Steam Train Fanatics Are Rebuilding This Mythical Speed Record-Chaser From Blueprints

The T1 was a streamlined monster that could achieve 100 mph.

byJames Gilboy| PUBLISHED Oct 3, 2022 2:30 PM
Steam Train Fanatics Are Rebuilding This Mythical Speed Record-Chaser From Blueprints
Museum of Science and Industry, Chicago/Getty Images
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In November of 1945, the Pennsylvania Railroad rolled out the T1: the first of its new class of high-speed steam locomotives. Penned by the same hand that gave us the Coke bottle, the T1 was built during the golden age of steam power to sustain 100 mph in passenger service. Rumor has it, though, that it could—and did—go faster, much faster, with some models claiming speeds in excess of 140 mph. That'd be a world record if anyone could prove it happened.

But no one can. The day of the first T1's debut coincided with the delivery of the PRR's first diesel locomotives in an omen of what was to come. By the end of the 1950s, the T1s weren't just retired; all 52 were gone, scrapped to the last unit. Neither their status as icons of steam power's last hurrah nor their allegedly record-breaking top speeds were enough to earn even one the mercy of preservation. Today, the T1 lives on in nothing but archived film reels and leaves the question of whether United States steam, not Britain's 126-mph A4 Mallard, really deserves the title of world's fastest steam locomotive.

PRR T1 prototype departing Chicago in February 1943. Library of Congress

Or maybe not. Inspired by the resurrection of the formerly extinct LNER Peppercorn Class A1 locomotive, which had all of its original units scrapped, a growing group of international railfans is pooling its money to build a new T1 from the ground up. It's already approaching halfway done, but has a long, long way to go before the 53rd T1—5550—fires up, let alone chases any world records.

Reconstructing a T1 is the endeavor of The T1 Trust, a nonprofit that has, since 2013, been collecting the funds and expertise necessary to replace the institutional knowledge that died with the steam age. But even with its accumulated brainpower, original blueprints, and funding, progress is fated to be slow, as the T1 was as complicated a machine as it was immense.

The hulking iron horse measured in at about 122 feet long, 16 feet high, and weighed about 428 tons. Each drive wheel measured 80 inches across (that's six-foot-eight), and there were eight in total, in a 4-4-4-4 duplex-drive arrangement. That means four unpowered leading wheels, two separately powered sets of four drive wheels, and four trailing wheels—unpowered on production models, though a prototype apparently had another pair of steam cylinders powering them, too.

Being duplex-drive, both its sets of driving wheels were affixed to the same rigid frame—they weren't articulated in between like Union Pacific's famous Big Boy and Challenger. They were turned by a quartet of double-acting steam cylinders with a 19.75-inch bore and 26-inch stroke—that's a 522.1-liter four-cylinder in car parlance—under a force of 300 psi of steam pressure. The result was almost 65,000 pounds of tractive effort, or about what Amtrak's new diesel-electric Siemens Charger produces, but around 50 percent more horsepower—up to 6,665 of them at 85 mph. Such was the T1's power that the locomotive became infamous for spinning its wheels, though throttle-happy crews apparently deserve most of the blame.

Between that and a streamlined body designed by Raymond Loewy of Coca-Cola bottle fame, the T1 was capable of maintaining 100 mph during high-speed passenger service. (At that speed, its monstrous drive wheels turned 420 rpm, or seven times a second.) Beyond that mark, however, T1s' reliability suffered, in part due to the design of their poppet valves, which were apparently both prone to cracking and difficulty of service. Nevertheless, rumors suggest T1s could far exceed that speed, with former Smithsonian transportation curator William Withuhn allegedly publishing an anecdote of a T1-pulled train breaking 140 mph. Obviously, such a tale is impossible to verify, as the T1 would be a record-holder if its supposed top speed could be proven.

In theory, though, The T1 Trust's T1 number 5550 could be the one to do it, as it'll receive multiple period-appropriate upgrades that'll improve its high-speed reliability. In that sense, as the members of Trust say, 5550 is less a replica than a continuation, hence a production number following 5549: the final original T1 built.

It'll be the best of the bunch, too, as Trust members explained in a YouTube highlight that the problematic poppet valves will be switched to camshaft-driven rotary valves, thus simplifying service. Accommodations will also be made to upgrade from coal to fuel oil, like Union Pacific's restored Big Boy 4014 did, or whatever fuels make sense in the years to come. These, along with the rest of the design tweaks, will be rigorously tested in simulations before any record attempt is made.

But the Trust knows not to put the car before the horse, or in this case, the tender before the iron horse. It first has to actually build the locomotive, which it has almost no historical reference parts for but does have pretty much all the technical documentation required to recreate it. According to the group's website, progress stood at 39 percent completion by tonnage as of January, much of which has come from securing an appropriate class of tender that'll be refurbished and streamlined. That also saved up to $3 million on construction costs.

The rest, however, the team's had to do the hard way, like reconstructing the T1's 68-foot frame. Instead of casting it in one piece like the originals, the team is having to weld together segments—a method made viable by advancements in welding technology. Various parts are slowly being manufactured across the country and being shipped to Pennsylvania for installation, while recent Trust social media activity (above) shows the boiler is coming together.

But the going is slow, and for the most predictable reason of all: Money. Despite having raised over $1.6 million to get the project to where it is today, the Trust still has more than halfway to go, and at its current pace, doesn't expect to be finished until late this decade at the very earliest. In other words, all hope of even a single fire-up—never mind a world speed record attempt—is contingent on people stepping up to pay the T1's way. If those of us who care want to bring about the biggest W for steam preservation since the Big Boy's rise from the ashes, we must put our money where we foam from.

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