T1

4 Articles

Welded frame and cylinders for T1 #5550

Building A Steam Loco These Days Is Nothing But Hacks

January 1, 2026 by 34 Comments

The Pennsylvania Railroad (PRR)’s T1 class is famous for many reasons: being enormous, being a duplex, possibly having beaten Mallard’s speed record while no one was looking… and being in production in the 21st century. That last fact is down to the redoubtable work by the PRR T1 Steam Locomotive Trust, who continued their efforts to reproduce an example of these remarkable and lamentably unpreserved locomotives in the year 2025.

They say that 2025 was “the year of the frame” because the frame was finally put together. We might say that for the PRR Trust, this was the year of welding. Back when the Baldwin and Altoona works were turning out the originals, the frames for steam locomotives were cast, not welded. There might not be anywhere on Earth to get a 64′ long (19.5 m), 71,000 lbs steel casting made these days. Building it up with welded steel might not be perfectly accurate, but it’s the sort of hack that’s needed to keep the project moving.

The cylinders, too, would have been bored-out castings back the day. Getting the four (it’s a duplex, remember) assemblies cast as one piece didn’t prove practical, so T1 #5550 will have welded cylinders as well. Given modern welding, we expect no problem with holding steam pressure. The parts are mostly machined and will be welded-together next year.

The giant wheels of the locomotive have been cast, but need to be machined. It’s not impossible to believe that locomotive #5550 will be on its frame, on its wheels, in 2026. The boiler is already done and the injectors to get water into it have been reinvented, which can perhaps be considered another hack.

Right now, if donations continue to trickle in at the current rate– and prices don’t rise any faster than they have been– the Trust hopes to have the locomotive steaming in 2030. She’s now 59.8% complete. That’s up from 40% when we last checked in, back in 2022, which is great progress considering this is a volunteer-driven, crowd-funded effort.

If you don’t have the skills or geographical location to volunteer with this build, but we’ve piqued your love of steam, perhaps you could 3D print an engine to scratch the itch.

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Hackaday Links: September 28, 2025

September 28, 2025 by 14 Comments

In today’s “News from the Dystopia” segment, we have a story about fighting retail theft with drones. It centers on Flock Safety, a company that provides surveillance technologies, including UAVs, license plate readers, and gunshot location systems, to law enforcement agencies. Their flagship Aerodome product is a rooftop-mounted dock for a UAV that gets dispatched to a call for service and acts as an eye-in-the-sky until units can arrive on scene. Neat idea and all, and while we can see the utility of such a system in a first responder situation, the company is starting to market a similar system to retailers and other private sector industries as a way to contain costs. The retail use case, which the story stresses has not been deployed yet, would be to launch a drone upon a store’s Asset Protection team noticing someone shoplifting. Flock would then remotely pilot the drone, following the alleged thief back to their lair or hideout and coordinating with law enforcement, who then sweep in to make an arrest.

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Remembering ISDN

January 15, 2024 by 89 Comments

We are definitely spoiled these days in terms of Internet access. In much of the world gigabit speeds are common and even cheap plans are likely to be measured in 100s of megabits. But there was a time not long ago when a fast modem received at 56 kilobits per second. If you couldn’t justify a dedicated T1 line and you had a lot of money, you might have thought about ISDN – the Integrated Services Digital Network. [Tedium] has a great retrospective now that the UK has decided to sunset ISDN in 2025. ISDN started in the UK in the mid-1980s.

ISDN offered two 64-kilobit channels that could be bonded to reach 128 kilobits. There was also a slower third channel for commands and signaling (although you could use it for data, too, using an X.25-like protocol). If you wanted phone service, your voice was on one 64K channel and the data on the other. No need to tie up your phone just to get online. Voice was digitized at 8 kHz with 8 bits of G.711 encoding.

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Dissecting A T1 Line

June 1, 2022 by 13 Comments

When it comes to internet connections, here in 2022 so many of us have it easy. Our ISP provides us with a fibre, cable, or DSL line, and we just plug in and go. It’s become ubiquitous to the extent that many customers no longer use the analogue phone line that’s so often part of the package. But before there was easy access to DSL there were leased lines, and it’s one of these that [Old VCR] is dissecting. The line in question is a T1 connection good for 1.536 Mbit/s and installed at great cost in the days before his cable provider offered reliable service, but over a decade later is now surplus to requirements. The ISP didn’t ask for their router back, so what else to do but give it the hacking treatment?

In a lengthy blog post, he takes us through the details of what a T1 line is and how it’s installed using two copper lines, before diving into the router itself. It’s an obsolete Samsung device, and as he examined the chips he found not the MIPS or ARM processors we’d expect from domestic gear of the period, but a PowerPC SoC from Freescale. Connecting to the serial port reveals it as running SNOS, or Samsung Network Operating System from an SD card, and some experimentation finds a default password reset procedure through the bootloader commands. The rest of the piece is dedicated to exploring this OS.

There was a time before the advent of the Raspberry Pi and similar cheap Linux-capable boards, that hacking a router was the way to get a cheap embedded Linux system, but now it’s much more done to liberate a router from the clutches of manufacturer and telco. Still, it’s very much still part of the common fare here at Hackaday.