1G46 thermal imager retrofit

A recent production patent filing shows that the Soviet era 1G46 (part of the 1A45 FCS) is being retrofitted with a thermal imaging channel. Named 1G46TT, the retrofit encompasses a major rework of the entire module. 

One of the major visual changes is the complete removal of the old faceplate of the sight and replacing it with a screen, indicating that the sight is now equipped with more advanced electronics and no longer relies on conventional mirror-based daylight optics as on the standard 1G46. 

Another interesting observation is that the retrofit retains the parallelogram mechanism, which most likely indicates that the sight block has not received independent stabilisation, unlike other modern Russian sight modules like Sosna-U. This means that, to retain accurate LoS and alignment with the barrel, mechanical input from the gun breech trunnion will be transmitted via a parallelogram arm. 

With a high probability that the new 1G46TT has received a thermal imaging channel, the optical head, which contains the mirror mechanism, will be operated mechanically, as with Sosna-U and PNM-T. 

As of this article's publication, it is unknown what was changed internally. External module observation and comparison to the standard 1G46 indicate that certain module sub-systems were gutted and replaced with new internal components to facilitate a digitised retrofit. This is evident in the presense of many new connectors and removable side panels. 

This retrofit patent has roots in an old attempt to modernise a 1A40 sight block and retrofit it with a thermal imaging channel. 

Lastly is a question of ergonomics and how this new large screen will perform with a very up-close seated position. Conclusions drawn from non-Russian ergonomic analysis showed excessive neck and shoulder muscle strains when operating a 1G46 for a prolonged amount of time. It would be interesting to see whether this new screen placement will solve this issue or not. 

I will be creating a follow-up post regarding the new 1G46TT, as I think it is an interesting retrofit. 

References: 

• ПАТЕНТ НА ПРОМЫШЛЕННЫЙ ОБРАЗЕЦ - ПРИЦЕЛ-ДАЛЬНОМЕР 1Г46ТТ RU154483