ITAGUAÍ-In a vast hangar, Brazilian technicians work on the enormous cylindrical hulls of two submarines, but in a country buffeted by economic crisis and corruption the vessels already face stormy waters.

The hangar at a naval facility in Itaguai, south of Rio de Janeiro, is 125 feet (38 meters) tall, an impressive structure where the future submarines, lying in separate sections, are being equipped before eventual assembly. In all, five submarines are planned, one of them nuclear-powered, with the first scheduled for launching in July 2018.

The bid to transform Brazil’s small submarine fleet was won by French group DCNS in a 6.7 billion euro ($7.1 billion) contract signed in 2009 to bring in its technological know-how and also to build a new naval base and shipyard at the site.

The plan is to phase out the five submarines built with Germany between 1980 and 1990 and give the navy a boost in its main job of patrolling Brazil’s 5,280-mile (8,500-kilometer) coastline.

But for all the ambition and foreign help, Brazil’s submarine-building voyage is falling behind schedule.

The first conventional vessel was meant to have been launched this year while the nuclear sub - being built exclusively with Brazilian technology - is five years behind schedule. Although the planning stage for that submarine is completed, construction will not start until 2021, with launching in 2028. The base and new shipyard are just over 60 percent finished.

Latin America’s biggest country is into its third year of recession and a huge embezzlement and bribery scandal has turned politics upside down, while exacerbating the economic woes.

At the heart of that scandal is Brazilian construction giant Odebrecht, which has been targeted by prosecutors over its central role in fleecing state oil company Petrobras and making illegal payments to political campaigns. And Odebrecht is DCNS’s partner in the submarine project. Currently some 1,650 workers in Odebrecht overalls are working at the site. Back in 2014 there were more than 6,000, said Admiral Gilberto Max Hirschfeld, who oversees the construction.

Odebrecht’s involvement in the submarine project has also been caught up in the corruption scandal, but Hirschfeld said “the investigation does not affect the shipyard.” The problems with keeping up to schedule are caused by “having to slow down as a result of budget shortages,” he said. “But we’re focusing all our efforts on the first launch taking place in 2018.”

A big moment will be when the first section of the first hull is transported to the shipyard for final assembly, using a 2,230-foot (710-meter) tunnel that has been cut through the mountainside to link the factory hangar and new base. The enormous scale of the project and expense is all worth it for Brazil, the admiral said.

“Brazil’s riches attract a lot of envy and we don’t know what will happen in 50, 100 years,” he said.

He also downplayed the problems of delays, pointing out long waits in DCNS’s construction of a new Barracuda line of nuclear subs in France.

“The country is going through difficulties, but it’s entirely manageable,” said Eric Berthelot, director of DCNS Brazil.

“It’s a strategic development for the country. We’ve seen the economy’s evolution these last few years and today there are signs of improvement,” Berthelot said.