Your eyes aren’t experiencing signal trouble — those really are Maryland trains picking up commuters this summer on the Port Jefferson line.

The Long Island Rail Road leased eight cars from the Maryland Area Regional Commuter system for the first time to expand its fleet and alleviate summer crowding, officials said. The pilot program cost the railroad $670,000 and will last through the end of the summer.

But riders on social media still have questions about the temporary cars. Namely, what’s up with the vintage fixtures?

In tweets, passengers have described riding in the cars with quips like “Went back in time today” and “seems to be owned by Maryland Dept of Trans in 1950s.”

MARC did not respond to a request for comment. It’s unclear how old the cars are, though the LIRR said the cars would normally be in circulation down south.

Among the quirkier things found on the trains: a red box posted by commuter Twitter account @LIRRMisfits labeled “fusees and torpedos.”

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It’s indeed a relic from the past but “torpedos” aren’t what the name implies. Torpedoes and fusees are largely obsolete methods for conductors on different trains to communicate with one another, said Don Fisher, president of the Railroad Museum of Long Island.

Conductors facing train troubles could place the small explosives known as torpedoes along the tracks behind their stopped train. The wheels of other trains would set off the torpedoes, which were invented in the 1870s, so those conductors knew to stop, Fisher said. The LIRR said they no longer use torpedoes and the MARC train boxes are empty.

“They can be dangerous to handle and with air conditioning and enclosed engineer cabs, they are no longer an effective signaling device,” Fisher said.

Fusees are visual markers, similar to road flares. These, too, are less common in 2017 and generally used as a last resort for railroads like the LIRR, since conductors can now use radio communication, GPS and other systems.

Despite initial reports of no air conditioning, the LIRR said the MARC trains are equipped to keep the cars cool.

“We’ve received scattered complaints of their effectiveness on the hottest days this summer,” officials said in a statement. The systems undergo daily maintenance.