Единственная система из слегка разных модификаций Т3 и с разными кабинами.

Не сразу узнал, что вагоны сцеплены через "шарф", не понятно, почему тогда оба пантографа подняты, в автосцепке только низковольтное соединение?

Well, I am not 100% sure, but earlier, 7304 did not have an automatic coupler, and as 7303 earlier had covered couplers, they also were not automatic ... so probably there are only ordinary couplers between and a wire giving instructions to the rear wagon ... furthermore these are two different prototypes learnt to drive together years after ...

Yeah! In earlier photos 7304 is with ordinary coupler and I was suprised with new auto coupler. At the same time there are no sockets for low voltage cabel below front and back windows
Questions :)