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Tunnelling the Gotthard - the success story of the Gotthard Base Tunnel

  • Heinz Ehrbar Partners LLC

Abstract and Figures

Tunnel construction – it really is more than just digging a hole in a mountain. Tunnellers interlink regions, bring people together and contribute to the future of countries and whole societies. It’s true all around the globe, and it’s especially true of the Gotthard. The Gotthard Base Tunnel is a symbol of Swiss precision, reliability and innovative inspiration and is in addition the world’s longest railway tunnel. (Doris Leuthard)
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Heinz Ehrbar
Luzi R. Gruber
Peter Zbinden
“No construction project is risk free” a long-proven dictum
tells us. It is also true, in particular, of large-scale projects and
even more so for major underground-engineering projects.
Courage, endurance and far-sightedness are the essential
preconditions for the achievement of such projects and for
overcoming the hazards. Is this statement a mere platitude?
Most decidedly not, as a glance at the history of the Channel
Tunnel, for instance, will illustrate: the basic idea has been
taken up no less than six times since 1802. Tunnelling was
actually started in 1880, 1922 and 1974, only to be aban-
doned again after a few hundred metres or, at maximum,
1.8km (in 1880).
There was certainly no lack of courage on the part of the con-
structors, but the preconditions for completing the project
with endurance and far-sightedness were not right in the three
unsuccessful attempts. After the fourth attempt and a con-
struction and commissioning phase of around seven years, the
tunnel, a technical tour de force, was then actually opened
to traffic in 1994. Difficult financial and commercial boundary
conditions even today continue to force the enormous tech-
nical achievement into the background.
Does a similar fate await the Gotthard Base Tunnel (GBT)? We
know no one can foresee the future– least of all when import ant
technological revolutions are on the horizon, such as the now
frequently discussed automated control of road vehicles. Despite
these challenges, there are still numerous factors which could
make the GBT project an overall success even in the longer term:
1. There is a clearly defined need, on the basis of freight
traffic alone, for the project, which is the core element
inEuropean Rail Corridor A (Rotterdam–Genoa).
2. The GBT makes European Corridor the first low gradient
north-south rail route through the Alps.
3. The funding model chosen at the beginning of the
project relieves the operator of obligations to repay the
initial investment and is intended to enable it to operate
4. Efforts to achieve interoperability (i.e. rail operation under
a common European standard for control and safety
systems) are now well advanced and will also further
enhance the rail infrastructure in general in the future.
Figs 1 and 2 The first attempt at constructing the Channel Tunnel, 1880
Credit: (14 January 2016)
There had been talk of a Gotthard base tunnel since 1947,
an idea which, like that of the Channel Tunnel, was taken
up again in the 1960s, 1970s and 1980s. The Swiss Federal
Railways (SBB) submitted its construction project for a GBT
to the federal government in 1975, but this was not imple-
mented in view of the stormy political and economic situ-
ation. A book summarising this story bears the subtitle of
“Victim of politics and faint-heartedness”. We shall not
judge here whether this is true or not. One thing, however,
is certain: the 1975 construction project provided an excel-
lent basis for all subsequent deliberations and was, on this
criterion, money well spent.
On 23 May 1990, on the basis of the deliberations for the
1975 project, the dispatch on the construction of the Swiss
rail link through the Alps was submitted, and a federal decree
adopted by the Swiss Parliament concerning the overall appro-
priation for implementation on 1 October 1991. A comparison
of these documents with our present-day knowledge shows
that the dispatch was drafted comprehensively and politically
wise. The benefits of the project in the European, Swiss and
regional context were rationally derived, analysed and stated.
Opportunities and threats were recognised and evaluated dur-
ing the earliest project phases, and corresponding provisions
for each phase outlined.
The above-mentioned parliamentary decree on overall ap-
propriations set a cost framework which resulted, when later
project and order changes are taken into account, in an end
result which was within the bandwidth forecast in the initial
cost estimate. For such a major project, this is not a matter
of course!
Thanks to the intensive political debate in both councils
of the Swiss Parliament and also, later, among the public,
much support was gained for the project which, after the
successful referendum, was started with great impetus.
The renewed discussion of financing in consequence of the
changed economic boundary conditions in the mid 1990s
detracted no little from the initial impetus gained from the
early project-planning phase. The result, however, was a sta-
ble finan cing model which has kept the entire New Rail Link
through the Alps (NRLA) project free of financial difficul-
ties of the kind that beset the construction of the Channel
Tunnel. A high level of private funding, as originally planned,
would inevitably have resulted in an enormous increase of
capital-servicing costs, in view of the unavoidable delays and
add itional investments made in the project. Switzerland was
spared such a scenario thanks to the fund model selected
for financing, with its high non-repayable contributions to
the NRLA projects. Long-term stable financing, also cover-
ing project risks and with reserves for contingencies, is an
absolute must for every large-scale project.
It was clear from the beginning that the project could be suc-
cessfully implemented only with an unequivocal formal com-
mitment by the federal government and with the integration of
the operators’ interests. Fundamental documents, such as the
operating, maintenance and safety concepts, were thus drafted
even before the start of planning of tunnel construction. The
Figs 3 and 4 The new low-gradient railway through the Alps meets a tangible need
Credit: ATG
The financing model selected prevented an enormous
cost explosion, thanks to minimal capital-servicing costs
Credit: ATG
formal order and the mandatory standards were negotiated at
an early stage between the federal government as project spon-
sor, ATG as the constructor and SBB as the operator, and were
contractually agreed before the start of construction.
The Latham report, which was published in England in 1994
and also examined, inter alia, the questions concerning the
management of risks in major construction projects, had not
even been written when the GBT project started. Irrespective
of this, those responsible for the project from the beginning
studied the threats and opportunities of the project at their
own initiative. The zones identified in the early risk analyses
as difficult in engineering terms were surveyed in high-cost
explor ation campaigns from 1993 onward, and thus many
years before the start of actual construction. Without the data
obtained from these exploratory activities, tunnelling through
the northern section of the Tavetsch intermediate massif north
in Sedrun, in particular, would most certainly not have been so
unproblematic as it turned out to be between 2004 and 2007.
Partnership with the contractors was, in particular, recognised
as an opportunity. All were aware that a project of dimensions
never before known in Swiss transport infrastructure construc-
tion could be successfully implemented only on the basis of
constructive cooperation, and most definitely not in the kind of
confrontational atmosphere that prevailed during construction
of the first Gotthard rail tunnel (1872–1882).
This fundamental attitude was expressed not only in corres-
pondingly objective-oriented daily activity on the sites and the
project-planning offices, but also, above all, in the creation of
the dispute resolution bodies for all the main lots. The fact
that the construction work was completed with zero in-court
conflicts is testimony to the smooth functioning of this system.
Such projects can be successfully steered only provided the de-
cision makers have the relevant information in good time and
in easily readable and comprehensible form, and provided free-
dom of manoeuvre is maintained for the warding off of dan-
gers and for the exploitation of potentials. This was clear both
to the client and the constructor, and resulted in the drafting
at an early stage of the ATG project manual and in implemen-
tation of the federal NRLA Controlling Instructions (NCI). Both
are kept to the minimum necessary, but both are meaningfully
formulated documents which were at all times adequate for
the control of investments ranging into the billions. Both docu-
ments illustrate that codes and standards that are understood
by the project participants and are actually lived out in every-
Schweizerische Eisenbahn-Alpentransversale
Anhang 2
zwischen der Schweizerischen Eidgenossenschaft (Bund)
einerseits und der AlpTransit Gotthard AG (ATG)
über Projektierung, Bau und Finanzierung
der Neuen Eisenbahn-Alpentransversale gemäss
Artikel 5bis Buchstaben a und c des Alpentransit-Beschlusses
1. Abschnitt: Allgemeines
Art. 1 Rahmenbedingungen
Die Rahmenbedingungen dieser Vereinbarung ergeben sich insbesondere aus fol-
genden Bundeserlassen:
Bundesbeschluss vom 20. März 199811 über Bau und Finanzierung von In-
frastrukturvorhaben des öffentlichen Verkehrs (FinöV-Beschluss);
Bundesbeschluss vom 4. Oktober 199112 über den Bau der Schweizerischen
Alpentransversale (Alpentransit-Beschluss);
Bundesbeschluss vom 9. Okto ber 199813 über das Reglement des Fonds für
die Eisenbahn-Grossprojekte (Fondsreglement).
Bundesbeschluss vom 8. Dezember 199914 über den NEAT-Gesamtkredit
Art. 2 Gegenstand der Vereinbarung
Diese Vereinbarung regelt das Verhältnis zwischen Bund und ATG hinsichtlich
Projektierung, Bau und Finanzierung der Gotthard-Basisstrecke und des Zimmer-
berg-Basistunnels (ohne Verbindung zwischen der linken Zürichsee- und der Gott-
hardlinie) gemäss Artikel 5bis Buchstaben a und c des Alpentransit-Beschlusses.
11 AS 1999 741
12 SR 742.104
13 SR 742.140
14 BBl 2000 146
Figs 6 and 7 The agreements between the federal government and ATG for implementation of the NRLA
day work are significantly more useful than reams of documen-
tation which will ultimately only be consulted for the purposes
of substantiating accusations should conflicts arise.
The GBT may have become the world’s longest rail tunnel only
in the course of the political decision-making process, but
there was at all times great respect for the task involved among
all project participants, in view of the project’s exceptional di-
mensions and boundary conditions. All were aware that these
conditions demanded tailor-made solutions.
The high underground temperatures, the 100-year service life,
the decision to use the excavated material for production of
concrete-making aggregates and tunnelling in highly variable
ground all resulted in complex task assignments. Solutions were
sought during the project-planning phase with the project en-
gineers, the technical experts and the relevant industries. The
fundamental principle applied that there would be no experi-
ments in the world’s longest rail tunnel and that new technical
solutions would be used only on the basis, and as further de-
velopments, of tried-and-proven methods. The aim, therefore,
was to continue to facilitate innovations but, by contrast, to
have a guarantee of success. In cooperation with industry, high-
quality waterproofing systems and concrete systems, which had
to meet the high requirements, were subsequently developed
and defined. An innovative tunnelling method based to a large
extent on the use of tried-and-proven mining technology was
also developed for tunnelling in the Sedrun section.
Despite the extraordinary requirements, planning of the GBT
proceeded strictly in accordance with the applicable stand-
Fig.8 The evolution of new, tailor-made tunnelling concepts with the inclusion of mining technology
Credit: ATG
Fig.9 Environmental protection enjoyed an extremely
high-ranking status from the very start of the project
( example: the revitalisation of meadow land at Sedrun)
Credit: ATG
ards. These were analysed in detail at the beginning of the
project, with the result that project-specific amendments and/
or augmentations to the relevant standards were kept to the
absolutely necessary minimum. This gave all project partici-
pants the greatest-possible legal security. It is worth noting
that the Swiss standards proved their worth in every way.
Not only the basis provided by the technical codes and stand-
ards, but also the “four-eyes principle” consistently practised
on the client side, was the guarantee that conceptual errors
would be detected and eliminated at an early stage. We can
note, in retrospect, that no such cases actually occurred. The
teams of experts, by contrast, acted as a kind of “rapid-deploy-
ment squad” and were in each case so well integrated into the
project procedure that, in the few cases of out-of-the-ordinary
occurrences, they were quickly able to play a supporting role in
finding a solution to the problem.
All participants were also clearly aware that an undertaking
of such dimensions necessitated the very highest standards of
occupational health and safety. Appropriate selection of the
equipment and methods used had the aim of achieving a sig-
nificantly higher level of safety at work than the then indus-
try average. In order to remove the target level from the field
of speculation during the bidding phase, the corresponding
provisions were explicitly stated as the minimum mandatory
standard in the tendering documentationa system which
proved its worth to the full.
Environmental issues enjoyed an exceptionally high ranking
on this, Switzerland’s largest environmental-protection pro-
ject. On many matters, the basis was not the legally manda-
tory minimum. Instead, in full awareness of the pioneering
role of this project, the obligation to use particulate filters on
the construction machinery, for example, was incorporated
into the contracts before there was any legal requirement
for this.
It was decided, again for environmental reasons, to use the
excavated material for the production of concrete-making
aggregates, making it possible to reduce the volume to be
disposed of by around a third. This was another impressive on-
site success story when one remembers that there was not one
single case of non-conformant concrete quality using these
Consensual solutions were sought for substitute environmental
provisions in dialogue with the appropriate interest groups
with success in all cases.
The contract made between the Gotthard Railway company
and the individual contractor Louis Favre on 7 August 1872
for construction of the Gotthard rail tunnel consisted of just
ten pages an exceptionally “lean” document when one
compares modern contracts for such projects. On the basis
of his offer, the contractor was obliged, to stand up for all
unforeseeable difficulties on his own account and at his own
risk, “which arose in the completion of the works, owing to
the condition of the rock or the mountains at all, as a conse-
quence of extra ordinary water inflows, as a consequence of
elementary events or similar reasons of any kind”. The form
of tunnelling and the masonry lining were, in addition, so nar-
rowly defined that the Gotthard Railway company withheld
payment of instalments for even the slightest deviation on
the part of the contractor, who was several times obliged to
sue for the money. The Gotthard Railway company failed to
meet its contractual obligation to set up the surveying lines
and to perform other preparatory work for construction on
the south and north sides. The contractually specified use of
the drilling equipment from the Mont-Cenis Tunnel could also
not be implemented, since this equipment was not released
by the Italian authorities in Milan and instead rusted away in
an equipment yard in Milan. Favre had no alternative but to
Fig.10 Use of concrete systems defined specifically
Credit: ATG
Fig.11 Use of waterproofing systems defined specifically
for the project
Credit: ATG
accept all these deviations without being credited either costs
or construction time.
This contract, based on our present-day view as unfair, and the
Gotthard Railway’s failure to fulfil its obligations after Favre’s
death and the inevitable court proceedings resulted in the bank-
ruptcy of his company. It is therefore not surprising that the
Swiss Code of Obligations and the Swiss Civil Code were insti-
tuted only a little later in Switzerland. In parallel, the first gen-
eral terms and conditions for construction work were published,
as SIA standard 118, in the form of seven pages of preprinted
contractual conditions consisting of 24 articles, in 1912.
The construction of the Gotthard road tunnel also led to a
court case that almost did not end. The dispute was ultimately
settled many years after the opening of the tunnel by a court
which was not familiar with the situation and had not been
present during the work.
All this convinced the project managers for the GBT project
that the tendering documentation and the subsequent con-
tracts must be fairly drafted and must be as free of contradic-
tions as possible. This opinion was stated publicly at a number
of conferences. The principle was also applied that the eco-
nomically best bid, and not necessarily the cheapest, should
receive the award. Qualitative criteria and price were evaluated
in accordance with previously published rules to determine the
economically best bid. In view of the extremely long contrac-
tual terms, the proverb “so test therefore, who join forever”
enjoyed a very high priority. Careful definition of the suitability
and award criteria, on the basis of risk analyses, was of the
utmost importance in making reality of this. Experience has
shown that the system selected proved its worth and that the
project was completed with suitable and reliable partners.
The Swiss construction industry– led by the Swiss Society
of Contractorsstrongly supported a cooperation based on
partnership from the earliest beginning. These proposals fell
on fruitful soil with the project management for the Gotthard
project. Guided by the aphorism “think in good times of the
bad times”, the drafting of the VSS recommendation on the
resolution of disputes of November 1998 within the mixed-
representation committee (representing the client, the contrac-
tors and the planners) resulted in great mutual understanding.
However, the procedures and negotiations among the project
partners established in the VSS recommendation on dispute
resolution do not lead to success by itself. Suitable people
with experience and the appropriate character, and the ability
to create a basis of trust– were needed on both sides. The con-
tractor had to be able to rely on the fact that his commitment to
deal with extraordinary situations in the risk area of the client is
correctly compensated (including any possible pre-investment).
Without this certainty, it would scarcely have been possible to
avoid work stoppages. The fact that such interruptions, despite
extremely intensive on-site discussions, never occurred is an in-
dication of the equitable partnership actually practised.
The basis for this partnership was provided by a clearly defined
on-site dispute settlement process with the target of motivat-
ing the parties to make efforts from the very beginning of
the work to firstly resolve disputes among themselves and,
wherever possible, on site. This approach required a timely
preparation of the arguments and facts. In cases without
success, the dispute resolution board came into action as a
body offering significant benefits over civil court proceedings.
DrAnton Egli, chairman of the three dispute resolution boards
for the GBT, talks in his article (see XVI 7 “Experiences with the
dispute resolution procedure”) of a “cultural advance”. As he
notes, “The parties keep matters in their own hands, which is
no longer the case in civil court proceedings.” The few genu-
ine disputes and differences, all of which were settled at the
corporate level by means of mutual agreements, testify in ret-
rospect to the correctness of this procedure.
Partnership was also of greatest importance in the relation to
the population affected by the project. The relevant cantons
were therefore integrated into the project by the Federal Office
of Transport (FOT) as early as 1992. Project committees were,
for example, formed in the three Gotthard cantons of Ticino,
Grisons and Uri to act as a communications link between the
project and the affected region. The responsible chief admin-
istrative officers sat on these committees. This alone was no
guarantee of success, however, as the differing results in the
three cantons clearly illustrated. Something which worked in
one canton did not necessarily also lead to success in another.
There were frequently political demands or obstructions, the
solution of which required time and commitment at the high-
est decision-making levels. We may, however, in retrospect
affirm that it is better to make parties affected to participants
than vice versa. The work of all the project committees was
accomplished with constant mutual respect.
Already in the project manual of the project management
AlpTransit Gotthard of the SBB from 1997 was stated that
the constructor has set the objective for an open, active and
honest communication with all parties. Such openness and
honesty is more important than ever before at the present
time. It created a basis of trust between the various partners
and resulted, along with the items mentioned above, in the
partnership which was such an important precondition for
the success of this project.
Fig.12 Equitable dealings and mutual commitment to the
success of the project
Credit: ATG
What recommendations for future large-scale projects can be
drawn from the experience gained on the GBT?
1. Safety first. An acclaimed high standard for occupational
health and safety was achieved; regrettably, nine fatal
accidents nonetheless occurred. “Target Zero” must
be communicated even more intensively as a target
in future, as has, for example, been the case on the
Crossrail project in London in recent years.
2. Risk management must start during the very earliest
phases of the project. The risk management practised
for the GBT was simple, rational and effective. It can be
recommended for imitation without any restrictions.
3. Professional risk management provides a financial evalu-
ation of the potential risks and delineates the needs for
financial reserves for unforeseen contingencies. Such
stated reserves must be used for their intended purposes
and not for any additions to the project.
4. There must at all times be undivided and unified project
responsibility if unnecessary planning and construction
costs are to be avoided (as in the case, for example,
of the retrospectively ordered but never commissioned
traction current route between Amsteg and Sedrun).
5. On-the-spot action is good; consequent control is better.
The water/mud outburst into the Piora exploratory tunnel
could, for example, have been avoided had more con-
sistent, forward-looking action been taken.
6. Logistical interlinking of main lots during the project-
planning phase should be avoided wherever possible.
The necessary strategic freedom of action on the client’s
side can be created and, if necessary, used only given
independent and separate main lots. Combinations
of lots should result from the competition during the
bidding phase and not from technical exigencies.
Numerous unique technical solutions had to be found for
the GBT. Every single choice of material and every single
geometric dimension are thoroughly justified, however. The
solutions selected for the GBT should be adopted by third
parties only provided the reasons which led to the chosen
solution have been understood and accepted, however
(one example is the selection of the tunnel system).
8. Time-related costs generated the majority of discus-
sions with the contractors. It is recommendable, despite
tried-and-proven standard contracts, to regulate this item
more explicitly in future agreements. The principle of
simplicity and of presentation of genuine and verifiable
costs must always apply.
9. The materials management concept selected proved its
worth extremely well; the use of a third of the excavated
material as concrete-making aggregate is exemplary. On
the basis of present-day knowledge, the amounts requir-
ing disposal in the early project phases should be more
generously dimensioned, however. The volume of sludge
requiring disposal was also underestimated, resulting in
costly special solutions, due to the greatly limited landfill
capacities available.
10. Practically in all sections, situations occurred, which
couldonly be mastered with great effort by all parties
involved due to lack of permits or changed ground
conditions which led to changes in the construction
schedule (mater ial management on the north and south
side, consequences of the shifting of the interface
11. The quality inspections specified in the standards are not
sufficient for a mega-project such as the GBT, particularly
in the case of system-relevant products. The client must
consciously stipulate, prior to tendering and on the basis
of the specific risk analysis, which products are system-
relevant and what additional tests and inspections are
12. The overall GBT system became ever-more sophisticated
and complex in the course of project development; the
economically reasonable limits must, at least, have been
reached in this respect. Future projects must examine the
rational level of complexity from the very inception.
Subsystems should, to a greater extent, be capable of op-
eration independent of actual tunnel operation. The fun-
damental principle of “as much technology as necessary,
as simple as possible” should have priority in future, and
should be more stringently applied, in order to minimise
the operating, maintenance and thus the living expenses
of the structures. Construction-related (additional) invest-
ments in design can help in saving future operating and
maintenance costs. Any quantifiable future additional
benefit must be integrated into the corresponding cost
calculations, in order to avoid future restrictions arising for
cost reasons. The tunnel-building generation bears, in this
respect, great responsibility toward the future operating
The opening of the GBT to commercial operation marks
the start of a new chapter in this project’s success story.
Similar heading lengths (Seikan Tunnel) and similarly dif-
ficult geo logical conditions (Simplon Tunnel, Lötschberg
Base Tunnel) have been overcome in past tunnel projects,
but the combination of challenges presented by the GBT is,
with a high probability, unique in the history of transport
tunnel engineering up to now. They were mastered, in the
most diverse situations, with courage, endurance and far-
sighted ness on the part of all involved. The unequivocal
commitment of the decision makers to the higher cause of
project success was tangible at all times, and they never,
even in the stormiest times, wavered in their conviction of
ultimate total success. History has been written and a vision
has become reality. The thanks of the Swiss Tunnelling
Society (STS), representing Swiss tunnel engineering, are
due to all participants:
» To the political authorities at federal level who created a
favourable environment for the project;
» To the authorities of the cantons and municipalities
affected, for their local support for the project;
» To the federal government represented by the FOT as the
project sponsor, for successful coordination of theproject;
» To SBB’s AlpTransit and AlpTransit Gotthard Ltd project
management teams, as the project delivery organisations,
for their professional fulfilment of the role of client during
all project phases;
» To the representatives of the client’s organisation and, in
particular, to the design engineers and local site manage-
ment teams for finding unique solutions and for their great
flexibility in coping with changed boundary conditions;
» To t he c on t ra c to r s a n d a ll t he i r e mp l o ye e s, fo r mastering
newchallenges throughout uniquely long contractual
termson a daily basis, and for their constant adherence
» To the experts, the safety-oriented supervision team and
the dispute mediators for their discreet commitment in
coping with extraordinary situations, in particular;
» To the representatives of the Swiss Accident Insurance Fund
(Suva) and the environmental organisations for finding
constructive solutions to unique challenges.
This success would not have been possible without the heart-
felt commitment of all participants. Our greatest thanks there-
fore go to the several thousand workers and partners who
were involved in the project.
Our work is done– let operations begin!
Fig.13 The project was carried out with the greatest commitment by all involved; our thanks are due to all who worked
onthe GBT
Credit: KEYSTONE, Gaetan Bally
We ventured a lot– together.
We achieved a lot– together.
Because we know: the mountain is big; we are small.
Federal Councillor Moritz Leuenberger, 15 October 2010
Fig.14 Trial run through the GBT
Credit: ATG
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