From: Third rock from the Sun.
Military Railroads in the Baltic States 1940 to 1945
WW2 German Railroads Baltic States
With the incorporation of the Baltic States into the Soviet Union in 1940, approximately 7.000 km (4.500 miles) of rail lines were added to the Soviet rail network. Of those 7.000 km (4.500 miles), approximately 2.900 km (1.900 miles) were wide gauge (1.524mm), 2.000 km (1.300 miles) were standard gauge (1.435mm) and 2.100 km (1.400 miles) were narrow gauge lines. Nearly all of the rail lines the Soviets inherited from the former Estonian, Latvian and Lithuanian railroad administrations were in excellent technical order; though very few were electrified. After the Soviet annexation, all of the railroad engines of the former Baltic States were re-identified with Cyrillic letters, though they were a direct translation of their Latin text equivalents.
In addition to the military and political forces brought in to the Baltic States, the Soviets also imported a large number Soviet railroad engines and rolling stock into the Baltic States. Interestingly, the Soviets did not begin to convert the standard and narrow gauge lines in Estonia, Latvia, and Lithuania over to wide gauge until March of 1941. It need be remembered that many of the existing rail lines in the Baltics originated from the Czarist period, thus they remained in the wide gauge throughout the interwar period. This allowed the Soviets to use many of the main trunk lines in the Baltics with no difficulties. The Soviets placed their primary rail conversion efforts in Lithuania as well as in the former Vilnius territory plus eastern Poland - that is, they converted those rail lines first which was closest to the German-Soviet border regions.
Many scenario designers seem to have missed this.
Edit: I should add that, for some reason, having the rail lines through the newly acquired Soviet territories already converted to Europe standard gauge is deeply ingrained in the war gaming community and has been for some time. One game where they got it right was in SPI's War in the East published long, long ago.
< Message edited by Lobster -- 9/1/2019 3:16:04 PM >