The Railroad Museum at Ardenwood

SPCRR No. 581

Item

Dublin Core

Title

SPCRR No. 581

Subject

SPCRR No. 581

Format

Locomotive

Locomotive Item Type Metadata

Road Number

581

Locomotive Model or Class

CN6663 10/1968 36" HSG B 5 ton D/H; 5-Ton Diesel-Hydraulic locomotive with high cab

Status

Operable

Builder / Manufacturer

Plymouth Locomotive Works, Plymouth, OH

Build Date

10/1968

Historical Road Numbers

US ARMY #581
    1968
US ARMY #588
    19XX
Olin Corp #OB-588
    19XX

Weight

5 ton

Wheel Arrangement

0-4-0 / "B"

Fuel Type(s)

Gas (Original), Diesel (2018-)

Date Acquired

1999/2004

Restoration History

Rebuilt in 20XX by SPCRR
Renumbered to 581 in 20XX

Ownership / Custodial History

US ARMY #581 > #C0268 Badger Ammunition Plant, Baraboo WI
Olin Corp #OB-588, Badger Ordnance Works, Baraboo WI
Sold to Brook Locomotive Works, Georgetown CA
Sold to SPCRR, 2004, Renumbered #1 then #581

Online Description

This 5-ton industrial switching locomotive was manufactured by Plymouth Locomotive Works with a gasoline engine and hydraulic transmission. It originally served the U.S. Army's Badger Ammunition Plant as #581, later renumbered to #588 [reason for renumbering unknown]. The Badger Army Ammunition Plant, located in Wisconsin, was a major U.S. military munitions manufacturing facility that maintained an extensive internal railroad for moving materials between production buildings.

Plant operations were suspended in 1977 and the facility permanently closed in 1997. The locomotive was sold at government surplus auction to a group of private buyers in 19*X* and stored in Long Beach, California from 2*0*X* to 201*X*. SPCRR purchased the locomotive in 1999 with the condition that it be named ""Katie"" after the daughter of one of the sellers - a requirement that was incorporated into the sale agreement and has been honored throughout SPCRR ownership.

The locomotive entered service as SPCRR #1 "Katie" and became the museum's primary motive power. Initial service revealed the gasoline engine's age, limitations, and higher operating costs. After several years of service, the yellow paint showed significant deterioration. A "guerrilla" spray paint job using rust red primer was applied and the locomotive maintained its #1 designation. By 2016, this temporary paint job had badly deteriorated.

During winter 2016, SPCRR volunteers undertook comprehensive refurbishment: the locomotive was stripped to bare metal, properly painted, and lettered as SPCRR #1. During winter 2018, a major mechanical upgrade replaced the gasoline engine with a diesel engine, and air brake controls and pump were added to meet air braking requirements for passenger train operations - a significant investment that greatly improved operational capabilities and safety.

In 2020, the locomotive was renumbered to SPCRR #581 "Katie," returning it to one of its original Badger Ammunition Plant numbers and providing historical continuity. It has served as the primary SPCRR motive power from 2015 to 2025, replacing our original horse-drawn service, and has accumulated thousands of hours in revenue service.

Collection

Citation

Plymouth, “SPCRR No. 581,” The Railroad Museum at Ardenwood, accessed October 1, 2026, http://museum.spcrr.org/items/show/9.