High speed train – Rolling stock
Note: For educational purpose only. This page is meant purely as a documentation tool and has no legal effect. It is not a substitute for the official page of the operating company, manufacturer or official institutions. It cannot be used for staff training, which is the responsibility of approved institutions and companies.
👉 (Version française pas encore disponible)
Site map High Speed Railways
1 – Overview → 2 – Infrastructure → 3 – Rolling Stock → 4 – Train services → 5 – Economics & Post evaluation
Key words
This section explain:
• Main technical specifications
• Speed
Main Technical Specifications
The primary characteristic of high-speed trains is that they are, in all cases, self-propelled trainsets rather than locomotive-hauled consists as in conventional trains. High-speed operation requires sustained attention to key aspects such as wheel–rail adhesion, running resistance (aerodynamics), pressure waves and air blast effects in tunnels, ballast flight, and sensitivity to crosswinds. Also critical is the vertical wheel–rail contact, which is subject to significant mechanical and vibratory loads, as well as high-speed acoustics, current collection, and the bogie’s dynamic stability and critical speed.
The articulated trainset is the original concept introduced by the Japanese as early as the 1960s. It was later adopted by the French in the 1970s, and subsequently by high-speed rail operators across Europe and worldwide. The configuration of this type of trainset provides better track stability and eliminates the risk of losing a carriage, as can happen with a conventional train.
These trainsets are by definition bidirectional, as they do not feature a separate locomotive. This also allows for quick turnaround operations at terminal stations. The drawback, according to critics, is that these trainsets cannot be easily adapted to seasonal variations in passenger demand due to their fixed composition. Furthermore, a failure in a single unit results in the immobilization of the entire trainset, which must then be sent to the maintenance depot—potentially representing an economic loss.
High-speed trains are therefore fixed trainsets, but not all share the same technical characteristics. Two main features distinguish them:
- Distributed traction along the entire trainset, or end-mounted traction provided by one or two dedicated power car;
- Trainset architecture: articulated, meaning that each car is connected to the next via shared bogies, or conventional, with cars equipped with two bogies each and coupled together in a fixed formation.
The table below summarizes these characteristics for the most commonly used rolling stock currently in service:
[TOP]
Speed
The choice of the design speed for a high-speed rail system is driven far more by economic considerations than by technical limitations, since the potential maximum speed of high-speed rail is significantly higher than the speeds envisioned for commercial operation.
The economic optimum speed is a parameter that evolves over time, taking into account both technological advancements and changes in the perceived value of time for passengers. The current global consensus among most countries engaged in high-speed rail lies within the range of 300 to 350 km/h.
Given that no conventional train exceeds 220–230 km/h, a number of specific regulatory requirements for high-speed operation have been established in Europe under the so-called “LOC & PAS” Technical Specifications for Interoperability (TSI). These requirements are regulatory in nature because they are inherently linked to the technical constraints of high-speed operation.
In addition, the maximum allowable speed for high-speed trains is also determined by the physical limits of the traction equipment, the power system, and tolerable aerodynamic effects (airflow, pressure wave discomfort, etc.). Various records and test campaigns conducted in the 2000s demonstrated that above 400 km/h, excessive heating occurs in the traction chains, track geometry issues emerge, and energy consumption in the catenary increases sharply. All of these factors called into question the economic viability of ultra-high-speed operation.
All current high-speed trains are theoretically designed for an operating speed of 350–360 km/h, maybe more. Under normal operating conditions, and depending on the incidence of delays and the characteristics of the terrain, HSR services are usually provided at average operating speeds of 20-30 km per hour below their maximum operating speed, which is the optimal technical speed in relation to which the useful life of the rolling stock is calculated and the recommended maintenance plans are designed by the manufacturers.
Speed is also determined by the type of service to be provided. In a hub-and-spoke service model, as in France or Spain, long non-stop journeys support operating at maximum potential with speeds of 300 km/h. This is not the case in Germany, Italy, Taiwan, or even Japan, where intermediate stops require operating at lower speeds while still delivering a high level of service to passengers.
Today, commercial operation reaches 320 km/h on the Paris–Strasbourg high-speed line. On other lines, day-to-day operating speeds generally range from 280 to 300 km/h depending on conditions. 🟧
[TOP]
——————————————————————————————————————————————————————————————-