How does it work? I assume that they are just placed there to be within the field of view from the periscopes so that the driver has some reference point as to where the corners of the tank are?
Let me point out the model used by Jim for illustrations above is wrong - it shows regular, undirected light size indicator lamps typical for all Soviet tanks on top of "Vehicle Size Indicators" while in reality it was special devices with lamp deep inside the body, providing more or less directed beam of red light looking forward. If no obstacle, driver is not able to see the light as it is looking away from him. But if there is obstacle, driver will see red circle of reflected light on obstacle – and, if he is driving slowly enough, will be able to take measures (stop or steer away the vehicle). In day time, it is regular size indicstor
Speaking of this sort of stuff, the driver's instrument panel in the T-10 has two red warning lamps on its left and right edges that apparently warn the driver if the tank is too wide. But there are no sensors on the fenders or anything of the sort. Any idea on what they might be?
Not sure how it works, but there are similarly located lights on PT-76 light tank driver dashboard - may be it is direction indicators.....
Edited by Roman Alymov, 10 September 2019 - 0736 AM.