The ACE 3000 was a conceptual prototype modern 4-4-4-2 coal-burning steam locomotive which was designed in the late 1970's to early '80's by Ross Rowland, L. D. Porta, and a design team from the American Coal Enterprises company.
The project was an attempt to offer railroads the ability to use an alternative fuel to diesel. The opportunity was seized thanks to the increasing cost of diesel fuel in America due to the oil embargo and fuel crisis of the 1970s.
Although it was proposed to several railroads, no prototype was ever built. Detailed design work on all individual components was never begun. After public interest died, the project was cancelled. several factors led to this cancellation, including general disinterest, unresolved design flaws such as small driving wheels, and concerns from the EPA.
Design[]
The ACE 3000 was designed to visually resemble a diesel locomotive with the then-new "Canadian Comfort Cab," designed by the Canadian National Railroad in cooperation with EMD. It was to be equipped with an opposed duplex-drive non-articulated 4-8-2 steam locomotive chassis with 2 cylinders on either side, a double cab-forward configuration, boiler with belpaire firebox, Walschaerts valve gear, and inside coupling rods to synchronize the positions of the high-and low-pressure cylinders so they always remain opposed. It was also designed to be operationally similar to diesel locomotives by using an embedded microcomputer to control and monitor fire stoking and water usage and allow for a digital 8-notch throttle. It was to be operated by one man, the engineer (driver), who could also MU the unit with other ACE units as well as diesels and could keep itself prepared while idling.
Conventional steam locomotives, by contrast, required constant attention from a fireman to keep the steam, fire, and water all balanced to prevent a boiler explosion. Boiler Pressure was rated at 300 psi with a fire-tube arrangement and a superheater. The Drivers were a mere 54 inches. ACE's justification for this was, 'the drives were kept small so that the railroads could easily maintain them in the same facilities they maintain diesels.' Small drivers allowed for a low chassis similar to those of diesels. The locomotive was designed for a maximum speed of 70 mph, although it was made to operate most efficiently around 40-50 mph, a speed typical of most trains of the time. The Power Unit (locomotive) was also equipped with a closed condensing system which would first reduce exhausted steam to high temperature water which would then be cooled in the Support Unit (tender). This system was said to negate the difficulties caused by condensing systems on earlier locomotives. Since the exhaust was no longer available to draft the fire a turbine-driven forced induction fan was necessitated.
Maintenance[]
The small drivers were only a part of the locomotive's design effort to be very easily maintained and handled. Although the engine was to be shrouded in a cowl body which covered the boiler in a manner similar to streamlining, this cowl is easily removable and therefore should not cause hassles like other steam era designs. The cabs on both the power unit (locomotive) and support unit (tender) were to be modularized, allowing easy removal and access to all inner parts and systems.
The chassis was also designed to allow easy access to parts by keeping compact running gear and a low profile. The chassis was also equipped with built in pneumatic jack systems to eliminate the need for an overhead crane. Fueling was also greatly simplified. The Support Unit was to have 3 slots designed to fit "packets" of about 11 tons of coal each which would be loaded by crane and switched out once empty.
The coal and water supply was good for about 500 miles at maximum power, which would be roughly the equivalent of 13 hours running time. Water towers would no longer be necessary because of the Support Unit's vastly improved capacity, which is helped by the condensing apparatus.
Total water would be good for about 23 hours at optimum output. Another bonus from the improved range would be time to more thoroughly treat the water, which the design team claimed would bring the necessary boiler inspections down to one per year.
Trivia[]
- The Chessie System was interested in purchasing the locomotive, but it backed off after multiple failures of ACE to bring the locomotive to market in the time they had promised. C&O remained the longest willing customer of ACE. It went as far as running a lightly modified Chesapeake & Ohio 4-8-4 "Greenbrier" 614 to collect fresh data on steam locomotive performance.
- Since the steam is in a closed condensing system the "chuffing" sound steam locomotives are known for would be eliminated.
Sources[]
- Train Web.org - "The ACE 3000" pages 30–32, Railfan & Railroad November 1981.