A powerful but homely creature, Snowzilla sounds like 10,000 hair dryers running at once and resembles a cross between an aardvark and a tollbooth. It sits on railroad wheels, weighs 26,000 pounds, and measures 8 by 12 by 27 feet — though most of that length is taken up by its elongated snout. Its thirst for fuel is so great — it guzzles 900 gallons in a single run — that a tanker truck must follow it from station to station.

Although the rest of the MBTA system is cleared with “snow trains’’ — ordinary trains and trolleys that run continually to keep snow from accumulating — the Mattapan line is a special case. The motors mounted beneath its trolleys short out in extreme snow conditions, so the T suspends the line whenever heavy snow buries the tracks, running substitute shuttle buses until Snowzilla can do its work.

When Snowzilla works, it can clear the 5 miles of track on the Mattapan line in under five hours, a feat that might take all day with a team of laborers wielding conventional equipment. Its given name is the Portec RMC Hurricane Jet Snow Blower, model RP-3, and at its heart is a jet engine transplanted from a Korean War-era fighter. The engine is capable of generating 3,000 pounds of thrust and reaching a temperature of 1,000 degrees, and its exhaust is directed down a chute to blast snow from the Mattapan line.

Snowzilla is reserved for the gnarliest storms, enlisted only when at least 6 inches of snow falls, and even then it is a judgment call; it sat out Friday, when about half a foot of fluffy powder fell in Boston.

“It goes right into our core,’’ said Secretary of Transportation Jeffrey B. Mullan. “We consider it a critical service.’’

The Mattapan line carries just one-third of 1 percent of the MBTA’s 1.3 million daily riders, but the T is determined to serve the urban neighborhoods along the Mattapan line, whose trolleys also function as connectors to the Red Line and several high-ridership bus routes.

Snowzilla, one of the more unusual pieces of equipment in the MBTA’s toolshed, has a singular task — clearing the Mattapan High Speed Line during heavy snowstorms. But it is essential for the 4,500 riders a day who rely on that line’s 10 lovingly restored, 1940s-vintage streetcars.

Also, neither one is truly invincible. Godzilla was defeated by the Oxygen Destroyer. And Snowzilla was felled by the last big snowstorm. An elbow joint cracked twice in a span of eight hours, rendering the snow-clearing machine motionless and forcing the T to call in a front-end loader for relief.

The thing about Godzilla and Snowzilla is that, appearances aside, neither one really breathes fire. Godzilla shoots atomic rays that only look like fire to the uninitiated. Snowzilla shoots a jet of gas that obliterates snow from railroad tracks, only occasionally belching fire if you use it wrong.

Deployed just one or two days a year, and some years not at all, Snowzilla spends most of its time parked in a drab, anonymous garage at the far end of the MBTA’s Cabot Yard. It is inspected and started every few weeks to keep it ready.

For the bulk of its 32 years, Snowzilla toiled in obscurity, but lately it has had a taste of celebrity. Mullan, a Milton resident who lives near the Mattapan line, rates it as his second-favorite piece of equipment among the thousands in the state’s arsenal, surpassed only by a bucket truck with an extraordinary arm that is used for inspecting the underbelly of the tallest bridges.

After a post-Christmas storm dumped 18 inches of snow, Mullan tweeted pictures of the jet blower in action and uploaded a blurry cellphone video to the Department of Transportation’s YouTube account.

Soon, MBTA spokesman Joe Pesaturo could be heard declaring his fondness for the creature he dubbed “Snowzilla’’ — until that point, it was known only by its technical name — and Richard A. Davey, the T’s general manager, embraced the colorful moniker. During the next major storm, he touted Snowzilla as an emblem of the T’s snow-fighting efforts during a mid-storm appearance on the local news.

But the attention may have been too much for Snowzilla, which at that same moment was approaching the Mattapan terminus in near-whiteout conditions. It arrived amid a haze of gas fumes and a cloud of debris — snowballs, stones, and frozen clumps of dirt, pop-popping in every direction. Workers clearing platforms and walkways at the nearby station put down their shovels and stared. But something was amiss: Snowzilla was leaking No. 1 kerosene, and a trail of fuel — dyed a distinctive pink — stretched to the horizon.

A mechanic driving the accompanying tanker diagnosed the problem: a crack in a finger-shaped fitting where the fuel line meets the jet engine.

It would turn into an all-day delay. Back at the T’s Charlestown garage, machinists Mark James and Sergio Iannino e-mailed pictures of the cracked part to Olie Ericksen, a turbine technician in the northwest corner of Pennsylvania who specializes in rebuilding and repairing jet-engine snow blowers.

Ericksen is believed to be the only person in his field. The jet blowers, perhaps 100 of which were manufactured from the 1960s through the ’80s, became essential equipment for cold-weather railroads, but most railroads needed just one or two; the sales market quickly ran out, because the jet blowers were used so infrequently that they almost never needed replacing, provided they were maintained.

Most railroads deploy them exclusively in yards to clear the critical switches that connect webs of track and that can fail when packed with snow; given the fuel demands, most do not use the blowers to clear long stretches of track such as the Mattapan line, according to Ericksen.

The T ordered two in 1977, after a series of extraordinarily snowy winters, and they arrived the following year, albeit too late for the famed Blizzard of ’78, according to Bradley Clarke, the transit historian who serves as president of the Boston Street Railway Association.

Snowzilla’s twin is still used at the main Orange Line yard at Wellington to clear switches, but its engine has been stripped and rebuilt, meaning only Snowzilla retains the complexities of its original Westinghouse J34 — including an aviation pump and fuel controls to account for high speeds and extraordinary altitudes.

But the problem Jan. 12 was a simple one that could have happened at 40,000 feet — or 4 feet: a crack in an old piece of metal. The storm made it impossible for Ericksen to send a replacement the same day. The T machinists welded a patch, but when that patched part finally made it back out to Mattapan — across snow-addled roads — and was fastened to Snowzilla, it cracked again. Back at the shop, James and Iannino started over, attempting to fabricate a replacement from scratch. With the sun setting and the tracks still snowbound, the T eventually dispatched a front-end loader to try to clear the Mattapan line.

Michael Reddy, a supervisor with the T’s maintenance of way division, ordered Snowzilla to retreat to Cabot Yard, defeated. But then the machinists jury-rigged a replacement, and it arrived in Mattapan after nightfall. Like Godzilla reemerging from Tokyo Bay, Snowzilla roared back to life, determined to finish the job.

Eric Moskowitz can be reached at emoskowitz@globe.com.

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