While Smoulder worked on uncompelling the locomotive, Gallus set about changing the points. The heavy leaver took some effort to pull, but once it moved, the guide rail switched from leading around the curve to straight-tracked section.
Sitting on top of the tender wasn’t the most comfortable position for Spike, but he’d had worse. He considered himself lucky that he’d never shown an interest in hoarding coal. From here, he had a better view of the cab, and true to form, it looked as complicated as any mainline engine, filled with various levers and wheels of unknown functions. Surely Smoulder didn’t need all these just to make the engine start or stop?
Shuffling forward a little, he watched with great intent as she slipped back into the cab. The first thing she did was grab the lever on the right-hand side of the cab and push it all the way forward, clicking it into place on the furthest of the five notches. Next, she pulled on another lever—which Spike guessed had something to do with the breaks—before sounding the whistle.
With that, they were off, chuffing down the secondary line at a comfortable pace. The water tower wasn’t far from the station. The trees had obscured the structure around a sharp curve to the left, though he doubted he would’ve noticed if he hadn’t been looking for it.
The ride around the bend was a gentle one. How long had Smoulder been able to drive steam trains? She clearly had a lot of experience, deftly manipulating the controls with just enough force to maintain the desired speed. He couldn’t imagine working on something so complicated himself, though he supposed this was, in part, why he found the whole process so fascinating.
When Smoulder brought the locomotive to a stop, he noticed that the water tower’s swan-necked pipe was positioned just over the tender.
“All right, Spike,” Smoulder said as she pulled down the tower’s retractable ladder. “Here’s where I need a spare pair of claws. On the tender behind you, there should be a small dome with a latch on it. Pull that open, and when I swing the pipe to you, grab the rubber tube and put it inside.”
It was a simple enough task. Once the valve was opened, all Spike had to do was keep steady and let gravity do the rest. Simple as the task may have been, he’d contributed to the railway’s operations, leaving him with an odd feeling of satisfaction.
“Is there anything else I can help with?” Spike asked in anticipation.
“Well, we’re not hurting for coal right now,” Smoulder smiled softly, scratching her chin. Once upon a time, she would have looked down on such eagerness to help, but that was before Ember was crowned Dragon Lord. “So, wanna start the cab tour?”
“Heck yeah!” Expecting a lecture of Twilight proportions, Spike shuffled forward to get a better view.
Climbing onto the tender next to him, Smoulder cleared her throat. “Okay, firstly, do you know how a steam engine works?”
Spike cocked an eyebrow. “If I knew that, I wouldn’t be asking for a cab tour.”
Smoulder chuckled. “No, silly. I mean in general. You know it runs on steam, but how do you make the steam that gets everything moving?”
“Uh, I guess it’s like a hot air balloon, but with steam?”
“Y’know, that’s pretty close. The hot air comes from burning coal in the firebox. That goes through tubes to boil the water in the boiler.”
“So, kinda like a tea kettle?”
Smoulder snapped her claws. “Now you’re getting it!”
Spike rubbed the back of his head, feeling his cheeks warm. “I guess I know something after all.”
“Just don’t let it go to your head.” Smoulder winked, lightly jabbing his arm for good measure. “Anyway, once the steam is collected in the steam dome, it’s all transferred into the cylinders – those are what moves to the piston rods.”
“Oh, yeah. They’re what drives the wheels, right? The rods that kinda criss-cross each other?”
“Yup! It’s all a matter of pressure. Steam gets delivered into one side, pushing the valve forward, while the exhaust steam gets pushed out of the chimney. That’s what makes the ‘chuff’ sound you’re always hearing.”
“So, when the wheels rotate, they help to push the cylinders back in the other direction?”
“Bingo! Plus, that pressure always needs an out. The steam will go where the pressure is lowest, pushing the piston back and forth. Clever, ain’t it?”
“Wow.” Spike’s wide eyes sparkled with wonder. ‘Clever’ was putting it mildly.
“Now that that’s out of the way, I can finally show you around the cab. Did ya see the lever I pulled when the train got going?”
“The one on the right?”
“Yeah, that one. That’s the reversing rod. It sets the running gear forward or backwards.”
“Running gear, huh.” Spike mulled over the name. In addition to the piston rods, there was a cluster of smaller rods closer to the cylinders which didn’t have an obvious purpose. “Is that what’s coming out of the cylinders?”
“That’s part of it. What you’re looking at is the valve gear.”
“So, why does the reverser need so many notches? Wouldn’t you only need three?”
“I’m glad you asked.” Hopping over to the other side, Smoulder reached inside and grabbed the reverser. “Watch closely.”
Spike noticed how the valve gear moved in stages as she manipulated the rod.
“You need a lot of steam and motion to get going,” Smoulder continued. “But once you’re moving, it only takes a little push to keep forward momentum. When the reverser’s closer to neutral, the middle, it doesn’t open as much.”
“So, it saves wasting steam you don’t need!”
“Bingo. You’re catching on pretty quickly. Are you sure Twilight didn’t give you an advanced lecture?”
“Twilight hasn’t been here all week.” Spike’s expression dropped. “She left me behind… guess I’ve outlived my usefulness to her.”
Smoulder smacked her face with her palm. “Great job, Smoulder,” she muttered under her breath. “You just had to hit a sore spot.”
“It’s not your fault,” Spike replied with a dejected sigh. “I’m sorry for snapping. I just don’t wanna talk about it.”
“Hey, don’t sweat it, pal,” Smoulder placed her claw on Spike’s shoulder. “I’m the one who should apologise. I was just making a joke, but it doesn’t excuse me from hurting you.”
“No offence, but can we just move on? There are loads more train stuff I need to learn about.”
Happy to oblige, Smoulder directed Spike’s attention to the horizontal lever above the others. She explained that it was the regulator, allowing a greater or lesser flow of steam as needed to achieve speed. Next, she explained the different locomotive breaks, referencing the necessity of slowing the whole train and not just the locomotive.
She saved the most important functions for last. Gesturing to the glass water gauges, she said, “See that red line at the bottom? If you’re gonna go anywhere, then the water level needs to be above it. ‘Cause no matter how good the boiler’s insulation is, if there’s not enough water, you don’t have a locomotive anymore. You have a bomb on wheels.”
Spike grimaced. He knew enough about Equestria’s railway history to know how that analogy came about. “The water’s in the tender, right? How do you get it from there to the boiler?”
“That is where this little guy comes in handy.” Smoulder tapped on the small wheel above the reversing rod. “It’s called a steam injector. To put it simply, it uses a jet of live steam to draw water into the boiler.”
That left only one critical component to discuss. With bated breath, Spike gestured to a small lever tucked away in the bottom left-hand corner.
“That,” Smoulder continued, “is to open the drain cocks. Whenever you see the engine shoot off steam from the cylinders, that’s getting rid of any condensed water inside. Those cylinders are tough, but they aren’t tough enough to push water around.”
“Smoulder, I…” Hearing himself trail off, Spike racked his brain for anything that could express his pure fascination. He knew this would be intricate, but to understand just how many different parts there were interacting with one another was something else.
“Y’know, I didn’t expect you to be so into all this steam train stuff,” Smoulder arched her eyebrows as she smiled. “But I’ve gotta admit, it feels good to have some creature to talk to about it.”
Spike blinked. “What about Ocellus and the others? They were having a good time, weren’t they?”
“Well, yeah, but they’re just in it for the chill ride. There are other ponies who drive miniature locomotives, but they’re busy with maintenance and stuff. You’re kinda somewhere in the middle. So, thanks, Spike.”
Once again, Spike felt his cheeks go red. “I should be thanking you. I would’ve been alone all day if you hadn’t invited me.”
Smoulder hummed in thought. “Hey, I have an idea.”
“Huh?”
“Do you wanna work with these trains?”
As if Spike wasn’t already starstruck, this offer made his jaw hit the floor. He threw his arms around Smoulder in a tight hug. “Oh my gosh, yes, please! I promise you won’t regret it! I’ll work as hard as I can!”
“Well, I, uh, expect you— yeah, I guess.”
Hearing Smoulder’s flustered reply, Spike quickly let go, clasping his claws behind his back. “Oh, crud. I got carried away again, didn’t I?”
“Well, kinda, but not really? I mean, I don’t mind the mushy stuff, just… ask next time?”
“Oh, of course! Sorry, I should’ve been more considerate.” Smooth moves, Spike. Way to kill the mood. “I’d, uh, better get going. I’ve got chores to do before Twilight gets home.”
“Yeah, me too; locomotive stuff, I mean. See you tomorrow morning?”
Spike breathed a quiet sigh of relief. “What time?”
“Early. Like, seven o’clock, early. I’ve got a ton to teach you about starting up locomotives.”
Spike fought back a grimace. The last thing he needed was for Smoulder to think he was lazy, as well as impulsive. “Sure thing. I, uh, guess I’ll see you then.”
Not wanting to prolong the conversation, Spike flew off, making a b-line straight for the castle. Stupid feelings. What did you think was gonna happen? You should’ve learned from Yona. Stupid Spike, stupid, dumb excuse for a dragon, stupid…
When he was finally out of earshot, Spike released a loud, frustrated groan. This was going to be a long night.