They featured a German prime mover with a hydraulic transmission, an auxiliary diesel and generator for on-train power, and two externally energized electric traction motors.

The RP-210's twelve-cylinder 1,000 horsepower (750 kW) German Maybach MD-655 main diesel engine was mounted rigidly to (and pivoted with) the Mekydro hydraulic transmission (renamed Mechydro by Baldwin) on the locomotive's front truck.

As the track speed there is limited to 35 mph (56 km/h) or less, the small traction motors at the front and rear of the lightweight train (a combined 600 hp (450 kW)) were considered adequate.

To meet the need for dual-powered operation, the New Haven's Bronx-based Van Nest electrical shops initially fitted the Baldwin units with one third-rail contact-shoe per side, bolted to a reinforced journal box bracket on the lead axle of the locomotive's rear truck.

The Van Nest engineers and mechanics therefore scrambled to design a full-length support bracket for the RP-210's lead truck and attached a rather unconventional contact-shoe assembly to it.

[3] On January 7, the Dan'l Webster left Boston with New Haven president, George Alpert, and about 225 newsmen, promoters, politicians, and railroad managers aboard for the press-run.

The damaged contact scraped along the energized rail, creating a ground arc of electricity that set the locomotive's truck ablaze and began to melt away the aluminum side-skirting above it.

Minus the rear RP-210 locomotive and the last coach (which could not be detached, due to fire damage), the rest of the Dan'l Webster eventually proceeded on to Grand Central in New York City.

While being towed back to Van Nest shops by a switcher engine, the lightweight coach attached to the damaged locomotive derailed near Pelham station in Westchester County, resulting in an additional four-hour delay for evening commuters.

A larger and more traditional mechanism, which the New Haven had regularly fastened to the journal boxes of their electric locomotives, was modified to fit the front and rear trucks.

All New Haven and New York Central electric locomotives operating into the terminal were equipped with a small spring-tension roof-pantograph, mounted on a telescoping pole which extended to the overhead power supply.

Road mechanics were unfamiliar with the foreign prime mover and reported having to forage for metric hardware components at local Volkswagen dealerships.

[1] At the New York Central's Collinwood Shops in Cleveland, where the RP-210 and its train became frequent visitors, maintenance crews first dubbed the new equipment, Mighty Mouse, for its relatively diminutive stature, and the whiskers-and-mouth effect suggested by the logo on the locomotive's shark-nose front.

[6] The New York Central's Ohio Xplorer train and its RP-210 diesel sat inactive until June 1963, when they were sold to Jones Tours, a subsidiary of the Pickens Railway, a Class-3 short-line in South Carolina, for use in passenger excursion service.

The train was pulled by a locomotive of its Class-1 hosts (on Seaboard, usually an EMD GP9), with in-train electricity provided by the auxiliary diesel-powered generator on board the Baldwin unit.

[2] Alan R. Cripe, who played a major role in the engineering development of Train-X under the auspices of the Chesapeake and Ohio Railway in the early 1950s, applied for inventor's patents covering some of the technology used in its design (January 10, 1956).