PKP classification system

PKP classification system is a system of assigning letters and numbers to series and individual locomotives used by the PKP - Polish national railroad operator.
The system was introduced for the steam stock by the Ministry of Railways on 3 November 1922, shortly after Poland regained her independence when the Polish railroads inherited a variety of German, Austrian and Russian steam locomotives, each with its own type convention. It was put into use in 1923–1926 years. The adopted solution allows telling the locomotive type, wheel arrangement, origin and some other information from the type designation. After World War II a similar system was also adapted for diesel and electric locomotives.

Electric and diesel locomotives

In the case of electric and diesel locomotives, and multiple units, a designation consists of two capital letters and two digits, without a space between letters and digits. The first letter E or S indicates a kind of traction, the second letter indicates a locomotive purpose. Digits mark subsequent classes, and their ranges also carry additional information on construction features. Some railcar classes have three digits.

First letter

E - electric locomotive
S - diesel locomotive

Second letter

Locomotives

P - passenger locomotive
T - freight locomotive
U - mixed-traffic locomotive
M - shunting locomotive

Electric multiple units

W - for high platforms
N - for both high and low platforms
D - for long distance traffic
R - for suburban traffic

Diesel railcars and multiple units

D - for long-distance trafficN - for suburban trafficR - special purpose A - railbus

Numbers

Electric locomotives

01-'14 - four axles, Bo-Bo, direct current, 3 kV
15-19 - four axles, Bo-Bo, alternating current
20-34 - six axles, Co-Co, direct current, 3 kV
35-39 - six axles, Co-Co, alternating current
40-49 - other types

In the case of electric and diesel locomotives consisting of two cars, the letters A' and B were added after the serial number for each car but the number is still the same for both the cars or after important modernisation.

Electric multiple units

51–'64 – three-car set, 3 kV DC
65–69 – three-car set, AC
70–74 – four-car set, 3 kV DC
75–79 – four-car set, AC
80–89 – single electric car, any voltage or type of current
90–93 – two car sets, 800 V DC
94–99 – other

Every car in a multiple unit is further designated by its own suffix:

s' – motor car
d – trailer car without a driver's cab
r – trailer car with a driver's cab

If there is more than one car of a given designation in a unit, they are further identified with the letter 'a' or 'b'. For example, a typical 3-car EMU class EN57 consists of the following cars:ra s rb
Another 3-car EMU, class EW58, consists of the following cars:sa d sb
Example of a single car's designation: EN57-830ra.

Diesel locomotives

01–'09 – mechanical transmission, no multiple-unit control
10–14 – mechanical transmission, multiple-unit control
15–24 – hydraulic transmission, no multiple-unit control
25–29 – hydraulic transmission, multiple-unit control
30–39 – electric transmission, no multiple-unit control
40–49' – electric transmission, multiple-unit control

Diesel railcars and multiple units

51–'59 – mechanical transmission, no multiple-unit control60–69 – mechanical transmission, multiple-unit control70–79 – hydraulic or hydro-mechanical transmission, no multiple-unit control80–89 – hydraulic transmission, multiple-unit control90–94 – electric transmission, no multiple-unit control95–99' – electric transmission, multiple-unit control

Steam locomotives

Image:Ty43 17 locomotive plate.jpg|thumb|200px|right|An example of a Ty43 class locomotive designation: T stands for freight locomotive and y stands for 2-10-0 wheel set. 43 describes Polish production, 1943 year of design approval.
Designations of standard gauge PKP steam locomotives consist of two letters and a number written directly behind the letters. Designations of narrow gauge locomotives follow other rules.

First letter

The upper case letter means:

P - fast train locomotive
O - mixed/stopping train traffic
T - freight locomotive

Last letter

Last letter indicates the wheel arrangement, in increasing order of the number of driving axles.

a - one driving axle, any number of unpowered axles
b - 0-4-0
c - 2-4-0 or 0-4-2
d - 4-4-0 or 0-4-4
e - 2-4-2
f - 4-4-2 or 2-4-4
g - two driving axles, more than three unpowered axles,
h - 0-6-0
i - 2-6-0 or 0-6-2
k - 4-6-0 or 0-6-4
l - 2-6-2
m - 4-6-2
n - 2-6-4
o - three driving axles, more than three unpowered axles
p - 0-8-0
r - 2-8-0 or 0-8-2
s - 4-8-0 or 0-8-4
t - 2-8-2
u - four driving axles, more than two unpowered axles
w - 0-10-0
y - 2-10-0
z - five driving axles, more than one unpowered axle

Middle letter

In the case of tank engines, the letters designating the type of engine and the wheel arrangement are separated by a K. Thus TKt48 is a 2-8-2T tank locomotive of Polish design introduced in 1948.

Number

1-10 - German or Prussian origin steam engine
11-19 - Austrian origin steam engine
20-99 - Polish-ordered steam engine, number stood for the last two digits of the year in which the type was approved for production
100 - different atypical stock, acquired after 1945, including former private and industry locomotives
101-199 - Other foreign steam engine, acquired by PKP between 1918 and 1939
201-299 - Other foreign production steam engine, acquired by PKP after 1945

Serial numbers

Following the letters and numbers described above, the serial number of each individual locomotive is stated. This consists of several digits, separated from the type designation characters by a dash.

Tenders

First number

First number of tender classification described water capacity in cubic meters made even upwards.

Letter

Letter described the number of axles, i.e.:
*B - two axles
*C - three axles
*D - four axles

Second number

This referred to the year of construction, so number 23 means the construction was approved in 1923. Numbers 1 to 10 meant Prussian or German origin, 11 to 19 - Austrian origin, above 101 - other foreign origin.

An example

A tender numbered 22D23 can carry up to 22 m³ of water, has four axles, and its construction was approved in 1923.