Since an electric motor is used in both vehicle types, they contain considerably more copper than conventional cars.

The UK Government has set targets for the take-up of low emission vehicles:

• for at least 50% — and as many as 70% — of new car sales to be ultra low emission by 2030, alongside up to 40% of new vans.
• the UK will end the sale of new conventional petrol and diesel cars and vans by 2040.

For more information go to The Office for Low Emission Vehicles (OLEV).

Trains

Modern rail vehicles are extremely copper-intensive. High-speed trains, for example, use ten tonnes of copper per kilometer of track. The most powerful electric locomotives contain more than eight tonnes of copper, while in a commercial aircraft, this metal accounts for only about two percent of the weight, but corresponding to more than 190 kilometers of copper pipe. The use of adequate conductor cross sections saves energy in rail transport and increases the reliability of existing rail infrastructures.

Electric trains rely on copper contact wires

How Much Copper is Needed?

The vision of a lower carbon transportation system, delivered by affordable, hybrid and electric vehicles, connected to smart grids, along with high-speed rail networks, requires copper.

Low carbon electricity sources, such as renewables, and the distributed electricity systems required to incorporate and manage them, need four to ten times the copper content of electricity produced via centralised, fossil fuel generation.

Copper Use in Electric Vehicles

Each type of EV uses considerably more copper than traditional vehicles with internal combustion engines. Copper usage for each vehicle type is listed below:

• internal combustion engine: 23 kg of copper.
• Hybrid electric vehicle (HEV): 40 kg of copper.
• Plug-in hybrid electric vehicle (PHEV): 60 kg of copper.
• Battery electric vehicle (BEV): 83 kg of copper.
• Hybrid electric bus (Ebus HEV): 89 kg of copper.
• Battery-powered electric bus (Ebus BEV): 224–369 kg of copper (depending on the size of the battery).

Copper use in cars for different technologies

Copper Use in High Speed Trains

Each high-speed train requires 10 tonnes of copper components, plus 10 tonnes in the power and communication cables per kilometre of track.

Ever Wondered How a Lithium-ion Battery Works?

Cu foil is the common anode current collector in commercial lithium ion batteries and accounts for approximately 10% of the total cell weight.

FAQs

Q1 What copper/copper alloy may be used for vehicle radiators?

When good heat transfer is essential, as in vehicle radiators, copper and brass are excellent choices due to their high thermal conductivity and ease of brazing, especially in thin sheets.

Q2 What type of copper is specified to make wire used to transmit electricity to trams, trolley buses or trains?

Pure copper is too soft for overhead wires and the copper alloys used are specified in BS EN 50149:2012. These are alloys of copper with respectively small amounts of silver, magnesium, tin or cadmium.

Q3 When a car is scrapped, can the copper be recovered?

Yes, copper is easily separated from other materials such as steel and plastic. It is recovered, remelted and reused.

Q4 Where is copper used in cars and trucks?

A high-purity copper wire harness system carries current from the battery throughout a vehicle to equipment such as lights, central locking, onboard computers and satellite navigation systems. Electric motors, which are wound with high conductivity wire, are also used in many vehicles. The average car contains about 1 km of wire.

Q5 Which grade of copper is used for vehicle brake pipes?

Copper and copper-nickel tubes are used for vehicle brake pipes due to their good fatigue and corrosion resistance (especially against salt on the roads), where fluid loss could be disastrous. Because of their ductility, they are easy to fit; they are standard equipment for many cars, fire engines, military vehicles, JCBs and other heavy vehicles.

Q6 Which type of brasses are specified for terminal posts used in signalling and ancillary equipment in the London Underground?

The following brasses have sufficient strength, machinability and electrical conductivity: CW508L (CZ108), CW509L (CZ109) and CW614N (CZ121).