Worldbuilding Prompt #662 - The Last Tractor

This post was inspired by a prompt in the Worldbuilding community - "Repair or Replace"

It takes place about 50 years after the events in a previous post I made - Worldbuilding Prompt #626 - The Best Currency is Life

Image created by AI in NightCafe Studio

The ancient plough-tractor hissed, wheezed, and with an alarming "Clank" that suggested something had sheared off or broken, stopped dead.

Mir-Zont climbed slowly down from the high driver's seat lugging his bag of precious ancient tools down with him. The steam engine under the cowl did nothing but tick every few seconds as metal cooled.

Opening the leather tool bag, Mir-Zont picked out a spanner almost without looking at it. He knew these tools intimately, by touch and feel. The spanner was worn and black with age, but not rust. The weekly ritual of rubbing vegetable oil into it made sure of that. A little oil and salt in the palm of the hand, worked into each steel tool, rubbed over and over until the metal felt warm to the touch and the oil was absorbed.

Unbolting the side panel over the engine, Mir-Zont peered inside. He knew this tractor's workings as well as his tools; it had been in his family's care for five generations.

Once upon a time, before the Mushroom Blight, it had been a state-of-the-art hydrogen-powered computer-controlled automated behemoth, shiny and new, working a state farm without the need for human guidance. But the Blight had burned out it's circuit boards, all the electrical components being reduced to half-melted slag.

Great-great grandma Darza had fixed it up. There was no more hydrogen, but she was a mechanical genius. She'd taken the whole turbine drive out and replaced it with an internal combustion motor. It was less efficient and noisier than hydrogen, but it had worked to scrape away irradiated topsoil and enable New Sohnt's growers to plant in the cleaner earth below. Darza has also ripped off the automated cab full of it's useless dead computers and fitted a platform with the driver's seat, steering wheel and all the other controls it needed.

Great grandpa Gar had repaired it again, when the drive shaft had stripped it's spline. No-one had the tools, knowledge or materials to make a replacement, so he had created an ingenious system of drive chains.

In his old age, Gar had been forced to repair it again. The last of the carefully husbanded gasoline had finally run out. A couple of years of running the beast on distilled ethanol had wrecked the valve seals and all the carburettor soft bits. So he'd junked the whole engine and turned it into a steam tractor. The chimney stack was something he'd crafted himself and was particularly proud of.

With ongoing careful maintenance it had lasted through the succeeding generations. Until now. Looking inside, Mir could immediately see the problem. One of the two piston rods had snapped. It had been bound to happen. Once they had been massive chromed steel rods. But when the chrome wore through, they rapidly became useless.

Replacement iron rods had been too brittle and shattered within days. But they'd found that piston rods carefully carved from straight-grained hardwood had proven remarkably durable. Each one lasted a good ten years. But when they failed, it was always sudden and unexpected. That was okay, they just carved a new one each time. But not this time. A sharp end had gone straight into the boiler, puncturing several of the delicate and irreplaceable tubes. The clank sound had been the piston, no longer controlled by the rod, turning within the cylinder and getting jammed, wrecking both in the process.

Just as Mir-Zont had seen how bad the damage was, his assistant, Harrek-Dran arrived on the scene. His face fell when he saw the damage.

"How are we going to pay the tithe now ? Si-vi-si has already said he's going to double it. It was going to be hard enough with the tractor, we'll never do it without."

"We've got no choice," Mir-Zont replied. "He's a ruler, that's why he gets three names and the rest of us only get two. He's taken to calling himself the King of All the Clans of the Alo. He's newly in charge, got to prove himself. That means he wants our crops to pay for a bigger army. Let's hope he doesn't want our sons as well."

Scratching his head, Mir-Zont studied the dead machine in silence for a minute or two. Then, squaring his shoulders to indicate he'd reached a decision, he spoke to Harrek.

"I'm going to need your help. The steam engine's beyond repair. It can go in the settlement museum next to the hydrogen one and the gasoline one. But I want it out, everything unnecessary unbolted and the whole tractor lightened as much as possible. I've got an idea....."

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Postscript; many years ago, I had a friend with a Morris Minor, back in the days when that was the kind of car people used as a cheap runaround. He bought it from some old boy, and drove it around for several years.

It was only when it blew a head gasket and he had to take the top end apart that he discovered that one of the pistons must have been holed at some point before he got the car. It had been replaced by a beautifully hand carved oak piston. With a nice layer of insulating carbon on top, it had worked fine for years.

This story is a tribute to that amazing car, and the ingenuity of human mechanics who can keep old engines going.