Based on sprites by .
As the 1930s loomed, the Pennsylvania railroad realized that things were going to have to change if they wanted its locomotive fleet to be strong enough to handle the traffic. Their solution was to hire Italian engineer Augusto Lombardi. Who was immediately commissioned to analyze the current steam engine fleet, and declare what the new power should be. Lombardi eventually became the Andre Chapelon of North America. Creating engines that were efficient, powerful, and fast. Though some never got past the prototypes due to war or other factors. They started out as simply pre-existing PRR engines with larger trailing trucks and larger fireboxes. But they soon developed into original designs with the latest steam technology. With some even bearing larger fireboxes that required 6-wheel trailing trucks.
The first generation consisted of the three steam engines listed here. These engines continued the new concept of numbering PRR engines in blocks. Which was begun with the M1 Mountain class.
Wheel arrangement: 4-6-4
Service: Express Passenger
Number built: 3
Number preserved: One
Years of production: 1928
The first in the series of the PRR's would be numerous classes of superpower types. This locomotive's design was to quit simply give the k4 pacific a larger firebox and a four wheel trailing tuck to support it. Though they did not prove to be significantly more powerful than the K4s, and were even seen working along side their predecessors. These engines were known as "Super Pacifics" due to being more or less an extended K4.
Today, one engine, 5901, survives. Having worked on The South Wind from Chicago to Louisville, she is now on display in a park at Logansport, IN.
Wheel arrangement: 2-8-4
Number built: 36
Number preserved: Two
Years of production: 1928-1934
The first 2-8-4 steam engines. These were built in the 1930s when the PRR wanted a larger engine than their L1 Mikados to haul heavier trains. Lombardi's response was to take blueprints for the I1 decapod, take away a driver and replace it with a 4-wheel trailing truck, then us the newfound space to put in a larger firebox. Then the air reservoir of the L1 mikado and the pilot of the M! mountain were placed on the front. The result was a strong, reliable fright ngine that could put its fellow freight engines, and those of other railroads, to shame easily. They were mainly referred to as "Elephants", similar to how the I1s before were called "Hippos."
Two M2s are known to exist, one being the pictured 6513, which is on display at the Railroad Museum of Pennsylvania at Strasburg. Where it is part of vast collection of PRR locomotives said museum has.
Wheel arrangement: 4-8-4
Number built: 40
Number preserved: Three
Years of production: 1929-1934
Much like the other two, this engine was based on a pre-existing PRR engine. This time, the M1 Mountain type was given a four wheel truck. Then it was given a larger firebox. The end result was the perfect PRR dual service engine. Which the PRR mainly put to work as the successors to both the K4 Pacifics and the P1 Super Pacifics. Even receiving a similar nickname to the P1s, being called the "Super Mountains." That said, the R2 proved its worth as an even better freight hauler as well. Which paved way to what would be considered by many one of the first true PRR mixed-traffic engine, and a worthy successor to the M1 Mountain.One engine, the 7021, rusted away on a siding at Indianapolis until 1986. When the society of Altoona, PA bought it to replace the 1361, which had recently been restored. Another, the prototype 7000 is on display at Coshocton, OH. Near the modernized PRR mainline. 7016 is in happy retirement on display in Pittsburgh.