In 1933, the total cost for this improvised mortar setup would be approximately $45.00 to $50.00 USD (roughly $1,100 today). The bulk of the expense lies in the $30.00 high-pressure steel flask and the $10.00 industrial steel pipe used as the barrel. The remaining $5.00 to $10.00 would cover the 2 kg of methane gas, a large wooden crate of black powder for propellant, and basic wiring for an electrical igniter. Compared to a standard 1930s artillery piece, which cost thousands of dollars, this system provided the destructive power of a heavy siege shell for the price of a high-end business suit, making it an exceptionally cost-effective option for clandestine or irregular forces. Operation of the device is a methodical process of manual labor and basic physics. First, the 2-meter steel pipe is buried at a 45-degree angle against a heavy timber baseplate to absorb the massive recoil. A canvas bag containing roughly 1 kg of black powder is dropped to the bottom of the barrel, connected to a long wire lead. To ensure a powerful launch, the 92 kg methane tank is wrapped in thick, oily rags or grease-soaked burlap; this acts as a "sabot," creating a tight airtight seal against the inner walls of the pipe so no pressure escapes. Once the tank is slid into the muzzle, the operator retreats to a safe distance and connects the wires to a 6-volt battery. The resulting explosion of the black powder shoves the lubricated tank out of the barrel with a muffled "thump," hurtling the 200-pound projectile in a high arc toward the target 40 meters away. SOLDIER’S HANDBOOK: 10-INCH PROJECTOR OPERATIONS (1929) Standard Operating Procedure for Sector 4 Defensive Line 1. The Emplacement (The "Dig") Every 50-meter "Block" requires 40 individual pits. • The Angle: Use the provided timber triangle to ensure the pipe is at a 45-degree northern incline. • The Bedding: Do not just throw dirt. As shown in the training photo, the base must be braced against a double-layer of railway ties. Use the shovel to pack clay and sandbags tightly around the lower third of the pipe. If the earth is soft, the recoil will sink the pipe, and your shot will fall short. 2. The "Oily Sabot" Loading Procedure Loading the 92 kg (200 lb) flask is a two-man job. • Step A: Drop the pitch-sealed 1.5 kg black powder bag to the bottom of the barrel. Ensure the electrical lead wires hang out of the muzzle. • Step B: Wrap the methane flask in the standard grease-soaked burlap. The wrap must be thick enough that you have to "shove" the tank into the muzzle. If it slides in too easily, the range will be halved. • Step C: Slide the tank down until it "thumps" at the bottom. Do not drop it—a 250-bar flask must be handled with the respect of a sleeping giant. 3. The "Soot-Scrub" (In-Battle Maintenance) Between the first, second, and third shots, the barrel must be cleared of black powder residue. • The Swab: Dip the 10-inch wire brush into the kerosene bucket. • The Action: Pump the brush three times to the bottom. This dissolves the "soot-glue" so the next tank doesn't jam. • Warning: The kneeling soldier (the "Shoveler") must watch for sparks. If the barrel is smoking, wait ten seconds before pouring kerosene, or you risk a "flash-fire" in your face. 4. The Firing Chain (The "Exploder") The wooden crate at the end of the line is the only thing that matters. • Connection: Use the paraffin-dipped copper leads. Connect all 40 pipes in a series. • The Test: Before firing, use the needle-gauge to check for a "Closed Circuit." If the needle doesn't move, a wire has been cut by shrapnel or dissolved by kerosene. • The Launch: When the command "VALVE UP" is given, throw the knife-switch or depress the plunger. Retreat three meters and cover your ears. POST-BATTLE RECOVERY After the third volley, the barrels are to be left to cool for one hour. Do not attempt to reload a hot pipe. The methane flasks that did not launch (Misfires) are to be treated as live bombs. They must be extracted by the "Hook-and-Line" team only after the electrical leads have been cut. Case Finalized. You have the science, the cost, the map, and the training. You are ready to present the 1929 Methane Defense to your host.
STRATEGIC INTELLIGENCE DOSSIER: PROJECT "VAPOR HAMMER" (1929) Classification: TOP SECRET / EYES ONLY Subject: Implementation of the Methane-Charged Projector Defensive Doctrine Date of Filing: October 12, 1929 I. THE SCIENTIFIC FOUNDATION (RESEARCH & PHYSICS) Between 1927 and 1929, the Department of Ballistics successfully transitioned from laboratory theory to the "Vapor Hammer"doctrine. Abandoning the massive 42 kg "Town Killer" industrial tanks due to logistical instability, research settled on the 2 kg methane flask as the optimal tactical unit. The physics rely on Fuel-Air Explosive (FAE)dynamics. Unlike traditional TNT, which carries its own oxidizer, methane utilizes atmospheric oxygen. When the 250-bar forged steel flask catastrophically ruptures upon impact, it creates a 5-meter wide aerosol cloud that, upon ignition, generates a 1 megajoule blast(equivalent to 125 Mk 2 grenades). The result is a high-brisance shockwave that crushes reinforced bunkers and a thermal fireball that incinerates open trenches. II. THE HARDWARE & BATTLEFIELD REALITY The system utilized repurposed WWI Livens Projector technology. The "barrel" is a 10-inch diameter, extra-heavy-wall industrial water pipe, buried at a 45-degree angle to utilize the earth as a massive recoil absorber. • The Sabot: As seen in Figure A (Historical Record), the 92 kg projectile is wrapped in grease-soaked burlap. This creates a pneumatic seal, ensuring that the 0.1 kg to 1.5 kg black powder lifting charge effectively "lobs" the tank to ranges of 40m to 1km. • Maintenance: Battlefield operations are grueling. To fire the secondary and tertiary rounds, crews must scrub the "soot-glue" from the barrel using a 10-inch wire brush and kerosene. The electrical firing boxes—bitumen-lined wooden crates—are kept meters away from the "soot-rain" to prevent short-circuiting the 6V ignition harness. III. LOGISTICAL SCALE & INDUSTRIAL COST (20 KM FRONT) To fortify a 20 km (12.4 mile) sector, the nation would deploy a density of 40 projectors every 50 meters. This ensures a total overlapping "kill zone" that no 1929 infantry force could breach. • The Arsenal: 16,000 barrels and 48,000 methane flasks (3 shots per barrel). • The Weight: Over 6,000 metric tons of equipment, requiring a dedicated 150-car freight train or a fleet of 2,000 heavy 3-ton trucks. • The Fuel: Sourced from 2,300 tons of high-grade coal, processed through urban gasification plants—making the weapon essentially a "distilled" form of the nation’s primary energy source. • Financial Advantage: At $40.00 USD per shot (inclusive of the reusable 250-bar flask and buried pipe), the system provides the fire-density of a 240mm siege howitzer for 1/8th the cost of traditional high-explosive artillery. IV. THE TACTICAL "GLASS JAW" (WEAKNESSES) Despite the overwhelming firepower, the "Vapor Hammer" possesses significant vulnerabilities. Being a static defense, once the first "thump" is heard, the battery is susceptible to counter-battery sound ranging. Furthermore, the 16,000 buried high-pressure tanks create a chain-reaction risk; a single lucky hit from an enemy 155mm gun could trigger a series of BLEVE (Boiling Liquid Expanding Vapor) explosions that would vaporize kilometers of friendly trenches. V. EXECUTIVE SUMMARY FOR THE HOST "Host, in the year 1929, the Methane Projector is the ultimate industrial equalizer. It allows a nation with a coal surplus but limited nitrate production to create a 20-kilometer wall of fire. By marrying the raw pressure of the chemical industry with the crude power of the trench mortar, we have created a weapon that is invisible in the supply chain (appearing as welding supplies) but catastrophic on the battlefield. It is the most cost-effective demolition system ever devised by man." Case File Closed. Final Recommendation: Proceed with deployment in the Sector 4 Coastal Bluffs. Use the paraffin-wax terminal protocol to ensure electrical continuity in the autumn rains.