| Builder: | ALCO Baldwin Locomotive Works Lima Locomotive Works |
| Whytetype: | 2-8-0 |
| Uicclass: | 1′D h2 |
SEK (Sidirodromoi Ellinikou Kratous, Hellenic State Railways) Class Θγ (or Class Thg; Theta-gamma) was a class of 2-8-0 steam locomotives ex-United States Army Transportation Corps S160 type. 27 locomotives were acquired in 1947; Θγ521–537 were coal burners, while Θγ551–560 were oil burners. In 1959, Italian Railways (Ferrovie dello Stato, FS) sold another 25, formerly Class 736, Nos 736.011/23/40/55/73/90/101/2/126/7/131/5/51/8/60/4/6/78/88/90/9/203/7/9/17 to SEK. These were renumbered Θγ571-95 in the same order.
| Θγ521 | 2050 | - | ALCo | 1943 | 70532 | |
| Θγ522 | 2112 | - | ALCo | 1943 | 70594 | |
| Θγ523 | 2127 | - | ALCo | 1943 | 70609 | |
| Θγ524 | 2154 | - | Lima | 1943 | 8160 | |
| Θγ525 | 2206 | - | Lima | 1943 | 8212 | |
| Θγ526 | 2428 | - | ALCo | 1943 | 70777 | |
| Θγ527 | 2443 | - | ALCo | 1943 | 70792 | |
| Θγ528 | 2229 | - | Lima | 1943 | 8235 | |
| Θγ529 | 2456 | - | ALCo | 1943 | 70805 | |
| Θγ530 | 2573 | - | Lima | 1943 | 8275 | |
| Θγ531 | 3398 | - | Baldwin | 1944 | 70355 | |
| Θγ532 | 3524 | - | Baldwin | 1944 | 70481 | |
| Θγ533 | 1781 | - | Baldwin | 1942 | 67615 | |
| Θγ534 | 2166 | - | Lima | 1943 | 8172 | |
| Θγ535 | 2226 | - | Lima | 1943 | 8232 | |
| Θγ536 | 2365 | - | Baldwin | 1943 | 69622 | |
| Θγ537 | 2537 | - | Lima | 1943 | 8354 | |
| Θγ551 | 3338 | - | ALCo | 1944 | 71593 | |
| Θγ552 | 3352 | - | ALCo | 1944 | 71607 | |
| Θγ553 | 3364 | - | ALCo | 1944 | 71619 | |
| Θγ554 | 3374 | - | ALCo | 1944 | 71629 | |
| Θγ555 | 3375 | - | ALCo | 1944 | 71630 | |
| Θγ556 | 3327 | - | ALCo | 1944 | 71582 | |
| Θγ557 | 3347 | - | ALCo | 1944 | 71602 | |
| Θγ558 | 3357 | - | ALCo | 1944 | 71612 | |
| Θγ559 | 3360 | - | ALCo | 1944 | 71615 | |
| Θγ560 | 3372 | - | ALCo | 1944 | 71627 | |
| Θγ571 | 1740 | 736.011 | Baldwin | 1942 | 67574 | |
| Θγ572 | 1785 | 736.023 | Baldwin | 1942 | 67619 | |
| Θγ573 | 2070 | 736.040 | ALCo | 1943 | 70552 | |
| Θγ574 | 2746 | 736.055 | Baldwin | 1943 | 70009 | |
| Θγ575 | 3278 | 736.073 | ALCo | 1944 | 71533 | |
| Θγ576 | 3299 | 736.090 | ALCo | 1944 | 71554 | |
| Θγ577 | 3310 | 736.101 | ALCo | 1944 | 71565 | |
| Θγ578 | 3311 | 736.102 | ALCo | 1944 | 71566 | |
| Θγ579 | 3348 | 736.126 | ALCo | 1944 | 71603 | |
| Θγ580 | 3350 | 736.127 | ALCo | 1944 | 71605 | |
| Θγ581 | 3383 | 736.131 | Baldwin | 1944 | 70340 | |
| Θγ582 | 3387 | 736.135 | Baldwin | 1944 | 70344 | |
| Θγ583 | 3413 | 736.151 | Baldwin | 1944 | 70370 | |
| Θγ584 | 3420 | 736.158 | Baldwin | 1944 | 70377 | |
| Θγ585 | 3422 | 736.160 | Baldwin | 1944 | 70379 | |
| Θγ586 | 3426 | 736.164 | Baldwin | 1944 | 70383 | |
| Θγ587 | 3428 | 736.166 | Baldwin | 1944 | 70385 | |
| Θγ588 | 3622 | 736.178 | Lima | 1944 | 8535 | |
| Θγ589 | 3666 | 736.188 | Lima | 1944 | 8579 | |
| Θγ590 | 3668 | 736.190 | Lima | 1944 | 8581 | |
| Θγ591 | 3690 | 736.199 | Lima | 1944 | 8603 | |
| Θγ592 | 3694 | 736.203 | Lima | 1944 | 8607 | |
| Θγ593 | 3698 | 736.207 | Lima | 1944 | 8611 | |
| Θγ594 | 4418 | 736.209 | ALCo | 1945 | 73410 | |
| Θγ595 | 5740 | 736.217 | Lima | 1944 | 8678 |
A few still survive in scrapyard condition. Four are at Thessaloniki Old Depot (Θγ 525, 532, 535, 584), one is outside Thessaloniki current depot (Θγ 593) whilst one more survives at Tithorea depot (Θγ 576).[1] Θγ 575 is under overhaul at the Churnet Valley Railway in Great Britain. [2]