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             | 4rail.net
- Railroad Inventions and Innovations Welcome to the new page which is gradually forming! We will add a lot of material here in the near future. |  Created for 4rail.net by John McKey and Charles Phillips. Pictures by Ilkka Siissalo, Sanna Siissalo, Charles Phillips, Siemens AG and John McKey.  | |
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| Articulation * Impact Reducer Seats * | |||
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 | Articulation Articulation in use usually means two coaches sharing a bogie on a multiple unit. Articulation is used for saving space and to reduce the weight compared with the coaches with individual bogies. In case of the TGV it also provides with other structures support for keeping the train aligned and avoid deadly zigzagging commonly associated with train accidents. The accidents with TGV have proven articulated structures worth: excellent protection for the passengers. Because of the articulation and other structural choises the TGV's have proven to be the safest high speed trains in use.  More on articulation...
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| Jacobs Bogie | |||
| Energy
Feedback to Electric Networks | |||
   | Safe
Seats for Impact Reducing on the High Speed
Trains
Recently crumple zones, long used in cars, have been introduced in passenger coaches so as to absorb the energy more gradually in the event of a front-end collision with the intention of reducing the harm done to passengers. However, this measure can only introduce an improvement of limited degree and passengers still travel forward at the original traveling speed while the coach comes to what is still a sufficiently abrupt halt to cause injuries. Passengers are therefore thrown forward with resulting serious injuries in most cases and even death. Seat belts are not provided in the case of trains apparently because the custom became established of seeing trains as more relaxed environments in which people can move about freely. Although the primary focus is to the saving of lives and injury to persons, the invention can have benefits in the transport of articles, especially for example fragile articles that require protection from large G forces in certain directions. The design of the impact reducer is thus in its first aspect to change the attitude of the seat in which it is normally horizontal or close to horizontal to an attitude in which it is tilted backwards so as to shift the trajectory of the inertial force which acts through the center of gravity of the person and seat to be directed through the seat rather than the backrest. This is crucial to ensure that the person remains within the seat when it decelerates upon an impact occurring to activate the second phase or at least so as to reduce the tendency for a person to slide off the seat when it decelerates upon an impact occurring and instead to tend to settle the person more securely in the seat. The back rest is not the focus of the invention, however, if restraining means, for example seat belts, including the three point seat belts, these should be secured to the seat, if significant forward movement is provided for upon impact. The second key aspect of the invention, the energy absorber, is designed to absorb energy as the seat moves forward, so as to bring the seat to a halt progressively over the distance that the seat moves forward upon an impact occurring. This reduces the forces acting on the body of the person as compared to a sudden or near instantaneous stop where the forces can become enormously great, so as to avoid serious injury or death. The energy to be absorbed will vary according to the combined mass of the seat and the passenger, the latter obviously varying according to the passenger. The energy to be absorbed will also vary according to the speed of the vehicle concerned at the moment of impact. The rate of energy absorption with displacement of the seat must be proportional to the product of the speed and the total mass of seat and passenger, that is, the momentum of seat and passenger. Since the mass of the seat is a constant the range of masses resulting from persons of different mass that must be catered for is reduced. The product of speed and mass is the momentum of the seat and passenger and this must be absorbed by the energy absorber by the work done over the distance that the seat moves after impact, being the product or integral of the resistance over this distance. Energy absorption can typically be provided by dry frictional effects or viscosity effects, the latter for example in hydraulic dampers or ?shock absorbers? as used in suspension systems, duly modified for this purpose or purpose designed viscous dampers. Both frictional, pneumatic and viscous effects can be applied in the mechanism. The range of possibilities that must be catered for is wide, for example a child that weighs 25kg may have to be brought to a halt from 40 km per hour or a man that weighs 135 kg may have to be brought to a halt from 360 km per hour and every scenario in between. To cater for this the energy absorber must preferably be adjustable and this can be achieved through various known devices. The adjustment must be automatic by weighing the combined weight of the seat and person sitting on it and by measuring the speed at any given instant. Trains, coaches and buses seem to be the most apt applications for the invention, but in principle it may be adapted to other vehicles, such as aircraft and passenger cars, allowing for suitable adaptation to the more limited space for forward movement and tilting action. | ||
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