The PRR M1 steam locomotive is a 2-4-1 steam locomotive (in the American 4-8-2 Mountain Record) built in the United States by order of the Pennsylvania Railroad company at the Lima Locomotive Works , Altoona Works and Baldwin Locomotive Works factories.
| PRR M1 | |
|---|---|
 | |
| Production | |
| Country of construction | USA |
| Factory | Lima Locomotive Works Altoona works Baldwin Locomotive Works |
| Years built | 1923 - |
| Total built | 301 |
| Technical details | |
| Axial formula | 2-4-1 |
| The diameter of the driving wheels | 1829 |
| Track width | 1435 mm |
| Official weight of the locomotive | 174.6 |
| Boiler steam pressure | 17.6 atm |
| Number of cylinders | 2 |
| Bore | 686 |
| Piston stroke | 762 |
| Exploitation | |
| A country | USA |
| Road | Pennsylvania Railroad |
An experienced steam locomotive was built in 1923, the serial production of steam locomotives began in 1926 . Total released 301 locomotive. Track width 1435 mm.
The steam locomotives of the Pennsylvania railroad type M1 were designed for heavy mining. Driving on these locomotives were four wheelsets . Two wheel pairs, located under a rather large furnace of a locomotive, reduced the axial load from a heavy locomotive.
Despite the fact that locomotives were produced for both passenger and freight traffic, mostly locomotives were used in freight traffic with accelerated freight trains .
Many drivers of the Pennsylvania Road considered this locomotive to be the best among those they met.
The first steam locomotive was built at the PRR factory in the city of Altoona . After three years of intense testing in train work and static tests, positive results were obtained. The management of the company decided to order another 200 steam locomotives of this series according to its drawings in the Baldwin Locomotive Works (1975 units) and Lima Locomotive Works (25 units) plants. Upon entering the road, these locomotives received numbers from 6800 to 6999.
In 1930, the road ordered another 100 locomotives of this series. At this time, the locomotives received several changes in the design, so the index a (PRR M1a) also appeared in the title. A steam water heater was installed on the steam locomotives. Instead of one steam-air pump , two were installed. Increased capacity tenders .
Since the PRR M1a steam locomotives were designed to work with both passenger and freight trains, they were decorated with golden leaves on the driver’s cab and tender. However, in terms of their characteristics, they were more suitable for cargo handling, moreover, the Pennsylvania Railroad was electrified and a large number of PRR K4s steam locomotives were released .
Like many PRR locomotives, the Mölper M1a and Belper firebox was used with a flat ceiling. The expanded chamber of the firebox allowed the complete combustion of combustible gases. The boiler of the engine was designed for a pressure of 17.6 atm (1.72 MPa ). Subsequently, on 38 locomotives, the boiler pressure was increased to 19 atm (1.86 MPa).
The distinguishing feature of the locomotive, by which it could be distinguished from the others, was a large air tank mounted above the broomstick .
The tender operated with this locomotive is equipped with a ladle, with which he could draw water from the water trough on the go.
When diesel ( Dieselisation ) railways steam locomotives PRR M1 still remained in operation. Yielding to diesel locomotives in speed, they won in power and drove heavy freight trains. Many locomotives were operated until the middle of 1957 , when PRR finally decommissioned all locomotives.
One locomotive bearing the number 6755 is preserved for the historical PRR collection at the Museum of Northumberland .