Madrid, Zaragoza & Alicante 4-8-2 Locomotives in Spain

Class 1701/241-2001 (Locobase 3392)

Data from [] and [] (28 April 2003).

Reder (1974) describes these as the MZA's most successful engines "with their effective boilers and simple construction ..." They differed in appearance from the Norte's compound Mountains, which appeared the same year, in having only one sand dome (behind the steam dome) and the main rod driving the third axle. The first 75 used the Lentz valve gear, the last 20 Dabeg poppet valve gear. Over a line profile between Arcos and Torralba that included six miles of 1.67% grade and continuous 0.75% grade, the trial engine pulled a 535-ton load at 26 mph (41.9 km/h).

The latter shows five subclasses that differed in total engine weights from 227,076 lb for the first group of 25 up to 235,762 lb for the last ten. The second batch of 40 had the lowest adhesion weight at 140,765 lb while the last ten were again the heaviest at 146,034 lb.

Pere Comas, whose Paleontologia Vaporosa posts on the family tree of Spanish 4-8-0s are referenced in Locobase 3382, says that the answer to the power shortage afflicting MZA expresses as they struggled up the better than 1% grades they encountered was the species "Montagna Regina" that entered service in 1927. The last ten he dubs "Montagna Regina Otorrinus" to recognize a subspecies that came with "Elephant Ear" smoke deflectors flanking the smokebox. These locomotives were the exclusive power of the MZA express trains and the species became known as "La Reina de MZA" (The Queen of the MZA).

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Class 1801/241-2101 (Locobase 3393)

Data from [], the web site of the Spanish National Railway and [] The latter reproduces the diagrama with all weights and dimensions as well as a photograph.

Photographs show these express locomotives to have resembled the British Merchant Navy class Pacific in their air-smoothing casings, but the MZA engines were smaller and smaller drivers.

Pere Comas, whose Paleontologia Vaporosa posts on the family tree of Spanish 4-8-0s are referenced in Locobase 3382, identifies this elaboration of the earlier species "Montagna Regina" (Locobase 3392) as "Montagna Velocipedus". The principal difference was the highly pressed boiler, which was intended to generate more power within the same dimensions. Comas notes that the Civil War, the war in Europe, and postwar (i.e., 1939 and later) isolation threw up barriers to MTM's acquisition of the appropriate steel and special lubricants. Nevertheless, the company delivered the ten locomotives in 1939 and, he adds, the bad omens that had weighed on the project from its birth were fulfilled.