Work equipment collision at Readville, MA

Here is a news piece about a truck on rails rear ending another truck on rails that was pulling work equipment that occurred early Sat. morning April 13.
https://www.wcvb.com/article/mbta-commu ... t/43874213
Does anyone know what type of trucks these are (?Brandt) and what was in the cars they were pulling (?ballast)?
Thanks
Andy

The front vehicle is almost certain a tamper surfacing machine that was derailed. Unknown how the orange ballast dispenser is involved? Connected to tamper? If so, did tamper hit another vehicle or was it hit?

EDIT: maybe the orange unit was part of a ballast cleaner and / or ballast undercutter? If so, normal operation would have cleaner going other way and then tamper realigns track. Appears that cleaner backed into tamper that was stopped at the signal some views show. All speculation but where would someone stand / sit to protect back up move?