Ukraine: Why is a 50-year-old vehicle still being used on the battlefield?
The BMP1 first entered service in 1966, so why, more than 50 years later, is the infantry vehicle still being spotted on the battlefield for Russia and Ukraine?
When it first went into service within the Soviet Army the vehicle was revolutionary.
Forty thousand were built worldwide, with Ukraine and Russia having big stocks dating back to the USSR when they were part of the same army.
Other Warsaw Pact countries had a big stockpile, and many of them have donated to Ukraine during their latest conflict with Russia.
Another bonus of using the ageing BMP1 is that its familiar kit means there is little or no need for extra training.
Russia has even brought mothballed BMPs out of storage.
The dated design, however, has come with some problems, such as thin armour and a weak gun by modern standards, which has led to some heavy losses.
Another two versions of the BMP, the BMP2 and BMP3, have been manufactured, but the rollout was slowed due to the fall of the Soviet Union.
So, the BMP1 lives on, as it seems it is easier and cheaper to adapt and update an older vehicle than it is starting from scratch.