Which pantograph to use?
Some countries have multiple electrification systems, thus requiring dual voltage engines with several sets of pantograph according to the catenary type.. Turkey sole electrification systems is 25 KV, however two types of electrical clearance gauge have been used.
- The early electrification of Istanbul and Ankara suburbs uses a large clearance gauge, requiring a 1,95m wide pantograph. This value is the most commonly found in Europe. Back in 1955, light 25 KV catenary was still quite new and it was thought that the lateral wind from the sea on the coastal line would push the contact wire out of the pantograph. In addition, a wide pantograph allows the contact wire stager to be increased in curves, thus saving the amount of poles needed.
- The later main lines electrification uses a small clearance gauge, requiring a 1,6 m pantograph. Indeed this small gauge induces great savings when laying catenary in Turkey's numerous tunnels, offsetting the cost of the additional poles. However, 1,6m is not a standard value; 1,45m being the common choice in many European countries.
Therefore, until the old catenary is retro fitted to the small clearance, main line engines require two pantographs: the small one and the large one! Line side signs warn the drivers when to switch from one to the other. Engines working only the Ankara and Istanbul suburbs require only the large pantograph. Engines working the Divrigi Iskenderun line require only the small pantograph.
|1450mm||AC||Switzerland, France, Great-Britain|
|1450mm||DC||Croatia, Italie, Slovenia,|
|1950mm||AC||Austria, Czechkia, Germany, Danemark, Norway, Sweden, Slovakia, Turkey|
|1950mm||DC||Belgium, Czechkia, France, Netherlands, Slovakia, Poland|
Source: Todays Railways, n°110, Feb 2005