It was a cold evening despite the sun only just dipping beneath the mountainous horizon. The wind flowed gently across the trees, birds chittered as they settled into their nests, and even crickets were turning in for the night. This lack of sound allowed a new sound to make itself known.
Chuff-Chuff-Chuff-Chuff-Chuff-Chuff-Chuff-Chuff
A signature chuffing noise emitted from a large metal machine as it traveled down steel rails, clanking and squeaking with every wheel turn.
Two small wheels lead eight large wheels connected by a complex mechanism of rods and bearings, which lead eight more wheels with the same mechanism, trailed by two wheels exactly like those in the front. Under its cab windows was the number 4000.
Just behind this mighty steam locomotive was a large black tender. Christened on its sides were the words SOUTHERN PACIFIC. Coal was piled only to half capacity, the water even less so.
Behind the locomotive was a long, heavy train of black hopper cars, each piled high with Trona - a non-marine evaporite mineral, mined as a source of Sodium Carbonate and sometimes used in fertilizer.
With a single caboose trailing at the back, the entire train weighed close to 5000 tons.
The monster of a train slowly hauled itself up the steep and twisty track, crossing bridges and passing through tunnels before finally diverting into a yard, slowing to a stop near a small station. The train’s crew, an engineer, fireman, brakeman, and conductor, stepped off, exchanging formalities with the yardmaster before heading into the station for some food and a well-deserved rest.
The brakeman hung back, performing routine checks to make sure the train stayed in place. Testing the air brakes, locking the regulator shut, and most importantly, tying down the handbrakes. He engaged the locomotive’s independent brake alongside a number of handbrakes on the freight cars. After making sure there was plenty coal in the firebox to keep the fire running,
The plan was to leave the locomotive “running” throughout the night, allowing the crew to wake up to a train that was ready-to-go, thus saving time and money. While this wasn’t exactly routine, there were no rules against it.
This was where existing problems began to create newer, larger problems.
The locomotive, a Harriman Common Standard MC-1, was a rather poor steamer. Its articulated components tended to leak steam, thus harming performance. This, of course, was no issue when the locomotive was sitting still, using zero steam, as long as the fire was kept nice and hot.
However, since the brakeman had not been trained on steam locomotive firing and was unfamiliar with how a firebox worked, he “overfilled” the firebox with coal, incorrectly thinking it would let the fire burn hotter and last longer.
This had the opposite effect, however, as less oxygen was able to enter the firebox, which would cause the fire temperature to drop significantly. The lack of oxygen could have been rectified by engaging the “blower”, which was a device that creates a draught through the boiler that allows more oxygen to enter the firebox, increasing the fire temperature. Unfortunately, this device was not engaged.
Mere minutes after the brakeman had left, the fire temperature dropped lower and lower, decreasing in size until it ceased altogether.
With no fire to heat the water, no steam was generated, causing the boiler pressure to slowly drop as minutes ticked into hours. Theoretically, this would be trivial, only causing the crew to be rather annoyed at their lack of a ready-to-go train in the morning.
That is, until one remembers the air compressor.
This loud cylindrical object was the one and only way of supplying air to the brakes. Airbrakes, as they were called, worked via pressurized air filling up brake pipes, allowing the brakes to be released. When pressure drops, air reserves in the cars would close the piping and force the brakes on, stopping the train.
The compressor ran off of the steam from the locomotive, being more effective the higher the steam pressure was.
It also becomes less effective the lower the steam pressure is.
As the steam pressure dropped from 200PSI to 100, then to 50, even 25, the compressor wasn’t able to effectively supply air, stopping altogether when the boiler pressure was completely gone.
With no new air being supplied to the brakes, the main air reservoirs were slowly being depleted throughout the length of the train.
Worse still was that the brakeman hadn’t set enough handbrakes to hold the train, having forgotten about the slight downhill stretch of track the train was parked on.
Finally, at 12:56AM, both the air brakes and hand brakes couldn’t hold the train any longer, and it very slowly began to roll down the grade, breaking a track switch and forcing its way back onto the main line.
The only person who had been awake to see the train was the conductor, who had woken up to the quiet whirring of brakes. He had only managed to catch a glimpse of his caboose before it disappeared from view.
The train began accelerating down the steep track, traveling faster and faster as it careened through the twists and turns of the mountain track. The locomotive’s wheels and gearing spun faster than they had ever spun before, becoming a blur as it violently shook, almost to the point of catastrophic failure.
Amazingly, despite the lack of a headlight, no fire, no way for anyone to know of the runaway, the train sailed past two other trains traveling in the opposite direction, one of them a passenger train.
The train almost looked as if it would roll all the way down the mountain and stop somewhere in a field, safe and sound, if a little worn.
This was not to be, for the train tore into a tunnel at high speed. More and more freight cars raced into the tunnel until it finally ended with the caboose, the sound of screeching metal still echoing from within. While most would expect the train to come rattling out the other end, such a sight would not come.
The train, despite its size, weight, and length, had disappeared in the tunnel, never to come out again.