For public transport to be acceptable to the travelling public, it has to meet two major requirements: firstly it has to be fit for purpose and, secondly, it has to be pleasant to use.

So design of carriages has to meet both the objective criteria for an efficient and functional mechanical and electrical design; and the subjective criteria for a comfortable and welcoming appearance.
One well-established company that has successfully combined these two challengesfor many years is Creactive Design, anaward-winning expert design and engineering consultancy to the rail industry, based in the UK. Its teams design and engineer all aspects of railway vehicles, carriage interiors and exteriors, for rail operators and manufacturers, including light rail, heavy rail, rolling stock, interiors, branding, ergonomics, manufacturing and engineering. This has resulted in long-term relationships with many global companies.
Neil Bates, a partner in the company, says the team has to understand fully all the ramifications of a proposed design. But designs can be overworked, he says. "The moment a design starts to become overpowering, it can make people feel uncomfortable. Getting the details right is about knowing when to stop."
These principles apply to carriage design and Bates says potential rail customers have to be convinced that the train is a desirable travel alternative. So appealing design has a large part to play in helping achieve this.
Chiltern Railways briefed Creactive to develop a high quality design solution to attract regular car commuters who use the M40 motorway which runs parallel to the line. The result was one class of travel throughout, a combination of 2x2 and 3x2 seating layouts, improved facilities for standing passengers, new information systems, air cooling, designated wheelchair areas and improved materials and finishes that created a new class 165.
Focus groups were used to measure the feedback Chiltern regularly receives from its Rail User Groups and now the train is used by 11 000 daily commuters on trips under an hour, for whom safety, punctuality and availability of seats are top priorities. Customer surveys show Chiltern Railways are now the second most highly thought of rail franchise second Eurostar.

The company places a very strong emphasis on understanding customers' preferences for all its designs. It uses research and focus groups for feedback to ensure that designs meet users' needs. It then makes extensive use of computer simulations and mock up models so people can easily appreciate what the result will look like. This has brought work in from Africa, the Far East and Europe.
One example is the Metrolyte Seat, developed as a replacement seat for London Underground's Central Line trains. It addressed many of the problems that were encountered with the original seat and was designed to meet more stringent fire test requirements.
Creactive developed a comfortable, long life upholstery system with good fire test performance for smoke emission and fume toxicity. This is supported on a lightweight frame based on formed extrusions and the seat weighs less than half that of the original, has only one configuration of replaceable upholstery instead of five and is much easier to service and maintain.
The company also appreciates that delivering short design times is important to clients. A typical case was designing new chiller cabinets for the refurbishment of the Bombardier GNER Mark IV rolling stock. Lead times were very tight and the design programme was completed in four weeks from being briefed. It included the creation of 81 unique parts, 17 sub-assemblies and 65 associated production drawings.
Once a visual design has been created, choice of specific materials is a critical factor. Low weight is essential to reduce energy consumption but the material has to be sufficiently strong to meet crashworthiness standards and to maintain dimensional stability.
Today, this means extensive use of composites and led aircraft manufacturer Slingsby Aviation to diversify into rail transport in order to utilise fully its wealth of knowledge of composite technology.

It first designed and developed emergency detrainment doors with built-in steps to enable access to the ground or to another train, in the event of an incident. This led to further tailored solutions for individual customers and end users.
Slingsby Aviation also manufactures drivers' consoles using new processes it has developed. These enable train front ends to be moulded to provide stronger and lighter structures, offering more crash protection at lower cost.
The company says that a major advantage of composite materials is the wide choice of both resins and reinforcing cloths, which provides the designers with an extensive set of material combinations that have distinct and differing mechanical properties. This enables composite materials to be used for a broad range of applications.
Reinforcements provide composite structures with their strength and stiffness, their insulating qualities and radio and radar transparency associated with glass reinforcement.
Material selection is probably the most important aspect of any composite design and is dependent upon a number of factors, especially the operating and environmental conditions of the product and cost. So Slingsby has developed a comprehensive Materials Database to assist its design engineers.

Increased performance

Compotech AG in Weinfelden, Switzerland, also develops and produces technical components and systems made of reinforced plastics. It says the performance of modern industrial products is increasing all the time as regards stability, shaping and weight etc.
Fibre composite technology can meet these demands. The use of various fibre types, combined with various resin systems and additives, allows us to produce components which can meet virtually any set of requirements. This allows conventional materials such as steel, aluminium or wood to be replaced by plastics efficiently.
The company uses handlay techniques for large and complex products, for one-off items, prototypes and small series. It uses moulds which are open at one side to produce the workpiece. Resin is applied or sprayed on and reinforcing fibres are incorporated alternately on a fine layer. But it adds that handlay requires great craftsmanship and experience.
The SMC hot-moulding press process is also used frequently for large products. Besides thermosetting compounds such as polyesters, it is also possible to use the process with thermoplastic prepregs such as glass mat-reinforced thermoplastics. The prefabricated mats are cut to size at the press and placed in the preheated steel tooling. After the press closes, the moulding hardens. The pressed product is smooth on both sides and can be produced within a very short cycle time. Components can be produced with dimensions up to2.5 x 3m.
Vapor Rail Inc is Wabtec's Centre of Excellence for the design and manufacturing of door systems for passenger rail vehicles. It says the increasing volume of passengers requires innovative and timesaving solutions that insure greater efficiency in transport management.
To meet this demand, Vapor Rail designed the Intelligent Door System (IDS): a unique responsive door control concept that offers great programming flexibility and safety.
The IDS motion control processor can differentiate between obstructions in doors from normal frictional factors and respond immediately. Its unique two-stage lock permits a train to leave a station with the doors locked in an active electronic pushback mode.

Safety move

To further improve safety in carriages, a new range of UK common Passenger Safety Signs has been designed and developed by international rail business consultancy Interfleet Technology and their human factors specialists Davis Associates.
These new signs and accompanying design guidelines were commissioned by the Rail Safety and Standards Board (RSSB) research programme and the Association of Train Operating Companies (ATOC).
Around 100 new signs have been developed, incorporating scientifically designed symbols, and will become the standard for use in all UK rail vehicles. The new signs include instructions for the use of fire extinguishers, emergency exits, door release mechanisms, passenger communication alarms and emergency window hammers and should assist both passengers and train crews in dealing with emergency situations.
The major consideration was to reduce the necessity for reading text through the use of common symbols that would convey their precise meaning with little or no text. The symbols were designed for maximum clarity when printed on glow-in-the-dark material.

Besides the visual impact of good carriage design, there are other aspects that contribute to a good passenger experience and that includes reducing noise and vibration.
Freudenberg Schwab GmbH is one company that develops and supplies complete anti-vibration and suspension systems and components for railway vehicles, both passive and active. It says that a key consideration is to maximise the life of components to reduce maintenance costs.
Its active vibration absorbers have revealed completely new options and degrees of freedom for vibration control engineering. In the case of interior noise with high periodic content for example, the benefit obtained from active absorbers is very high, reaching noise reduction up to 10 db(A).
Initial trials have also shown that active vibration absorbers can significantly reduce the structure-borne noise transmitted into the interior as a result of wheel out-of-roundness.
Schrey and Veit is also working on new fields of vibration technology using tuned dampers and vibration isolators. It says the task of the new wheel absorber generation consists of the broad-band reduction of structure-born noise using a very simple and compact method of construction. This is achieved by the conduction of vibration energy and conversion into dissipation energy with specially developed damping materials.