These machines have been deployed across the Turkey-Jarablus border crossing. Jarablus is located in the north of Aleppo province.
It has been speculated that these machines have been deployed before a Turkish intervention to create a safe zone. This speculation would be hard to fathom since Russia has warned against any further Turkish intervention in Syria.
Other theories also speculate that the reason for this is to clear another safe passage for Turkey to arm and aid terrorist groups that oppose the SDF and Syrian Arab Army. SDF are making rapid gains along the period regions. ISIS are the group controlling Jarablus, but it is well documented that Turkey fears a strong and unified Kurdish presence on its border, especially with Turkey undergoing a violent campaign against the Kurdistan Workers Party in its eastern provinces.
The Syrian Arab Army have made rapid gains in Latakia province and are moving towards Idlib province, a province that was overrun by terrorist forces including Al-Qaeda franchise Al-Nusra Front in March and April 2015. The province was overun by the terrorist forces who deployed from Turkey and had open direct assistance from Turkey and Saudi Arabia.