To add to what Grump said, Boston is huge on straight sticks. They can maneuver them into just about any spot in the city, and it's often that you'll see multiple sticks up at a job, in addition to a multitude of ground ladders, a well-known trademark of the BFD. They also like the ladder pipe concept and have stuck to it for years. Even at big jobs, they do very little tower ladder work in the FDNY sense of knocking down heavy fire from the bucket.
Since it's inception with Boston, the BFD started out with two 100' Sutphen Mid-Mount Towers back in the '70's. Aerial Tower 1(formerly Ladder 3) ran out of Engine 3's house in the South End, while Aerial Tower 2(formed in 1977 out of Ladder 27) was quartered with Engine 20 in Dorchester. The city then moved to one Tower with the introduction of the Tower Unit, a 100' E-One Rear-Mount running of the old Oliver Street station back in the '80's. When Oliver Street was demolished and Purchase Street opened, the Tower Unit's old E-One was replaced with a new one. In 2003, the Tower Unit was disbanded to form Tower Ladder 3. In 2002, Tower Ladder 10 was formed in Jamaica Plain(formerly Ladder 10). For one year, in 2007, Ladder 2 ran as Tower Ladder 2 in Eastie, but their rig went to Ladder 17 which became Tower Ladder 17 that same year. Now, there are two Towers in the city, TL 3 in Division 1, Downtown, and TL 10 in Division 2, in Jamaica Plain.