Google Inc.’s plan to build high-tech “Google Barges” in Portland and San Francisco was abandoned after Coast Guard officials in San Francisco repeatedly raised fire-safety concerns about the unusual vessels, according to Coast Guard emails obtained by The Wall Street Journal.

Google stopped work on the San Francisco barge in September 2013, a month before a near-identical barge arrived in Portland Harbor.

The barge contractor in San Francisco, Foss Maritime Co., ran into problems after the Coast Guard inspected the vessel and found it would carry more than 5,000 gallons of fuel on the main deck and a substantial amount of combustible material on board. Coast Guard officials were also worried about how people could escape the four-story structure, which was made out of shipping containers.

In September 2013, a Coast Guard inspector wrote that more safety measures were needed in case “people are forced to jump overboard on the waterside (like a fire),” according to an email The Wall Street Journal obtained under the Freedom of Information Act.

Google stopped work that month after the Coast Guard gave the contractor a 20-page document laying out fire-safety requirements and a spreadsheet with escape requirements.

It appears that no work was ever performed on the barge in Portland. The structure’s top – which was made by assembling 63 shipping containers – was built in New London, Connecticut. Both barges were envisioned as floating showrooms for Google Glass and other high-tech gadgets.

When the barge arrived in Portland in October 2013 from New London, it was moored in Portland Harbor at Richers Wharf, a facility owned by contractor Cianbro Corp., which was expected to work on the project.

Cmdr. John Humpage, who heads the prevention department of the Coast Guard in northern New England, said Coast Guard officials boarded the barge shortly after it arrived in the harbor. He said staff did not inspect the unusual structure because the meeting was intended only to provide an introduction to the project.

He said the Coast Guard never returned to inspect the barge because no work was ever done by Cianbro.

The barge was towed out of Portland Harbor in August of this year, and the top structure sold for scrap. The barge itself was sold to be used as an ordinary barge. Its whereabouts today are unknown.

The barges gained national attention, in part, because of the secrecy surrounding the project. The Coast Guard signed nondisclosure agreements with Google that prevented the armed forces branch from talking about the project. According to the emails, Coast Guard officials later regretted signing the agreement after the barges captured enormous media attention.