Leaders of the Rail Maritime and Transport (RMT) union said its members will strike for four days from 19 June and for seven days from 29 June. Maintenance staff acted after private firms refused to meet their demands over pay and conditions.
Jimmy Knapp, general secretary of the RMT, accused the engineering companies of asking for "too much in return for too little compensation" under proposals to restructure pay and conditions.
The decision to strike was taken yesterday by the union's executive after more than 9,000 members - out of a possible 13,000 - voted for industrial action during earlier ballots.
Mr Knapp said the strikes would have a "considerable impact" on services. "The RMT is determined that privatisation is not going to mean exploitation. The companies are asking far too much from their staff for too little in compensation."
Railway privatisation saw the rail network sliced up and sold off to the private sector. The British Rail Infrastructure Services was no exception and unions fear the nine companies that maintain the railways will cut many of the benefits staff enjoyed under state control.
The RMT says the companies, which include Jarvis and Balfour Beatty, are being greedy.
Union officials pointed out they made a combined profit of pounds 300m last year, yet wanted a deal at the lowest cost.
Some workers will lose up to pounds 40 a week despite being forced to work more unsociable hours, says the union. The RMT argued that its members were entitled to pay rises, a 35-hour week and improved sick pay and holiday arrangements in return for accepting the new terms.
Workers involved in the dispute maintain track and equipment, including signals, sleepers and rails.
Mr Knapp said that there will be an immediate effect on services when the strike starts which will become "progressively worse". Experts say that as the dispute drags on more sections of track will need speed restrictions as vital engineering work is not done.
Railtrack, the company that hires staff to maintain the rail network, expected the impact to be "minimal to begin with".
Traffic slowed to a crawl yesterday as a lorry drivers' protest and a serious accident blocked routes. There were long tailbacks on the M6 in the West Midlands, and delays in Kent and central London, as drivers protested about the level of duty imposed on diesel fuel in Britain.
They say that cheaper diesel on the Continent is helping competitors to take their business.
Meanwhile, a 15-mile stretch of the M5 in north Gloucestershire was shut after a lorry hit a bridge near Tewkesbury, killing the driver.