Class 812 railcars were built in "Gosa" Smederevska Palanka, Serbia and Montenegro (Socialist Federal Republic of Yugoslavia then) from 1958. Ancestors of 812 railcars are Dmot railcars or class 126 made in Germany. They still can be seen on heritage tours in Austria and Germany. The popluar name for class 812 in former Yugoslavia is sinobus, what basically means rail bus. Their purpose was to be used mainly on smaller branchlines where there is no electrification. These railcars have been used ever since mainly in northern Serbia (Vojvodina) and Croatia.
I have seen some pictures of disused sets in Macedonia, what suggests that they were used there. I have also heard that railcars 812 were used in Bosnia and Hercegovina and Montenegro in 70s, but there is no pictures available to support that information. If you have one please email it to me.
Sinobus or railcars 812 have been used as single railmotors or sets of 2 or 3 cars depending on the need of particular line and/or availability of cars in fleet. Unfortunately, after the wars 1991 - 1999 there's more and more trains operating as single units consisting of a railmotor only. Some sets still consist of 2 cars (railmotor plus trailer), but it's very rare to see sets of 3 or more railcars. The fleet is ageing and rolling stock gets broken more often. It's not unusal that driver has to step out and fix the problem at the spot.
All 812s are equiped with toilets although some modernised sets have aircondition and automatic open doors.Not all cars are motors what means that if 2 cars set operates, there's shunting to change trailing end. Ideal situation is when a set consists of 3 cars (motor - trailer - motor) so there is no shunting to be done and seating capacity is maximised. It's nice when you have an opportunity to sit in unused driver's seat on opposite end of trailer and enjoy the view.
As some 812s were withdrawn from service Zeleznice Srbije (Railways of Serbia) decided to modernise some of the withdrawn sets and give them new life. First set consisting of a railmotor and trailer were modernised in 2003/04 in cooperation with local governments. The railmotor received new engine, max speed was increased while fuel usage was reduced. The whole set received new painting, aircondintioning, automatic open doors and new moder seats. The set operate on Novi Sad - Zrenjanin line twice a day. See pictures gallery>>>>
To see the map where sinobus has been used CLICK HERE
Note:
Red lines - represent lines where class 812 still operates
Black lines - epresent lines where class 812 operated in the past
The map is of former Yugoslav rail system (Jugoslovenske Zeleznice) and does not include current borders.
Information provided regarding use of class 812 at particular lines is the best to my knowledge and may not be correct
at the time you access it at the site.