The Heart of the Restoration: If the boiler is the heart of a steam engine, then the firebox is its furnace, where coal turns water into the power of steam. For No. 12, that means a complete firebox rebuild.
Breaking Down The Boiler
With the outer jacket off, these internal parts will be removed:
188 flues (tubes that carry hot gases through the boiler)
Flue sheets
The dry pipe, which channels steam to the cylinders
Around 750 staybolts, which secure the firebox to the boiler shell under pressure
The staybolts are being machined off-site and will be installed with help from our team when the firebox rebuild begins.
Why Rebuild the Firebox?
Over time, intense heat and pressure fatigue the firebox walls. Rebuilding involves custom-fabricated steel plates, precise welding, and regulatory approvals, since the entire assembly must withstand more than 180 psi safely.
Our Role:
Tweetsie Railroad’s crew will assist boiler construction experts with staybolt installation, and will handle repairs under the engine, plus work on the smokebox front, timed so everything can be steam-tested together.