These men were known as the “black gang” because of the soot and coal dust they were covered in.
这些人被称为“black gang”，因为他们身上满是烟尘和煤灰。
英语百科
Peckham Boys
The Peckham Boys, also referred to as Black Gang, are a gang based in Peckham, South London. In 2011, Southwark Council identified the Peckham Young Guns as one of the three most active gangs in the Peckham area.