Wile E. Coyote wrote:
I found those data in Serbian railway society site (17 and 51 in 1917 and 126 in 1899), and also in Belgrade rail museum. Certainly I'll double check data. About 126 I found data that it was used in mines only, and it's still used today in mine "Rembas". 51 is in exploatation too (hauling museum train "Romantika"). They attached tender to it (I dont' know from which loco).
My bet would be that 1899 is the date when 126s (IIIq back then) started operating on then Hungarian lines which belong to Serbia since WW1. Like in Vojvodina. Wiki says that the first batch of these locos were manufactured in 1892-1893 but only 25 them, because MÁV was still purchasing the older IIIe type. Then production stopped. The next loco was built in 1896 for the Millenium celebrations. A single one. The loco was in production (again) from 1897 till 1907, this time in great numbers. According to Wiki from then on they were to be found on the Karlovac - Rijeka (Fiume) mountainous main line too and Subotica got a few locos as well to haul the Subotica - Budapest freight trains. I think, this is what the 1899 date stands for. Only MÁV and KsOd ever ordered these locos. To other companies could only get it "second hand". Mostly at the end of WW1. And I'd think that the loco was in line service (on freight trains) in Yugoslavia as well - at least for the first couple of years. Of these locos 68 went to Yugoslavia, 102 to Romania and 65 remained in Hungary.
An important note is that the only remaining loco of this type can be found in Serbia. The ex-MÁV 325,079, later JŽ 126-014 has survived as an industrial steam loco, and is still operational today.
I think the story of the 17 and 51 is roughly the same, too. In 1917 Serbia was under occupation, so probably the occupying Austrian-Hungarian monarchy used its own locos to some extent on Serbian lines as well. (Or they were used in Vojvodina.) The 17 was brand new then anyway. The two prototypes were built in 1915 and the production of the series started in 1916. After the war Romania got 109 of these locos, Yugoslavia 86 and 78 remained in Hungary.
On a completely different note:
I'm playing with your narrow gauge set right now and I'm having lots of fun. My only problem is the very low capacity of freight cars. For ore there is a self-unloading wagon which can transport 25 tonnes (quite a lot), there is also a hopper for ore + grain with 10 t capacity and a rather big tanker wagon. But the boxcar and the flatbed wagons are very tiny. They can only hold 5 t of cargo or 10 crates of goods. I'm servicing a low producing forest (only 64 t per month) with narrow gauge trains and my two six tile long trains are barely enough. They have a capacity of only 60 t. It would be an immense help if there was a freight car with 10 t of capacity for these other types of cargo as well. Historically lots of narrow gauge railways were built for wood transportation but with the Serbian Set currently it's extremely hard to pull it off. It provides an extra challenge, but maybe this is a bit too hard. I wouldn't like to imagine how long trains a forest producing 270 t of wood for example would need.
Today or tomorrow I'll also make the rest of the calculations, I just wanted to play a bit, and spent my free time with that on the weekend.