Blanka Two

5 December 2016

Rumblings from the City Hall of Prague suggest a new tunnel complex may be planned for the Czech capital. The story was broken in late November by the economicsfocused Prague daily newspaper ‘Hospodárské noviny’. The project hopes to complete the Prague’s inner ring road and resolve the city’s traffic problems. According to the newspaper, around CZK 80M (USD 3.14M) has been put aside for design and study preparations in 2017. Of course the Final project will be far more, around CZK 50bn (USD 1.97bn) according to early estimates.

Although Petr Dolínek, deputy mayor of Prague, who has responsibilities for transport and finance, admits that the project could come in significantly more expensive.

The alignment is still unknown, but it will connect to the existing Blanka complex. Which could make things interesting on the public relations front. The earlier 5.5km Blanka tunnel project saw cost and time overruns following several collapses. In 2010 a 15m crater resulted from a collapse, which temporarily buried an excavator with its operator – who was thankfully recovered without injury – and in 2008 the ground fell through in a public park causing a 20m crater.

In 2011 it was announced that the cost of the project would increase by CZK 10bn to CZK 37bn (USD 2.08bn in 2011) and the topic became politically charged with the sitting administration blaming its predecessors and vice versa. The project eventually opened in 2015, four years late, but the infrastructure is in place.

Now, Dolínek sets his sights on the missing piece of Prague’s road system, and wants to see it completed within 10 years. Although Hospodárské noviny quotes a representative of Satra, a company involved in the design of Blanka who suggests that a planning period of six or seven, maybe even more years is realistic. Blanka preparations reportedly lasted 12 years with construction running another eight. Dolínek, then, may be an optimist. But political support for tunnelling is usually a good sign.

Of interest to engineers on the ‘Blanka Two’ project, and surely the focus of future articles, is a section of road near the river, Povltavská Street, which is too narrow for the desired four lanes. Designers will need to resolve this. Reportedly the solutions are likely to be a two-level surface road, a double-deck tunnel or a surface road and tunnel road combination.

It is this area that gets gridlocked at the slightest disruption, and a tunnel is still a preferred solution for Prague