Lightweight Garage #5 CFRP Lightweight Train CETROVO from CG Rail GmbH

July 22, 2021 from Julius Winkler

©Bernulius/stock.adobe.com

The Vehicle

The use of carbon fibre reinforced plastics (CFRP) has been state of the art for aerospace applications for several years. In the automotive industry, there are vehicles in which CFRP is used, too. The comparatively expensive material was previously not found in rail vehicles. However, the increasing desire for energy efficiency is also leading to a rethinking in this industry. After all, every tonne of weight saved on the vehicle not only reduces the axle loads and wear and tear on the railways. It also leads to energy savings of 0.7-22kWh per 100km.

With this in mind, CG Rail GmbH has developed a metro train as part of the CETROVO project, which consists almost entirely of CFRP components. A prototype has already been manufactured and exhibited for the first time at the InnoTrans traffic fair in 2018.

©Markenbüro, CC BY-SA 4.0, Prototype of the CETREVO CFRP-metro train

The Technology

The most important innovations of the train are the bogie frame, the car body, the front cab and the underfloor cladding, which are all made of CFRP. Several new technologies are used here.

The bogie frames in a CFRP differential design consist of two longitudinal and two cross members. Automated preforming using braiding and winding is used as a production technology. The result is a bogie frame that is 50% lighter and whose service life of over 33 years has been proven by cyclical tests.

©Markenbüro, CC BY-SA 4.0, CFK Drehgestellrahmen des CETREVO

A CFRP share of 70% also leads to an ultra-light car body design. It is 30% lighter than a comparable aluminium construction. This can be achieved by further developments in the pultrusion process. As a result, large CFRP multi-chamber profiles with wall thicknesses of up to 25mm and different fibre types and fibre orientations can be manufactured in one piece. There are almost no limits to the length of the profile.

©Markenbüro, CC BY-SA 4.0, CFRP Car Body of CETREVO

The Lightweighting Effect

For the entire train, there is a weight saving of 13% compared to a conventional metallic construction. Overall, this makes the metro train 15% more energy efficient.