Rising Corrosives

How much punishment could an ungreased bronze impeller take before the high-pressure bearings welded themselves into slag?

Tivian shoved through the mid-morning crush of the Siphon Quarter, the heavy oilskin haversack slamming rhythmically against his bruised ribs as he calculated hydrostatic tolerances on the run. Inside the sack, wrapped against the greasy spray of the lower canals, lay the signed thirty-percent equity contract from Lady Várady, five zinc-bronze master bedrock plates, three stamped Directorate manifest slates, and his grandfather's twelve-inch diver's knife. But parchment deeds and stolen metallurgy were worthless if Szabol Kengyel turned the Lánczy slipway into an ash heap before the tide crested.

The air over the Upper Siphon reeked of scalded mutton tallow, sulphur, and wet lime. Three hundred yards to the east, iron clappers were already hammering the brass bells inside the Directorate signal towers—the rapid, three-stroke alarm warning barge masters and lightermen that the Thresher Tide had breached the outer sea-gates of the bay.

The water in the arterial cut was turning violently. The usual murky olive-green of the high canals churned into a bilious yellow froth, thickened by millions of tons of caustic bottom-silt dredged up from the subterranean fault trenches. Every surface craft caught in the lower reaches when that chemical slurry peaked would have its pitch-caulking dissolved and its cedar ribs chewed to wet pulp.

Tivian rounded the corner onto the South Lock embankment, his iron-shod work boots skidding over slime-slick cobblestones. Below the granite stairs, an old coal tender sat moored to a rusted snubbing post, its stoker frantically wrestling with a fouled hemp hawser while the yellow backwash slapped against his gunwales.

"Cast off! Cast off, you miserable bastard!" the stoker yelled down into his coal hold, his face smudged with soot and terror. "The sluice gates are dropping in ten minutes!"

Tivian leaped down the last four steps, dropped three heavy silver groschen onto the tender's forward thwart, and vaulted the gunwale before the stoker could even spin around.

"I'm taking the tow-skiff," Tivian said, drawing his heavy brass spanner and slicing the hitching lashing with a quick flick of his diver's knife.

"Hey! That's my company tender—"

"Take this coal barge into the inner lock basin and dog your sea-valves," Tivian snapped, kicking the flat-bottomed timber skiff clear of the tender's stern. "Unless you want forty barrels of caustic sludge rotting your bottom planks before sunset."

He dropped into the tow-skiff's center thwart, wrapped the frayed pull-cord of the small kerosene auxiliary engine twice around his knuckles, and hauled with everything in his back.

The two-cylinder kicker sputtered, wheezed a cloud of foul gray exhaust, and caught with a harsh, metallic rattle that vibrated through the floorboards. Tivian slammed the tiller over and cracked the choke wide.

The skiff surged into the center of the South Lock channel, cutting straight across the churning current. The rising Thresher Tide was already fighting him, a heavy, silt-thick swell that sloshed over the low gunwales in greasy yellow sheets. The drops that hit the bare skin of his forearms burned like nettles, leaving red, stinging welts where the alchemical sludge bit into his pores. He wiped the toxic spray from his cracked cheekbone with his sleeve, kept his weight pinned forward, and steered hard against the drag of the canal.

Traffic in the main thoroughfare was pure chaos. Heavy freight lighters were bumping gunwales at the lock entrances, their crews trading curses and blows with iron pike-poles as they fought for the upper basins. Tivian threw the skiff between a wallowing timber barge and an anchored grain hulk, scraping cedar paint along the barge's iron fender, his small engine screaming at top pitch as he cut through the narrowing lanes.

Two miles down-channel, where the waterway constricted into the industrial bottlenecks of the Kettle District, a greasy black pillar of smoke rose against the gray sky.

It was climbing straight out of the Lánczy yard slipway.

Tivian leaned hard over the tiller, throttling the auxiliary to its absolute mechanical limit. The piston housing was running hot enough to scorch oil, but he did not ease off. He cleared the soot-blackened masonry arches of the Iron-Gate Cut, shot through the roaring spill of the overflow weir, and rounded the final bend into the family's basin.

The sight made his teeth grind together until his jaw ached.

Three heavy, iron-plated dredge-scows were moored across the mouth of the Lánczy slipway in a tight, overlapping crescent. Their broad oak bulwarks were plated in riveted boiler scrap, boxing the yard in like the jaws of an iron vise. Heavy anchor chains were strung between the outer scows, effectively sealing the slipway ramp against any vessel trying to break out into open water.

On the catwalks of the three scows, at least a dozen cartel thugs in studded leather and grease-masks were systematically raining destruction onto the yard. They carried heavy timber cross-staves and long iron tongs, lobbing sealed clay jars of pressurized bitumen and ignited sulfur pitch straight at the workshop roof.

The roof was already catching.

A puddle of black, burning pitch crackled across the cedar shingles above the forge. On the stone apron between the tool-shed and the slipway cradles, Uncle Oszkár was wedged behind an overturned iron boiler shell. The old man was coughing violently through soot-caked goggles, his scarred hands clutching the long brass wand of an industrial blowtorch coupled to an alchemical tallow tank. Whenever a cartel skiff pushed in toward the slipway ramp to heave another pitch-bomb, Oszkár cracked the brass petcock, sending a furious five-foot spear of blue flame roaring over the yellow mud to scorch the assailants back.

"Keep your filthy hooks off the lathe bed!" Oszkár's hoarse roar carried across the din of the water. "That carriage was machined on true lead-screws! You blister my brass and I'll blow this entire tallow receiver down your gullets!"

A clay jar shattered against the boiler casing above his head, splashing viscous orange fire down the iron plate just inches from his shoulder.

Tivian didn't cut his speed. He angled the tow-skiff straight for the slimy mud bank below the workshop's lower apron, killed the throttle twenty feet out, and let the flat bottom ride the incoming tidal surge up onto the stone ramp.

The skiff struck the mud with a violent scrape. Tivian vaulted over the bow into the knee-deep muck, his heavy brass spanner gripped in his right fist and his knife ready in his left.

A cartel thug with a lit pitch-torch had just scrambled onto the slipway timbers, preparing to heave his brand through the open workshop window. Tivian closed the distance in three long strides, drove his shoulder into the man's ribs, and slammed the flat of the brass spanner across the side of his helmet. The thug folded into the burning mud with a breathless wheeze. Tivian kicked the dropped pitch-torch straight into the yellow tide, where the chemical sludge extinguished it with a loud hiss.

"Uncle!" Tivian shouted, grabbing the old man's leather apron and hauling him back under the deep granite archway of the tool-shed. "Shut the tallow valve! Don't let them burn the main cradle timbers!"

Oszkár dropped the torch wand, hacking up thick gray phlegm as he pushed his goggles onto his forehead. His blind eye stared white and milky beneath the soot, while his good eye locked onto Tivian with fierce relief.

"You took your sweet time, boy!" Oszkár coughed, rubbing a grease-blackened sleeve across his mouth. "Szabol brought thirty men and three armored scows from the Lower Reach. He's got iron chains slung across the channel mouth—he means to pin us inside the cut until the Thresher Tide peaks and rots every hull timber we own down to the copper rivets!"

"He's not pinning anything," Tivian said, shaking stinging canal spray from his eyes. He turned toward the covered slipway cradle.

Resting on the greased timber skids was the family's shallow-draft pump-skiff, the Csuka. Mounted squarely over its midship keel was the heavy Mark IV Silt-Engine Tivian had stripped from Szabol's crew in the Lower Sluice two days earlier. Its brass-jacketed boiler was unlit, but its dual alchemical receivers were already plumbed into the twin high-pressure impellers beneath the stern.

"Is the primary accumulator charged?" Tivian demanded.

"Four hundred and twenty pounds on the master dial," Oszkár replied, pointing to the copper piping running along the cradle wall. "I charged the tanks off the workshop steam boiler before their pitch-bombs took out my chimney draft. But the bypass regulator is set for harbor patrol speed! If you dump that much live head into the drive without venting, you'll shear the impeller keys right off the shafts!"

"We aren't patrolling," Tivian said, pulling off his oilskin haversack and shoving it into the watertight copper coffer bolted beneath the Csuka's forward decking. He dogged the brass latches down tight. "We're going to punch the center dredge-scow clean through its midship ribs."

Oszkár stared at him, his mouth agape under his bristling mustache. "That scow is six-inch seasoned oak backed by three-eighths boiler plate! You'll smash the Csuka's stem into kindling!"

"Not if we hit her seam at full head while the tidal bore is lifting her keel," Tivian said. "I know that scow. It's the Bölény—built at the Karpathy yards four winters back. They used soft green spruce for the cross-frames and lead-caulking on the midship bulkhead. Hit that joint with forty horsepower on a rising wave, and the whole hull will buckle like an empty crate."