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4464 'Duality'

📘 P&D Locomotive Works – Engine Catalog Excerpt
Model: P&D “Duality” Class
Type: Experimental Duplex Express Locomotive
Wheel Arrangement: 4-4-6-4
Fuel: Dual-fired (Coal & Oil)
Boiler Pressure: Classified
Production Status: Prototype / Demonstrator
Availability: 1 (Testing)

"An experimental concept refined into something operable. Dual-fired, duplex drive, and definitively P&D."

Introducing Duality, a semi-sane step in steam evolution. Developed from lessons learned during the hexaplex era and tempered by practicality, this 4-4-6-4 locomotive is dual-fired—fitted with two fireboxes (coal and oil) feeding a shared boiler. Built for resilience and flexibility, it’s capable of running off either fuel source, or both in tandem when raw power is needed.

Fitted with a semi-rigid duplex arrangement and a slightly flexible front engine to negotiate tighter turns, it balances brute force with surprising agility.

⚙️ Key Innovations:
Duplex Drive Configuration:
Split driving sets (4-4 & 6-4) reduce piston mass per axle, minimizing hammer blow while improving traction at speed.

Dual Fireboxes – One Boiler:
Coal and oil systems operate independently or in tandem. Switch fuels on the fly depending on route conditions, crew preferences, or material shortages.

Shared Draft System:
Vent-assisted combustion allows balanced airflow when both fireboxes are in use, ensuring peak thermal efficiency and sustained steam output.

Tender Integration:
Extended tender with auger-fed coal and pressurized oil lines. Designed for maximum range, maintenance access, and operator safety.

Manual Valve Control:
True to form. Engineers retain full control—no automation, no fuss, no compromises.

SMtFMM:
Two small independent motors mounted on the front pony truck, activated via rear coupling controls, completely separate from throttle—Ideal for yard adjustment, minor alignment, or cold starts.

“Where tradition meets transition.”

Whether hauling passenger stock or acting as a test-bed for future motive power, the Duality stands as a testament to ingenuity, flexibility, and the ever-burning heart of steam.

📍 For demonstration inquiries, contact your local P&D representative.


🛠️ Startup Instructions:
Fuel Supply:

Ensure the tender is filled with coal and/or oil (diesel).

Toggle the fuel pump for oil (manual valve in cab).

Engage the coal auger from the tender (separate toggle).

Fireboxes:

Use manual controls to light the coal or oil firebox.

Either firebox can operate solo, but for max performance, run both.

When both are active, vent dampers will auto-open to ensure proper airflow.

Boiler Management:

Ensure boiler water feed is on

Boiler will reach operating temperature once either firebox is sustaining heat (~115 or 150°C dependent on firebox).

Steam loop is closed, auto-cycling water unless damaged.

Watch boiler pressure & temp gauges on the cab dash.

Brakes & Operation:

Standard air brake operation.
(ENSURE THE 'BRAKE CUT IN VALVE' (on the fireman side of the cab) IS SET TO OPEN. If not the locomotive will not function. The dials will light up to confirm it's open.)

Throttle & Reverser:

Wait until boiler pressure is stable.

Set reverser and open throttle slowly—she’s responsive.

Handle with care—this isn't a light switch loco. She's got weight, and bite.

⚠️ Note: This is a manual locomotive. There is 'no' computer logic handling operations. This is by design.


(TCP is baked in! Find them here ↓)
- Discord: https://discord.gg/mAKvvuMj8J
- Micro controller collection: https://steamhost.cn/steamcommunity_com/sharedfiles/filedetails/?id=2126765606

Find Tender here!
https://steamhost.cn/steamcommunity_com/sharedfiles/filedetails/?id=3467784796