The gradients in railways are important, since they may kill the efficiency.
One of the most critical factors determining the maximum gross weight of a full train is the max gradient all along the route. This gradient, together with the traction power of loco and the strength of couplings of wagons, determine the maximum gross weight of a train.
As an example, a loco going from Gebze to Eskisehir can run with 2500 gross tonnes on big part of the route, but can only run with 750 tonnes because of the Bilecik-Karakoy section. Thus the loco should run under capacity on other sections of the route.
A solution for this problem is running additional loco on that part. TCDD is using this solution in some critical points. But even this means using one loco and staff very inefficiently most of the time.
Below map shows the top 20 steepest gradients in Turkey killing the total efficiency:
| No | Railway Section | Exact Point | Gross To* |
| 1 | Samsun-Sivas | Demirciköy-Ladik | 725 |
| 2 | Gebze-Eskişehir | Bilecik-Karaköy | 750 |
| 3 | Bandırma-Alsancak | Bandırma-Kuşcenneti | 880 |
| 4 | Alsancak-Afyon | Alaşehir-Nohutova | 880 |
| 5 | Alsancak-Afyon | Oturak-Yıldırımkemal | 880 |
| 6 | Yolçatı-Kurtalan | Uluova-Kürk | 895 |
| 7 | Kurtalan-Yolçatı | Maden-409.km | 910 |
| 8 | Yenice-Konya | Yenice-Ulukışla | 910 |
| 9 | İskenderun-Fevzipaşa | Mamure-501.km | 930 |
| 10 | Konya-Yenice | Çakmak-Ulukışla | 930 |
| 11 | Kırıkkale-Ankara | Irmak-Lalabel | 1005 |
| 12 | Fevzipaşa-İskenderun | Fevzipaşa-503.km | 1010 |
| 13 | Alsancak-Dinar-Afyon | Selçuk-Çamlık | 1040 |
| 14 | Alsancak-Dinar-Afyon | Dinar-388.km | 1065 |
| 15 | Goncalı-Denizli | 1065 | |
| 16 | Irmak-Zonguldak | Gümüşdöven-142.km | 1070 |
| 17 | Erzurum-Kars | Horasan-Sarıkamış | 1075 |
| 18 | Alsancak-Bandırma | Soma-Yeniköy | 1075 |
| 19 | Bandırma-Alsancak | Balıkesir-Soma | 1075 |
| 20 | Zonguldak-Irmak | Karabük-İsmetpaşa | 1090 |
* Max gross ton for a DE33000 loco with coupling pulling capacity of 100 to
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Cover Photo: Jeff Hawken ©
