Page 337 - 360.revista de Alta Velocidad - Nº 5

Influence of Aerodynamics in Tunnels Design

However, ADIF (Spanish Railway Administrator) includes in the standard NAP 2-3-1.0 (2015), in
section 3.2 “Comfort criteria” the following summarized in the next table:

Pressure Difference
TRAIN TUNNEL t(s)
(kPa)
Single track 2 4
Non sealed trains
Double track 4 4
1 1

Single and Double 1.6 3
Sealed trains (τ = 6s)
tracks 2 10
3kPa during all the time the train is in tunnel

Table 2 Comfort criteria included in NAP 2-3-1.0 (ADIF)

NAP 2-3-1.0 (2015) also indicates that the UIC Leaflet 779-11 (2005) Code cannot be used for
sizing, just for pre-sizing of the cross-section. However, during the first years of development of
the high speed in Spain, the UIC Leaflet and the Recommendations from the Ministry of Works
were also used.

3. First steps

25 years ago or maybe before, aerodynamic issue was a totally unknown phenomenon in Spain.
The main reason was that this issue had never been considered because high speed lines were
not a reality in Spain.

The way in which as designers considered this aspect was the following. First of all, the UIC
Leaflet was considered for both constraints, health and comfort.

These first steps, which are described below, do not have to be the same as those in other
countries, since the evolution in this area has been very fast. On the other hand, the dimensioning
that is described is due to aerodynamic effects without taking into account the geometrical
condition, always existing, and which was always taken into account as will be seen below.

During the firsts years of evolution in the design of tunnels of High Speed Lines, the tools that
later would be available, have not been developed yet. This was the main reason why initially
the calculations, or rather estimations, were made in Spain by means of the leaflets provided
by UIC Code 779-11 (2005).
These leaflets were first developed in 1995, followed by the European Rail Research Institute
(ERRI) Specialist Committee C218 that in 2005, through the use of the SEALTUN and AIRSHAFT
programs, these international leaflets were created for users. The main idea of these
leaflets was to facilitate the sizing of the high-speed tunnel cross-section. Note that all the
recommendations, criteria and considerations that included these leaflets were the same ones
that were included in the 2008 TSI’s.

The calculation factors that the leaflets from UIC Code considered for sizing cross-sections are
the following:

International Congress on High-speed Rail: Technologies and Long Term Impacts - Ciudad Real (Spain) - 25th anniversary Madrid-Sevilla corridor 335