4-4-0 Steam Locomotives in Mexico

Class J Rafael de Regil (Locobase 12436)

Data from Baldwin Locomotive Works Specification for Engines as digitized by the DeGolyer Library of Southern Methodist University Volume 23, p.76. Works numbers were 18004 in August 1900.

This appears to be a replacement for one of the earlier P & M Eight-wheelers; Locobases 11682 and 11803 show earlier engines that were built to the same specs. In other words, the P &M bought the same small 4-4-0s over a 20-year period. Pays to know your market, I guess.

The P & M was later amalgamated with other railroads into the United Railroads of Yucutan.

Class Merida (Locobase 11682)

Data from Baldwin Locomotive Works Specification for Engines, 1888, as digitized by the DeGolyer Library of Southern Methodist University Vol 14, 215. Works numbers were 9615-9616 in November 1888.

P a M was a 24-mile railroad that began construction in July 1873, but wasn't completed until 12 September 1882. It later extended a branch to Soluta 30 miles away, which accounts for the name of the second locomotive. The country was described in one account as "flat and hot".

They later wound up on the United Railways of Yucutan with numbers 9-10.

Class Progreso (Locobase 11803)

Data from Baldwin Locomotive Works Specification for Engines as digitized by the DeGolyer Library of Southern Methodist University Volume 11, p.115. Works number was 6507 in December 1882.

Specs included the requirement for this little standard-gauge little freight American-type Eight-wheeler to negotiate "curves of 100 metres radius (328 feet):.

"A.L.A."'s note, dated 3/29/83, relayed the comment offered by James Courtney in a letter datelined "12 or 15 December 1882" on the reducing valve for this little freight American-type Eight-wheeler. It wasn't " sensitive enough," ALA wrote."It closed at the right temperature, but would vary 40-50 psi (2.75-3.45 bar) before opening again." [A reducing valve managed the pressure entering the cylinders from the boiler. To say a variation of 40-60% suggested insensitivity seems understated.]

The P&M later joined the other railways in the area in the Unidos de Yucatan. At that point, the Progreso was renamed Adelaida.