End of February, the 26,455 m bore of the Hakkoda tunnel in Japan holed through. Today, the 34,577 m Lötschberg Base Tunnel in Switzerland was blasted through (image above). Any time soon[UPDATE: on 5 May, see this pdf in Spanish], the 28,377 m twin bore of the Guadarrama tunnel in Spain will be finished. When opened, these will be the 5th, 3rd and 4th longest rail tunnels in the world.
A good ocassion for some analysis of tunneling, with an eye on issues like high-speed rail & subways, the economics and other benefits of such projects, and (you guessed it) public vs. private projects.
There is a trend of cutting across whole mountain ranges: three more tunnels in excess of 50 km are in works, all of them rail, in the Alps and with a target date around 2015; and there are half a dozen other very long tunnels readied. Some new lines, like the quadruple-tracking of the Inn valley line in Austria and the Bologna-Florence high speed line, will run almost completely in shorter tunnels. A multitude of smaller tunnels complements the picture of the subway-isation of railways.
What enabled this is technological development -above all, TBMs (tunnel boring machines). There are six manufacturers of name: market leader is the young German company Herrenknecht, then there is Wirth, another German company that swallowed French NFM; two Japanese companies: Kawasaki and Mitsubishi Heavy Industries; then the firm of an Italo-Canadian, Lovat, and finally the US firm that made hard rock TBMs commercially successful half a century ago, Robbins.
The latter firm is interesting. First, it is currently employee-owned. Second, while it doesn't make the largest (up to 15 m in diameter) or most advanced (fitted for more challenging or changing rock types) TBMs, its products were efficient enough in favorable strata for the firm to proudly claim almost all TBM advance records.
Often cheaper than TBM is blasting (or, as in its modern form it is called, the new Austrian tunneling method (NATM)) - however, it also gave the top entries in modern tunnelings' Hall Of Shame.
High-speed rail & subways
Two main drivers/beneficiaries of this feverish tunneling. (Tough road tunnels, especially in Norway, undeniably also are.)
For high-speed rail, The Year will be 2007. While European projects suffered many delays over the last one-and-half decades, of the two dozen lines currently under construction, half are due to open in or close to that year. Of these, only the French TGV Est is without major tunnels.
While nowadays in West Europe it is fashionable to hail light rail as the way of the future, its lesser capacity and speed (having to stop at crossroads) means that in larger cities, it can never replace, just supplement a subway system. This has apparently dawned on some - Paris is extending again, Madrid, Barcelona, Athens and others continue to grow apace.
But most development takes place in East Asia. The Chinese concrete heads realised in the last few years that copying US car culture will only lead to permanent traffic gridlock in smog. Thus began the construction of subways at breakneck speed - Shanghai, Beijing and Guangzhou are to get systems on the scale of the currently largest, and a dozen other cities also build theirs. In Japan and the Tigers there is construction too (the Seoul - Tokyo duo are edging closer to the leading but sclerotic New York - London pair).
Staying within budget
What can drive up the costs of a major rail project with tunnels? Based on the many I reviewed:
- Delays. IMO the main source of extra costs: means more spending on workers' pay, rent, interests, paperwork [repeated tenders etc.]; while there is inflation, and potential customers lost - yet there are countless examples of owners thinking it's cheaper to, say, pay $100 million for four years than pay $150 million for two years.
- Cost cutting. Yeah. It's when you spare €10 million in preliminary geological research, and end up paying €200 million to master an unforeseen fault zone. Or rationalise away safety exits, which are then prescribed by a new EU directive and have to be added with extra planning costs.
- Lack of coordination. When one part of the project has to grind to halt because another is not finished, when there are unfinished legal problems, when the goals are changing or there is wrangling about them at the top, when project leaders are incompetent. When feeder projects aren't pushed to be finished right along.
- Corruption. Not really separate: the level of this one is correlated with that of the previous.
- Prestige/special interests. Where a public transport project is no longer public: when a project is more shaped by a leaders' intent to show off or others' demands.
- Finally, unforeseeable construction problems. Tough often used as the culprit, when so usually to hide some of the previous - I'd put them in last place. (A recent example.)
The tunnel-cracking substinence of the instable valley side on which the high speed line descends toward Barcelona, or the mess at the Sigaue-Tunnel (see  again), are examples of problems not unforeseeable but due to silly cost cutting, despite warnings. The line of the latter, Cologne-Frankfurt/M, also exhibits two expensive stations for rural towns, which see minimal passengers but cause too long a travel time - they got there on the insistence of prestige-minded PMs of crossed provinces. And with some US projects, I have to wonder whether even the planners had a transport line as goal.
As a contrast three examples of doing it right.
- First, what Maggie Thatcher prevented, Major and Bliar supplemented: the Channel Tunnel Rail Link (CTRL). This is a public-provate partnership (PPP) project, but with most of the money coming from the state(s), and high-speed rail engineering experience from French firms involved in TGV projects. The remaining, 39 km second section takes the line under the Thames in a shorter double tunnel, and crosses London in 19 km of double tunnels (whose boring finished a year ago). Also involving three stations and an adjacent new suburban railway tunnel, the project stays in its original budget of £3.3 billion ($6 billion) [tough PPP might have racked up the original budget].
- Second, in Switzerland, the Bahn2000 project was a complex programme of upgrading key parts of the whole domestic network (plus more trains for a more frequent, better linked service). Its centerpiece was Switzerland's first high-speed stretch, 45 km long, with one third in tunnels. All upgrades and the enhanced timeplan are in service since last December, and Bahn2000 stayed far below budget: CHF 5.9 instead of 7.4 billion (€3.85 resp. 4.8 billion).
- But the really impressive feat is Metrosur (in English see this), a 41 km ring subway for three southwestern suburbs of Madrid: planned, tendered, tunnels bored, fitted, track laid, trainsets bought, commissioned - all this from €1.143 billion and less than four years!
Overall economics & Other Benefits
Of course, building within budget is only one half of the economics - the other is getting back value once construction finished. What can go wrong here, beyond faulty projections: delays in connecting projects and pricing. The latter is another such thing that should be obvious, but those responsible repeat the same error just too often: they try to set prices just this side of intolerable, so travellers/transporters stay away, traffic and income rises only after cuts.
Furthermore, one shouldn't watch the quartal numbers of major (public) transport projects, their timescale is decades. Spain's first high-speed line, once decried as a useless prestige object for the Expo '92 in Sevilla, turned profitable after five years (in 1997), that profit grew, first years' losses were covered just four years later. One can think in even longer terms. The original Lötschberg tunnel had major construction problems, the worst when the northern bore hit a giant aquifier (tunneling had to be re-started along a diverging non-straight route). Plummeting traffic (due to WWI breaking out just after opening) helped to make it an unmitigated financial disaster. Then. But today, it is the centerpiece of a busy freight corridor, run by a profitable railway company.
This leads us beyond economics. Most of the superlong tunnels aren't expected to be profitable in a narrow economic sense. Some, just like subsidized air traffic, is expected to spurn business. Others are meant to spare along-the-way inhabitants the noise or the inconvenience of being cut off, including non-human inhabitants. Reducing CO2 emissions by getting traffic off the roads or planes is another benefit.
The place where this is most apparent is the land of direct democracy, Switzerland. There, on a number of referendums on expensive transalpine and local rail network projects (whose centerpieces I dealt with), invariably the "Yes" vote won. What's more, last year both a populist proposal and the government's 'alternative' version on re-starting road & highway construction was voted down. And a month ago Swiss parliament defied the government that thought the Swiss programme to connect to the European high speed network is the right place for budget cuts, voting down the proposal of delaying half the projects. (Contrast this with governor Jeb Bush's success in turning Florida voters against high-speed rail with sustained lying and propaganda.)
Public vs. private
I think it is quite obvious: those who lament about the efficiency of the public sector with examples in this field (i.e. transport projects, specifically with major tunnels) are half-eye-blind. For whatever is the record of public-owned projects, the record of the private sector is an absolutely dismal one: there is one real example (Eurotunnel) and they blew it, their involvement in PPP schemes usually led to price hikes at the planning stage and projects going ahead only after sizable state contribution, and of course the default is that they falter or don't even try.
Worse: many of the recent examples of public-sector-owned major projects doing something wrong are, in fact, examples of politicians and administrators trying to copy en vogue private sector methods and ideas.
In my opinion the most important factor in making such a big, complex project a success is dedicated decisionmakers with oversight - be them the project managers, or state/province/city transport ministers, or a PM/major, or railway bosses.
For public-owned projects, the frequency of the right people in the right places tells something about the quality of democracy there (or, ehm, the level of the dictator's enlightedness...). But for private projects, there are intristic problems even beyond the capitalist-vs-public conflicts of interest: the big-profit-fast mindset, the tendency to sub(-sub-sub-sub-)contract, the preference - and hence training - of keeping everything simple (such big projects just aren't simple), and the tendency to jump on whatever meaningless-catchword-loaded bandwagon economists prefer at the time.
 Of the currently five road or rail tunnels above 20 km in the world, the only road tunnel - the 24,510 m Laerdal tunnel - is fourth, and three are Japanese.
 They are: the 57,051 m Gotthard Base Tunnel (GBT) in Switzerland, a third of which is already excavated, the 55 km Brenner Base Tunnel (BBT) between Italy and Austria, and the 53.1 km Mt. d'Ambin Base Tunnel between Italy and France (for the latter two preparatory works are in progress). The connecting lines of all three will have shorter, but still up to 15 km tunnels which roughly add up to another 50 km (of these, the BBT southern connection is covered elsewere than the main link).
 The Transpyrenean and the Trans-Gibraltar-Straits tunnels (both 42 km and in state of geological research), the 32.8 km Koralmtunnel in Austria (preparatory works), the 24,667 m Pajares Base Tunnel in Northern Spain (excavation started), and the 22,225 m Iiyama tunnel in Japan (blasted since 1998).
 Some 43 out of 55 km on the Inn valley line, 73 out of 78.5 km on the Bologna-Florence line. They aren't without precedents: tunnels make up 102 km of the 130 km central section on the recently earthquake-stricken Joetsu Shinkansen; and 44 out of 50 km on the as-yet-waste-of-money (winds up along an Alpine valley in Italy towards Austria, with no similar-speed and -capacity line to continue it beyond the border) Pontebbana in Italy, finished in 2001.
 Note tough: they are a bit not up to date regarding others' records - mostly for larger diameters.
 The worst of the worst is the Hallandsås tunnel in Sweden: first bored with TBMs too heavy, then came blasting - to stabilize soil, a chemical was injected into the soil, which poisoned cows grazing above... Now it is finished with TBMs. Another is the Siegaue-Tunnel on the Cologne-Frankfurt/M high speed line in Germany, which runs under a city, and had to be stopped three times, having caused damage to buildings and a cementery.
 Near-complete list: in Spain, (1) the Madrid-Valladolid line (the Guadarrama tunnel is on it), (2) the Galician corridor, (3) the Córdoba-Málaga line and (4) the final section into Barcelona; (5) the Milano-Bologna and (6) Bologna-Florence lines in Italy, (7) the TGV Est in France, (8) the Channel Tunnel Rail Link section 2 to London, (9) the Liège-German border and (10) Antwerp-Netherlands (HSL Zuid) sections in Belgium/Netherlands; (11) the Ingolstadt-Nuremburg line in Germany, and (12) Botniabanan in Northern Sweden. High-speed trains will also use the above mentioned Lötschberg Base and Inn valley lines.
 But for cities of a few hundred thousand, light rail is good enough. Especially if trams are enabled to continue beyond city borders on railway tracks, maybe deviating again on light rail tracks in agglomeration towns (the highly successful "Karlsruhe model").
 I note I don't consider environmental issues a 'special' interest, and if local residents protest that is often not a case of NIMBY but planners planning above others' heads without asking them. I more think of stuff like routes serving a small rich area or avoiding a rich man's estate.
 These two made me shake my head: (1) The Boston's North-South Rail Link, linking two railway terminals with a 1 mile tunnel, using in part tunnels already built along with that road-building disaster, the $15 billion Big Dig, is tagged to cost $8.7 billion. That's 40% more than the entire Channel Tunnel Rail link, despite the latter involving ten-times-longer, all-new under-city tunnels, fitted for high speed. (2) The River LINE: an existing 34-mile line merely brought in shape and diesel multiple units purchased to run on them, with $1.1 billion spent. No tunnel involved, but just too absurd: in Europe we'd build this much from at most €100 million [a 17 km/€14.6 million German example], while a complex upgrade into an electrified-double-tracked, half as long suburban line with under- and overpasses, near Frankfurt/M, was done from just €309 million.
 This shall not be taken as an implication that Bliar deserves praise: the predictable (and predicted) disasters his government created with rail privatisation and the West Coast Mainline upgrade, plus the PPP idiocy with the London Underground make his record extremely negative - even without mentioning his broken pledges on road construction.
 By profitable I mean the operating surplus paying back debt and still more remaining; the operating profit - income from tickets minus operating expenses - is usually wildly positive for high-speed rail.
 A similar poke-in-the-eye (of neoliberal fundies) is to call privatisation the Least Efficient Activity of the State.